Rename packages to plugins

plugins/decman-flatpak/pyproject.toml

@@ -0,0 +1,20 @@
+[project]
+name = "decman-flatpak"
+version = "1.0.0"
+requires-python = ">=3.13"
+dependencies = ["decman==1.0.0"]
+
+[project.entry-points."decman.plugins"]
+flatpak = "decman.plugins.flatpak:Flatpak"
+
+[build-system]
+requires = ["setuptools>=61.0"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.packages.find]
+where = ["src"]
+namespaces = true
+include = ["decman.plugins*"]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]

plugins/decman-flatpak/src/decman/plugins/flatpak.py

@@ -0,0 +1,273 @@
+import shutil
+
+import decman.core.command as command
+import decman.core.error as errors
+import decman.core.module as module
+import decman.core.output as output
+import decman.core.store as _store
+import decman.plugins as plugins
+
+
+def packages(fn):
+    """
+    Annotate that this function returns a set of flatpak package names that should be installed.
+
+    Return type of ``fn``: ``set[str]``
+    """
+    fn.__flatpak__packages__ = True
+    return fn
+
+
+def user_packages(fn):
+    """
+    Annotate that this function returns a dict of users and flatpak packages that should be
+    installed.
+
+    Return type of ``fn``: ``dict[str, set[str]]``
+    """
+    fn.__flatpak__user__packages__ = True
+    return fn
+
+
+class Flatpak(plugins.Plugin):
+    """
+    Plugin that manages flatpak packages added directly to ``packages`` or declared by modules via
+    ``@flatpak.packages``. User packages are managed as well.
+    """
+
+    NAME = "flatpak"
+
+    def __init__(self) -> None:
+        self.packages: set[str] = set()
+        self.user_packages: dict[str, set[str]] = {}
+        self.ignored_packages: set[str] = set()
+        self.commands = FlatpakCommands()
+
+    def available(self) -> bool:
+        return shutil.which("flatpak") is not None
+
+    def process_modules(self, store: _store.Store, modules: set[module.Module]):
+        # These store keys are used to track changes in modules.
+        # This way when these change, module can be marked as changed
+        store.ensure("flatpaks_for_module", {})
+        store.ensure("user_flatpaks_for_module", {})
+
+        for mod in modules:
+            store["flatpaks_for_module"].setdefault(mod.name, set())
+            store["user_flatpaks_for_module"].setdefault(mod.name, {})
+
+            packages = plugins.run_method_with_attribute(mod, "__flatpak__packages__") or set()
+            user_packages = (
+                plugins.run_method_with_attribute(mod, "__flatpak__user__packages__") or {}
+            )
+
+            if store["flatpaks_for_module"][mod.name] != packages:
+                mod._changed = True
+                output.print_debug(
+                    f"Module '{mod.name}' set to changed due to modified system flatpaks."
+                )
+
+            if store["user_flatpaks_for_module"][mod.name] != user_packages:
+                mod._changed = True
+                output.print_debug(
+                    f"Module '{mod.name}' set to changed due to modified user flatpaks."
+                )
+
+            self.packages |= packages
+            for user, flatpaks in user_packages.items():
+                self.user_packages.setdefault(user, set()).update(flatpaks)
+
+            store["flatpaks_for_module"][mod.name] = packages
+            store["user_flatpaks_for_module"][mod.name] = user_packages
+
+    def apply(
+        self, store: _store.Store, dry_run: bool = False, params: list[str] | None = None
+    ) -> bool:
+        pm = FlatpakInterface(self.commands)
+
+        try:
+            self.apply_packages(pm, None, self.packages, self.ignored_packages, dry_run)
+
+            for user, packages in self.user_packages.items():
+                self.apply_packages(pm, user, packages, self.ignored_packages, dry_run)
+        except errors.CommandFailedError as error:
+            output.print_error("Running a flatpak command failed.")
+            output.print_error(
+                "Flatpak command exited with an unexpected return code. You may have cancelled a "
+                "flatpak operation."
+            )
+            output.print_error(str(error))
+            if error.output:
+                output.print_command_output(error.output)
+            output.print_traceback()
+            return False
+        return True
+
+    def apply_packages(
+        self,
+        flatpak: "FlatpakInterface",
+        user: str | None,
+        packages: set[str],
+        ignored_packages: set[str],
+        dry_run: bool,
+    ):
+        currently_installed = flatpak.get_apps(user)
+        to_remove = currently_installed - packages - ignored_packages
+        to_install = packages - currently_installed - ignored_packages
+
+        for_user_msg = f" for {user}" if user else ""
+
+        if to_remove:
+            output.print_list(f"Removing flatpak packages{for_user_msg}:", sorted(to_remove))
+            if not dry_run:
+                flatpak.remove(to_remove, user)
+
+        output.print_summary(f"Upgrading packages{for_user_msg}.")
+        if not dry_run:
+            flatpak.upgrade(user)
+
+        if to_install:
+            output.print_list(f"Installing flatpak packages{for_user_msg}:", sorted(to_install))
+            if not dry_run:
+                flatpak.install(to_install, user)
+
+
+class FlatpakCommands:
+    def list_apps(self, as_user: bool) -> list[str]:
+        """
+        Running this command outputs a newline separated list of installed flatpak application IDs.
+
+        If ``as_user`` is ``True``, run the command as the user whose packages should be listed.
+
+        NOTE: The first line says 'Application ID' and should be ignored.
+        """
+        return [
+            "flatpak",
+            "list",
+            "--app",
+            "--user" if as_user else "--system",
+            "--columns",
+            "application",
+        ]
+
+    def install(self, pkgs: set[str], as_user: bool) -> list[str]:
+        """
+        Running this command installs all listed packages, and their dependencies/runtimes
+        automatically.
+
+        If ``as_user`` is ``True``, run the command as the user for whom packages are installed.
+        """
+        return [
+            "flatpak",
+            "install",
+            "--user" if as_user else "--system",
+        ] + sorted(pkgs)
+
+    def upgrade(self, as_user: bool) -> list[str]:
+        """
+        Updates all installed flatpaks including runtimes and dependencies.
+
+        If ``as_user`` is ``True``, run the command as the user whose flatpaks are updated.
+        """
+        return [
+            "flatpak",
+            "update",
+            "--user" if as_user else "--system",
+        ]
+
+    def remove(self, pkgs: set[str], as_user: bool) -> list[str]:
+        """
+        Running this command will remove the listed packages.
+
+        If ``as_user`` is ``True``, run the command as the user for whom packages are removed.
+        """
+
+        return [
+            "flatpak",
+            "remove",
+            "--user" if as_user else "--system",
+        ] + sorted(pkgs)
+
+    def remove_unused(self, as_user: bool) -> list[str]:
+        """
+        This will remove all unused flatpak dependencies and runtimes.
+
+        If ``as_user`` is ``True``, run the command as the user for whom packages are removed.
+        """
+        return [
+            "flatpak",
+            "remove",
+            "--unused",
+            "--user" if as_user else "--system",
+        ]
+
+
+class FlatpakInterface:
+    """
+    High level interface for running pacman commands.
+
+    On failure methods raise a ``CommandFailedError``.
+    """
+
+    def __init__(self, commands: FlatpakCommands) -> None:
+        self._commands = commands
+
+    def get_apps(self, user: str | None = None) -> set[str]:
+        """
+        Returns a set of installed flatpak apps.
+
+        If ``user`` is set, returns flatpak apps for that user.
+        """
+        as_user = user is not None
+
+        cmd = self._commands.list_apps(as_user=as_user)
+        _, packages_text = command.check_run_result(
+            cmd, command.run(cmd, user=user, mimic_login=as_user)
+        )
+        packages = packages_text.strip().split("\n")
+
+        # In case no apps are installed, the list contains this
+        if "" in packages:
+            packages.remove("")
+
+        return set(packages)
+
+    def install(self, packages: set[str], user: str | None = None):
+        """
+        Installs the given packages.
+
+        If ``user`` is set, installs packages for that user.
+        """
+        if not packages:
+            return
+
+        as_user = user is not None
+
+        cmd = self._commands.install(packages, as_user)
+        command.prg(cmd, user=user, mimic_login=as_user)
+
+    def upgrade(self, user: str | None = None):
+        """
+        Upgrades all packages.
+
+        If ``user`` is set, upgrades packages for that user.
+        """
+        as_user = user is not None
+        cmd = self._commands.upgrade(as_user)
+        command.prg(cmd, user=user, mimic_login=as_user)
+
+    def remove(self, packages: set[str], user: str | None = None):
+        """
+        Removes the given packages as well as unused dependencies.
+
+        If ``user`` is set, removes packages for that user.
+        """
+        if not packages:
+            return
+
+        as_user = user is not None
+        cmd = self._commands.remove(packages, as_user)
+        command.prg(cmd, user=user, mimic_login=as_user)
+
+        cmd = self._commands.remove_unused(as_user)
+        command.prg(cmd, user=user, mimic_login=as_user)

plugins/decman-pacman/pyproject.toml

@@ -0,0 +1,25 @@
+[project]
+name = "decman-pacman"
+version = "1.0.0"
+requires-python = ">=3.13"
+dependencies = [
+  "decman==1.0.0",
+  "pyalpm",
+  "requests",
+]
+
+[project.entry-points."decman.plugins"]
+pacman = "decman.plugins.pacman:Pacman"
+aur = "decman.plugins.aur:AUR"
+
+[build-system]
+requires = ["setuptools>=61.0"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.packages.find]
+where = ["src"]
+namespaces = true
+include = ["decman.plugins*"]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]

plugins/decman-pacman/src/decman/plugins/aur/__init__.py

@@ -0,0 +1,258 @@
+import os
+import shutil
+
+import pyalpm
+from decman.plugins.aur.commands import AurCommands, AurPacmanInterface
+from decman.plugins.aur.error import (
+    AurRPCError,
+    DependencyCycleError,
+    ForeignPackageManagerError,
+    PKGBUILDParseError,
+)
+from decman.plugins.aur.fpm import ForeignPackageManager
+from decman.plugins.aur.package import CustomPackage, PackageSearch
+
+import decman.config as config
+import decman.core.error as errors
+import decman.core.module as module
+import decman.core.output as output
+import decman.core.store as _store
+import decman.plugins as plugins
+
+# Re-exports
+__all__ = [
+    "AUR",
+    "AurCommands",
+    "CustomPackage",
+    "packages",
+    "custom_packages",
+]
+
+
+def packages(fn):
+    """
+    Annotate that this function returns a set of AUR package names that should be installed.
+
+    Return type of ``fn``: ``set[str]``
+    """
+    fn.__aur__packages__ = True
+    return fn
+
+
+def custom_packages(fn):
+    """
+    Annotate that this function returns a set of ``CustomPackage``s that should be installed.
+
+    Return type of ``fn``: ``set[CustomPackage]``
+    """
+    fn.__custom__packages__ = True
+    return fn
+
+
+class AUR(plugins.Plugin):
+    """
+    Plugin that manages additional pacman packages installed outside the pacman repos.
+
+    AUR packages are added directly to ``packages`` or declared by modules via ``@aur.packages``.
+
+    Custom packages are added directly to ``custom_packages`` or declared by modules via
+    ``@aur.custom_packages``.
+    """
+
+    NAME = "aur"
+
+    def __init__(self) -> None:
+        self.packages: set[str] = set()
+        self.custom_packages: set[CustomPackage] = set()
+        self.ignored_packages: set[str] = set()
+        self.commands: AurCommands = AurCommands()
+
+        self.database_signature_level = pyalpm.SIG_DATABASE_OPTIONAL
+        self.database_path = "/var/lib/pacman/"
+
+        self.aur_rpc_timeout: int = 30
+        self.print_highlights: bool = True
+        self.keywords: set[str] = {
+            "pacsave",
+            "pacnew",
+            # These cause too many false positives IMO
+            # "warning",
+            # "error",
+            # "note",
+        }
+        self.build_dir: str = "/tmp/decman/build"
+        self.makepkg_user: str = "nobody"
+
+    def available(self) -> bool:
+        return (
+            shutil.which("pacman") is not None
+            and shutil.which("git") is not None
+            and shutil.which("mkarchroot") is not None
+        )
+
+    def process_modules(self, store: _store.Store, modules: set[module.Module]):
+        # This is used to track changes in modules.
+        store.ensure("aur_packages_for_module", {})
+        store.ensure("custom_packages_for_module", {})
+
+        for mod in modules:
+            store["aur_packages_for_module"].setdefault(mod.name, set())
+            store["custom_packages_for_module"].setdefault(mod.name, set())
+
+            aur_packages = plugins.run_method_with_attribute(mod, "__aur__packages__") or set()
+            custom_packages = (
+                plugins.run_method_with_attribute(mod, "__custom__packages__") or set()
+            )
+            custom_package_strs = set(map(str, custom_packages))
+
+            if store["aur_packages_for_module"][mod.name] != aur_packages:
+                mod._changed = True
+                output.print_debug(
+                    f"Module '{mod.name}' set to changed due to modified aur packages."
+                )
+
+            if store["custom_packages_for_module"][mod.name] != custom_package_strs:
+                mod._changed = True
+                output.print_debug(
+                    f"Module '{mod.name}' set to changed due to modified custom packages."
+                )
+
+            self.packages |= aur_packages
+            self.custom_packages |= custom_packages
+
+            store["aur_packages_for_module"][mod.name] = aur_packages
+            store["custom_packages_for_module"][mod.name] = custom_package_strs
+
+    def apply(
+        self, store: _store.Store, dry_run: bool = False, params: list[str] | None = None
+    ) -> bool:
+        params = params or []
+        upgrade_devel = "aur-upgrade-devel" in params
+        force = "aur-force" in params
+        pkg_cache_dir = os.path.join(config.cache_dir, "aur/")
+
+        if not dry_run:
+            try:
+                os.makedirs(pkg_cache_dir, exist_ok=True)
+            except OSError as error:
+                output.print_error(
+                    "Failed to ensure AUR package cache directory exists: "
+                    f"{error.strerror or error}"
+                )
+                output.print_traceback()
+
+                return False
+
+        try:
+            package_search = PackageSearch(self.aur_rpc_timeout)
+            for custom_package in self.custom_packages:
+                package_search.add_custom_pkg(custom_package.parse(self.commands))
+            pm = AurPacmanInterface(
+                self.commands,
+                self.print_highlights,
+                self.keywords,
+                self.database_signature_level,
+                self.database_path,
+            )
+            fpm = ForeignPackageManager(
+                store,
+                pm,
+                package_search,
+                self.commands,
+                pkg_cache_dir,
+                self.build_dir,
+                self.makepkg_user,
+            )
+
+            custom_package_names = {p.pkgname for p in self.custom_packages}
+            currently_installed_native = pm.get_native_explicit()
+            currently_installed_foreign = pm.get_foreign_explicit()
+            orphans = pm.get_foreign_orphans()
+
+            to_remove = (
+                (currently_installed_foreign | orphans)
+                - self.packages
+                - custom_package_names
+                - self.ignored_packages
+            )
+
+            actually_to_remove = set()
+            to_set_as_dependencies = set()
+
+            dependants_to_keep = (
+                self.packages
+                | custom_package_names
+                | currently_installed_native
+                # don't remove ignored packages' dependencies
+                | (self.ignored_packages & currently_installed_foreign)
+            )
+            for package in to_remove:
+                dependants = pm.get_dependants(package)
+                if any(dependant in dependants_to_keep for dependant in dependants):
+                    to_set_as_dependencies.add(package)
+                else:
+                    actually_to_remove.add(package)
+
+            if actually_to_remove:
+                output.print_list("Removing foreign packages:", sorted(actually_to_remove))
+                if not dry_run:
+                    pm.remove(actually_to_remove)
+
+            if to_set_as_dependencies:
+                output.print_list(
+                    "Setting previously explicitly installed foreign packages as dependencies:",
+                    sorted(to_set_as_dependencies),
+                )
+                if not dry_run:
+                    pm.set_as_dependencies(to_set_as_dependencies)
+
+            output.print_summary("Upgrading foreign packages.")
+            if not dry_run:
+                fpm.upgrade(upgrade_devel, force, self.ignored_packages)
+
+            to_install = (
+                (self.packages | custom_package_names)
+                - currently_installed_foreign
+                - self.ignored_packages
+            )
+            output.print_list("Installing foreign packages:", sorted(to_install))
+
+            if not dry_run:
+                fpm.install(list(to_install), force=force)
+        except AurRPCError as error:
+            output.print_error("Failed to fetch data from AUR RPC.")
+            output.print_error(str(error))
+            output.print_traceback()
+            return False
+        except DependencyCycleError as error:
+            output.print_error("Foreign package dependency cycle detected.")
+            output.print_error(str(error))
+            output.print_traceback()
+            return False
+        except PKGBUILDParseError as error:
+            output.print_error("Failed to parse a CustomPackage PKGBUILD.")
+            output.print_error(str(error))
+            output.print_traceback()
+            return False
+        except ForeignPackageManagerError as error:
+            output.print_error("Foreign package manager failed.")
+            output.print_error(str(error))
+            output.print_traceback()
+            return False
+        except pyalpm.error as error:
+            output.print_error("Failed to query pacman databases with pyalpm.")
+            output.print_error(str(error))
+            output.print_traceback()
+            return False
+        except errors.CommandFailedError as error:
+            output.print_error(
+                "AUR command exited with an unexpected return code. You may have cancelled a "
+                "pacman operation."
+            )
+            output.print_error(str(error))
+            if error.output:
+                output.print_command_output(error.output)
+            output.print_traceback()
+            return False
+
+        return True

plugins/decman-pacman/src/decman/plugins/aur/commands.py

@@ -0,0 +1,199 @@
+import decman.plugins.pacman as pacman
+import pyalpm
+
+import decman.config as config
+import decman.core.command as command
+
+
+class AurCommands(pacman.PacmanCommands):
+    def install_as_dependencies(self, pkgs: set[str]) -> list[str]:
+        """
+        Running this command installs the given packages from pacman repositories.
+        The packages are installed as dependencies.
+        """
+        return ["pacman", "-S", "--needed", "--asdeps"] + list(pkgs)
+
+    def install_files_as_dependencies(self, pkg_files: list[str]) -> list[str]:
+        """
+        Running this command installs the given packages files as dependencies.
+        """
+        return ["pacman", "-U", "--asdeps"] + pkg_files
+
+    def compare_versions(self, installed_version: str, new_version: str) -> list[str]:
+        """
+        Running this command outputs -1 when the installed version is older than the new version.
+        """
+        return ["vercmp", installed_version, new_version]
+
+    def git_clone(self, repo: str, dest: str) -> list[str]:
+        """
+        Running this command clones a git repository to the the given destination.
+        """
+        return ["git", "clone", repo, dest]
+
+    def git_diff(self, from_commit: str) -> list[str]:
+        """
+        Running this command outputs the difference between the given commit and
+        the current state of the repository.
+        """
+        return ["git", "diff", from_commit]
+
+    def git_get_commit_id(self) -> list[str]:
+        """
+        Running this command outputs the current commit id.
+        """
+        return ["git", "rev-parse", "HEAD"]
+
+    def git_log_commit_ids(self) -> list[str]:
+        """
+        Running this command outputs commit hashes of the repository.
+        """
+        return ["git", "log", "--format=format:%H"]
+
+    def review_file(self, file: str) -> list[str]:
+        """
+        Running this command outputs a file for the user to see.
+        """
+        return ["less", file]
+
+    def make_chroot(self, chroot_dir: str, with_pkgs: set[str]) -> list[str]:
+        """
+        Running this command creates a new arch chroot to the chroot directory and installs the
+        given packages there.
+        """
+        return ["mkarchroot", chroot_dir] + list(with_pkgs)
+
+    def install_chroot(self, chroot_dir: str, packages: list[str]):
+        """
+        Running this command installs the given packages to the given chroot.
+        """
+        return [
+            "arch-nspawn",
+            chroot_dir,
+            "pacman",
+            "-S",
+            "--needed",
+            "--noconfirm",
+        ] + packages
+
+    def resolve_real_name_chroot(self, chroot_dir: str, pkg: str) -> list[str]:
+        """
+        This command prints a real name of a package.
+        For example, it prints the package which provides a virtual package.
+        """
+        return [
+            "arch-nspawn",
+            chroot_dir,
+            "pacman",
+            "-Sddp",
+            "--print-format=%n",
+            pkg,
+        ]
+
+    def remove_chroot(self, chroot_dir: str, packages: set[str]):
+        """
+        Running this command removes the given packages from the given chroot.
+        """
+        return ["arch-nspawn", chroot_dir, "pacman", "-Rsu", "--noconfirm"] + list(packages)
+
+    def make_chroot_pkg(
+        self, chroot_wd_dir: str, user: str, pkgfiles_to_install: list[str]
+    ) -> list[str]:
+        """
+        Running this command creates a package file using the given chroot.
+        The package is created as the user and the pkg_files_to_install are installed
+        in the chroot before the package is created.
+        """
+        makechrootpkg_cmd = ["makechrootpkg", "-c", "-r", chroot_wd_dir, "-U", user]
+
+        for pkgfile in pkgfiles_to_install:
+            makechrootpkg_cmd += ["-I", pkgfile]
+
+        return makechrootpkg_cmd
+
+    def print_srcinfo(self) -> list[str]:
+        """
+        Running this command prints SRCINFO generated from the package in the current
+        working directory.
+        """
+        return ["makepkg", "--printsrcinfo"]
+
+
+class AurPacmanInterface(pacman.PacmanInterface):
+    """
+    High level interface for running pacman commands.
+
+    On failure methods raise a ``CommandFailedError``.
+    """
+
+    def __init__(
+        self,
+        commands: AurCommands,
+        print_highlights: bool,
+        keywords: set[str],
+        dbsiglevel: int,
+        dbpath: str,
+    ) -> None:
+        super().__init__(commands, print_highlights, keywords, dbsiglevel, dbpath)
+        self._installable: dict[str, bool] = {}
+        self._aur_commands = commands
+
+    def get_foreign_orphans(self) -> set[str]:
+        """
+        Returns a set of orphaned foreign packages.
+        """
+        out: set[str] = set()
+        for pkg in self._handle.get_localdb().pkgcache:
+            if pkg.reason != pyalpm.PKG_REASON_DEPEND:
+                continue
+            if pkg.compute_requiredby():
+                continue
+            if not self._is_native(pkg.name):
+                out.add(pkg.name)
+        return out
+
+    def is_installable(self, pkg: str) -> bool:
+        """
+        Returns True if a package can be installed using pacman.
+        """
+        return pkg in self._name_index or pacman.strip_dependency(pkg) in self._provides_index
+
+    def get_versioned_foreign_packages(self) -> list[tuple[str, str]]:
+        """
+        Returns a list of installed packages and their versions that aren't from pacman databases,
+        basically AUR packages.
+        """
+        out: list[tuple[str, str]] = []
+        for pkg in self._handle.get_localdb().pkgcache:
+            if not self._is_native(pkg.name):
+                out.append((pkg.name, pkg.version))
+        return out
+
+    def install_dependencies(self, deps: set[str]):
+        """
+        Installs the given dependencies.
+        """
+        if not deps:
+            return
+
+        cmd = self._aur_commands.install_as_dependencies(deps)
+        pacman_output = command.prg(cmd)
+        self.print_highlighted_pacman_messages(pacman_output)
+
+    def install_files(self, files: list[str], as_explicit: set[str]):
+        """
+        Installs the given files first as dependencies. Then the packages listed in as_explicit are
+        installed explicitly.
+        """
+        if not files:
+            return
+
+        cmd = self._aur_commands.install_files_as_dependencies(files)
+        pacman_output = command.prg(cmd)
+        self.print_highlighted_pacman_messages(pacman_output)
+
+        if not as_explicit:
+            return
+
+        cmd = self._commands.set_as_explicit(as_explicit)
+        command.prg(cmd, pty=config.debug_output)

plugins/decman-pacman/src/decman/plugins/aur/error.py

@@ -0,0 +1,40 @@
+class ForeignPackageManagerError(Exception):
+    """
+    Error raised from the ForeignPackageManager
+    """
+
+
+class DependencyCycleError(Exception):
+    """
+    Error raised when a dependency cycle is detected involving foreign packages.
+    """
+
+    def __init__(self, package1: str, package2: str):
+        super().__init__(
+            f"Foreign package dependency cycle detected involving '{package1}' "
+            f"and '{package2}'. Foreign package dependencies are also required "
+            "during package building and therefore dependency cycles cannot be handled."
+        )
+
+
+class PKGBUILDParseError(Exception):
+    """
+    Error raised when parsing a PKGBUILD fails.
+    """
+
+    def __init__(self, git_url: str | None, pkgbuild_directory: str | None, message: str) -> None:
+        # Only one of these should be set
+        self.pkgbuild_source = git_url or pkgbuild_directory
+        self.message = message
+        super().__init__(f"Failed to parse PKGBUILD from '{self.pkgbuild_source}': {message}")
+
+
+class AurRPCError(Exception):
+    """
+    Error raised when accessing AUR RPC fails.
+    """
+
+    def __init__(self, message: str, url: str):
+        self.message = message
+        self.url = url
+        super().__init__(f"Failed to complete AUR RPC request to '{url}': {message}")

plugins/decman-pacman/src/decman/plugins/aur/fpm.py

@@ -0,0 +1,814 @@
+import os
+import shutil
+import time
+import typing
+
+from decman.plugins.aur.commands import AurCommands
+from decman.plugins.aur.error import ForeignPackageManagerError
+from decman.plugins.aur.package import AurPacmanInterface, PackageSearch
+from decman.plugins.aur.resolver import DepGraph, ForeignPackage
+
+import decman.config as config
+import decman.core.command as command
+import decman.core.error as errors
+import decman.core.output as output
+import decman.core.store as _store
+
+
+def find_latest_cached_package(store: _store.Store, package: str) -> tuple[str, str] | None:
+    """
+    Returns the latest version and path of a package stored in the built packages cache as a
+    tuple (version, path).
+    """
+    store.ensure("package_file_cache", {})
+    entries = store["package_file_cache"].get(package)
+
+    if entries is None:
+        return None
+
+    latest_version = None
+    latest_path = None
+    latest_timestamp = 0
+
+    for version, path, timestamp in entries:
+        if latest_timestamp < timestamp and os.path.exists(path):
+            latest_timestamp = timestamp
+            latest_version = version
+            latest_path = path
+
+    output.print_debug(f"Latest file for {package} is '{latest_path}'.")
+
+    if latest_path is None:
+        return None
+
+    assert latest_version is not None, "If latest_path is set, then latest_version is set."
+    return (latest_version, latest_path)
+
+
+def add_package_to_cache(store: _store.Store, package: str, version: str, path_to_built_pkg: str):
+    """
+    Adds a built package to the package file cache. Tries to remove excess cached packages.
+    """
+    store.ensure("package_file_cache", {})
+
+    new_entry = (version, path_to_built_pkg, int(time.time()))
+    entries = store["package_file_cache"].get(package, [])
+    for _, already_cached_path, __ in entries:
+        if already_cached_path == path_to_built_pkg:
+            output.print_debug(
+                f"Trying to cache {package} version {version}, but the version is already cached: "
+                f"{already_cached_path}"
+            )
+            return
+    entries.append(new_entry)
+
+    store["package_file_cache"][package] = entries
+    clean_package_cache(store, package)
+
+
+def clean_package_cache(store: _store.Store, package: str):
+    oldest_path = None
+    oldest_timestamp = None
+    index_of_oldest = None
+
+    entries = store["package_file_cache"][package]
+    output.print_debug(f"Package cache has {len(entries)} entries.")
+
+    number_of_packages_stored_in_cache = 3
+
+    if len(entries) <= number_of_packages_stored_in_cache:
+        output.print_debug("Old files will not be removed.")
+        return
+
+    for index, entry in enumerate(entries):
+        _, path, timestamp = entry
+        if oldest_timestamp is None or oldest_timestamp > timestamp:
+            oldest_timestamp = timestamp
+            oldest_path = path
+            index_of_oldest = index
+
+    output.print_debug(f"Oldest cached file for {package} is '{oldest_path}'.")
+    if oldest_path is None:
+        return
+    assert index_of_oldest is not None
+
+    entries.pop(index_of_oldest)
+    if os.path.exists(oldest_path):
+        output.print_debug(f"Removing '{oldest_path}' from the package cache.")
+        try:
+            os.remove(oldest_path)
+        except OSError as e:
+            output.print_error(f"Failed to remove file '{oldest_path}' from the package cache.")
+            output.print_error(e.strerror or str(e))
+            output.print_error("You'll have to remove the file manually.")
+
+    store["package_file_cache"][package] = entries
+
+
+def is_devel(package: str) -> bool:
+    """
+    Returns True if the given package is a devel package.
+    """
+    devel_suffixes = [
+        "-git",
+        "-hg",
+        "-bzr",
+        "-svn",
+        "-cvs",
+        "-darcs",
+    ]
+    for suffix in devel_suffixes:
+        if package.endswith(suffix):
+            return True
+    return False
+
+
+class ResolvedDependencies:
+    """
+    Result of dependency resolution.
+    """
+
+    def __init__(self) -> None:
+        self.pacman_deps: set[str] = set()
+        self.foreign_pkgs: set[str] = set()
+        self.foreign_dep_pkgs: set[str] = set()
+        self.foreign_build_dep_pkgs: set[str] = set()
+        self.build_order: list[str] = []
+        self.packages: dict[str, ForeignPackage] = {}
+        self._pkgbases_to_pkgs: dict[str, set[str]] = {}
+        self._pkgs_to_pkgbases: dict[str, str] = {}
+
+    def add_pkgbase_info(self, pkgname: str, pkgbase: str):
+        """
+        Adds information about a which package belongs in which package base.
+        """
+        pkgs = self._pkgbases_to_pkgs.get(pkgbase, set())
+        pkgs.add(pkgname)
+        self._pkgbases_to_pkgs[pkgbase] = pkgs
+        self._pkgs_to_pkgbases[pkgname] = pkgbase
+
+    def get_pkgbase(self, pkgname: str) -> str:
+        """
+        Returns the package base of an package.
+        """
+        return self._pkgs_to_pkgbases[pkgname]
+
+    def get_pkgs_with_common_pkgbase(self, pkgname: str) -> set[str]:
+        """
+        Returns all packages that have the same package base as the given package.
+        """
+        pkgbase = self._pkgs_to_pkgbases[pkgname]
+        return self._pkgbases_to_pkgs[pkgbase]
+
+    def all_pkgbases(self) -> list[str]:
+        """
+        Returns all pkgbases.
+        """
+        return list(self._pkgbases_to_pkgs)
+
+    def get_some_pkgname(self, pkgbase: str) -> str:
+        """
+        Returns some package name that the given pkgbase has.
+        """
+        return list(self._pkgbases_to_pkgs[pkgbase])[0]
+
+
+class ForeignPackageManager:
+    """
+    Class for dealing with foreign packages.
+    """
+
+    def __init__(
+        self,
+        store: _store.Store,
+        pacman: AurPacmanInterface,
+        search: PackageSearch,
+        commands: AurCommands,
+        pkg_cache_dir: str,
+        build_dir: str,
+        makepkg_user: str,
+    ):
+        self._store = store
+        self._pacman = pacman
+        self._search = search
+        self._commands = commands
+        self._pkg_cache_dir = pkg_cache_dir
+        self._build_dir = build_dir
+        self._makepkg_user = makepkg_user
+
+    def upgrade(
+        self,
+        upgrade_devel: bool = False,
+        force: bool = False,
+        ignored_pkgs: typing.Optional[set[str]] = None,
+    ):
+        """
+        Upgrades all foreign packages.
+        """
+        if ignored_pkgs is None:
+            ignored_pkgs = set()
+
+        output.print_info("Determining foreign packages to upgrade.")
+
+        all_foreign_pkgs = self._pacman.get_versioned_foreign_packages()
+        all_explicit_foreign_pkgs = set(self._pacman.get_foreign_explicit())
+        output.print_debug(f"Foreign packages to check for upgrades: {all_foreign_pkgs}")
+
+        self._search.try_caching_packages(list(map(lambda p: p[0], all_foreign_pkgs)))
+
+        as_explicit = []
+        as_deps = []
+        for pkg, ver in all_foreign_pkgs:
+            if pkg in ignored_pkgs:
+                continue
+
+            info = self._search.get_package_info(pkg)
+            if info is None:
+                raise ForeignPackageManagerError(
+                    f"Failed to find '{pkg}' from AUR or user provided packages."
+                )
+
+            if self.should_upgrade_package(pkg, ver, info.version, upgrade_devel):
+                if pkg in all_explicit_foreign_pkgs:
+                    as_explicit.append(pkg)
+                else:
+                    as_deps.append(pkg)
+
+        output.print_debug(
+            f"The following foreign packages will be upgraded: {' '.join(as_explicit)}"
+        )
+
+        self.install(as_explicit, as_deps, force)
+
+    def install(
+        self,
+        foreign_pkgs: list[str],
+        foreign_dep_pkgs: typing.Optional[list[str]] = None,
+        force: bool = False,
+    ):
+        """
+        Installs the given foreign packages and their dependencies (both pacman/AUR).
+        """
+
+        if foreign_dep_pkgs is None:
+            foreign_dep_pkgs = []
+
+        if len(foreign_pkgs) == 0 and len(foreign_dep_pkgs) == 0:
+            return
+
+        resolved_dependencies = self.resolve_dependencies(foreign_pkgs, foreign_dep_pkgs)
+
+        output.print_list(
+            "The following foreign packages will be installed explicitly:",
+            sorted(resolved_dependencies.foreign_pkgs),
+        )
+
+        output.print_list(
+            "The following foreign packages will be installed as dependencies:",
+            sorted(resolved_dependencies.foreign_dep_pkgs),
+        )
+
+        output.print_list(
+            "The following foreign packages will be built in order to install other packages. "
+            "They will not be installed:",
+            sorted(resolved_dependencies.foreign_build_dep_pkgs),
+        )
+
+        if not output.prompt_confirm("Proceed?", default=True):
+            raise ForeignPackageManagerError("Installing aborted by the user.")
+
+        output.print_summary("Installing foreign package dependencies from pacman.")
+        self._pacman.install_dependencies(resolved_dependencies.pacman_deps)
+
+        try:
+            with PackageBuilder(
+                self._search,
+                self._store,
+                self._pacman,
+                resolved_dependencies,
+                self._commands,
+                self._pkg_cache_dir,
+                self._build_dir,
+                self._makepkg_user,
+            ) as builder:
+                while resolved_dependencies.build_order:
+                    to_build = resolved_dependencies.build_order.pop(0)
+
+                    pkgbase = resolved_dependencies.get_pkgbase(to_build)
+                    package_names = resolved_dependencies.get_pkgs_with_common_pkgbase(to_build)
+
+                    packages = [
+                        resolved_dependencies.packages[pkgname] for pkgname in package_names
+                    ]
+
+                    builder.build_packages(pkgbase, packages, force)
+        except OSError as e:
+            raise ForeignPackageManagerError("Failed to build packages.") from e
+
+        packages_to_install = resolved_dependencies.foreign_pkgs
+        packages_to_install |= resolved_dependencies.foreign_dep_pkgs
+
+        package_files_to_install = []
+        for pkg in packages_to_install:
+            built_pkg = find_latest_cached_package(self._store, pkg)
+            assert built_pkg is not None
+            _, path = built_pkg
+            package_files_to_install.append(path)
+
+        if package_files_to_install or force:
+            output.print_summary("Installing foreign packages.")
+            self._pacman.install_files(
+                package_files_to_install,
+                as_explicit=resolved_dependencies.foreign_pkgs,
+            )
+        else:
+            output.print_summary("No packages to install.")
+
+    def resolve_dependencies(
+        self,
+        foreign_pkgs: list[str],
+        foreign_dep_pkgs: typing.Optional[list[str]] = None,
+    ) -> ResolvedDependencies:
+        """
+        Resolves foreign dependencies of foreign packages.
+        """
+
+        output.print_info("Resolving foreign package dependencies.")
+        output.print_debug(f"Packages: {foreign_pkgs}")
+
+        if foreign_dep_pkgs is None:
+            foreign_dep_pkgs = []
+
+        result = ResolvedDependencies()
+        result.foreign_pkgs = set(foreign_pkgs)
+        result.foreign_dep_pkgs = set(foreign_dep_pkgs)
+
+        graph = DepGraph()
+
+        for name in foreign_pkgs + foreign_dep_pkgs:
+            graph.add_requirement(name, None)
+
+        seen_packages = set(foreign_pkgs + foreign_dep_pkgs)
+        to_process = foreign_pkgs + foreign_dep_pkgs
+        total_processed = 0
+
+        self._search.try_caching_packages(to_process)
+
+        def process_dep(pkgname: str, depname: str, add_to: set[str]):
+            dep_info = self._search.find_provider(depname)
+
+            if dep_info is None:
+                raise ForeignPackageManagerError(
+                    f"Failed to find '{depname}' from AUR or user provided packages."
+                )
+
+            add_to.add(dep_info.pkgname)
+
+            output.print_debug(f"Adding dependency {dep_info.pkgname} to package {pkgname}.")
+            graph.add_requirement(dep_info.pkgname, pkgname)
+            if dep_info.pkgname not in seen_packages:
+                to_process.append(dep_info.pkgname)
+                seen_packages.add(dep_info.pkgname)
+
+        while to_process:
+            pkgname = to_process.pop()
+
+            info = self._search.get_package_info(pkgname)
+            if info is None:
+                raise ForeignPackageManagerError(
+                    f"Failed to find '{pkgname}' from AUR or user provided packages."
+                )
+
+            result.pacman_deps.update(info.native_dependencies(self._pacman))
+            result.add_pkgbase_info(pkgname, info.pkgbase)
+
+            build_deps = info.foreign_make_dependencies(
+                self._pacman
+            ) + info.foreign_check_dependencies(self._pacman)
+
+            self._search.try_caching_packages(info.foreign_dependencies(self._pacman) + build_deps)
+
+            for depname in info.foreign_dependencies(self._pacman):
+                process_dep(pkgname, depname, result.foreign_dep_pkgs)
+
+            for depname in build_deps:
+                process_dep(pkgname, depname, result.foreign_build_dep_pkgs)
+
+            total_processed += 1
+            output.print_info(f"Progress: {total_processed}/{len(seen_packages)}.")
+
+        output.print_info("Determining build order.")
+
+        while True:
+            to_add = graph.get_and_remove_outer_dep_pkgs()
+
+            if len(to_add) == 0:
+                break
+
+            for pkg in to_add:
+                if pkg not in result.packages:
+                    output.print_debug(f"Adding {pkg} to build_order.")
+                    result.build_order.append(pkg.name)
+                    result.packages[pkg.name] = pkg
+
+        return result
+
+    def should_upgrade_package(
+        self,
+        package: str,
+        installed_version: str,
+        fetched_version: str,
+        upgrade_devel=False,
+    ) -> bool:
+        """
+        Returns True if a package should be upgraded.
+        """
+
+        if upgrade_devel and is_devel(package):
+            output.print_debug(f"Package {package} is devel package. It should be upgraded.")
+            return True
+
+        try:
+            cmd = self._commands.compare_versions(installed_version, fetched_version)
+            vercmp_output = command.prg(cmd, pty=False)
+            should_upgrade = int(vercmp_output) < 0
+
+            output.print_debug(
+                f"Installed version is: {installed_version}. "
+                f"Available version is {fetched_version}. Should upgrade: {should_upgrade}."
+            )
+            return should_upgrade
+        except (ValueError, errors.CommandFailedError) as error:
+            output.print_error(f"{error}")
+            raise ForeignPackageManagerError("Failed to compare versions using vercmp.") from error
+
+
+class PackageBuilder:
+    """
+    Used for building packages in a chroot.
+    """
+
+    always_included_packages = ["base-devel", "git"]
+
+    def __init__(
+        self,
+        search: PackageSearch,
+        store: _store.Store,
+        pacman: AurPacmanInterface,
+        resolved_deps: ResolvedDependencies,
+        commands: AurCommands,
+        pkg_cache_dir: str,
+        build_dir: str,
+        makepkg_user: str,
+    ):
+        self._search = search
+        self._store = store
+        self._pacman = pacman
+        self._resolved_deps = resolved_deps
+        self._commands = commands
+        self.pkg_cache_dir = pkg_cache_dir
+        self.build_dir = build_dir
+        self.makepkg_user = makepkg_user
+        self.valid_pkgexts = [
+            ".pkg.tar",
+            ".pkg.tar.gz",
+            ".pkg.tar.bz2",
+            ".pkg.tar.xz",
+            ".pkg.tar.zst",
+            ".pkg.tar.lzo",
+            ".pkg.tar.lrz",
+            ".pkg.tar.lz4",
+            ".pkg.tar.lz",
+            ".pkg.tar.Z",
+        ]
+        self.chroot_wd_dir = os.path.join(build_dir, "chroot")
+        self.chroot_dir = os.path.join(self.chroot_wd_dir, "root")
+        self.pkgbase_dir_map: dict[str, str] = {}
+        self.original_wd = ""
+        self._pkgs_in_chroot = set(PackageBuilder.always_included_packages)
+        self._pkgs_in_chroot.update(resolved_deps.pacman_deps)
+
+    def __enter__(self):
+        self.store_wd()
+        self.create_build_environment()
+
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self.restore_wd()
+        self.remove_build_environment()
+
+    def store_wd(self):
+        """
+        Remembers the current working directory as the original working directory.
+        """
+        self.original_wd = os.getcwd()
+
+    def restore_wd(self):
+        """
+        Returns to the original working directory.
+        """
+        os.chdir(self.original_wd)
+
+    def create_build_environment(self):
+        """
+        Creates a new chroot and clones all PKGBUILDS.
+        """
+        output.print_info("Creating a build environment..")
+
+        if os.path.exists(self.build_dir):
+            output.print_info("Removing previous build directory.")
+            self.remove_build_environment()
+
+        output.print_info("Getting all PKGBUILDS.")
+
+        # Set up PKGBUILDS
+        for pkgbase in self._resolved_deps.all_pkgbases():
+            pkgbuild_dir = os.path.join(self.build_dir, pkgbase)
+            self.pkgbase_dir_map[pkgbase] = pkgbuild_dir
+            os.makedirs(pkgbuild_dir)
+            os.chdir(pkgbuild_dir)
+
+            pkgbase_info = self._search.get_package_info(
+                self._resolved_deps.get_some_pkgname(pkgbase)
+            )
+
+            assert pkgbase_info is not None, (
+                "All dependencies and packages should be resolved "
+                "during the creation of ResolvedDependencies."
+            )
+
+            output.print_debug(f"Git URL for '{pkgbase}' is '{pkgbase_info.git_url}'")
+            output.print_debug(
+                f"PKGBUILD directory for '{pkgbase}' is '{pkgbase_info.pkgbuild_directory}'"
+            )
+            self._fetch_and_review_pkgbuild(
+                pkgbase, pkgbase_info.git_url, pkgbase_info.pkgbuild_directory
+            )
+            shutil.chown(pkgbuild_dir, user=self.makepkg_user)
+
+        output.print_info("Creating a new chroot.")
+        os.makedirs(self.chroot_wd_dir)
+
+        # Remove GNUPGHOME from mkarchroot environment variables since it may interfere with
+        # the chroot creation
+        mkarchroot_env_vars = os.environ.copy()
+        try:
+            del mkarchroot_env_vars["GNUPGHOME"]
+            output.print_debug("Removed GNUPGHOME variable from mkarchroot environment.")
+        except KeyError:
+            pass
+
+        cmd = self._commands.make_chroot(self.chroot_dir, self._pkgs_in_chroot)
+        command.prg(
+            cmd, env_overrides=mkarchroot_env_vars, pass_environment=False, pty=config.debug_output
+        )
+
+    def remove_build_environment(self):
+        """
+        Deletes the build environment.
+        """
+        shutil.rmtree(self.build_dir)
+
+    def build_packages(self, package_base: str, packages: list[ForeignPackage], force: bool):
+        """
+        Builds package(s) with the same package base.
+
+        Set force to true to force rebuilds of packages that are already cached
+        """
+
+        package_names = list(map(lambda p: p.name, packages))
+
+        # Rebuild is only needed if at least one package is not in the cache.
+
+        if self._are_all_pkgs_cached(packages) and not force:
+            output.print_info(f"Skipped building '{' '.join(package_names)}'. Already up to date.")
+            return
+
+        output.print_info(f"Building '{' '.join(package_names)}'.")
+
+        chroot_new_pacman_pkgs, chroot_pkg_files = self._get_chroot_packages(packages)
+
+        pkgbuild_dir = self.pkgbase_dir_map[package_base]
+        os.chdir(pkgbuild_dir)
+
+        output.print_debug(f"Chroot dir is: '{self.chroot_dir}', pkgbuild dir is '{pkgbuild_dir}'.")
+
+        output.print_info("Installing build dependencies to chroot.")
+
+        cmd = self._commands.install_chroot(
+            self.chroot_dir, chroot_new_pacman_pkgs + PackageBuilder.always_included_packages
+        )
+        command.prg(cmd, pty=config.debug_output)
+        output.print_info("Making package.")
+
+        cmd = self._commands.make_chroot_pkg(
+            self.chroot_wd_dir, self.makepkg_user, chroot_pkg_files
+        )
+        command.prg(cmd)
+
+        for pkgname in package_names:
+            file = self._find_pkgfile(pkgname, pkgbuild_dir)
+
+            dest = shutil.copy(file, self.pkg_cache_dir)
+
+            pkg_info = self._search.get_package_info(pkgname)
+
+            # Because all dependencies and packages should be resolved during the creation
+            # of ResolvedDependencies.
+            assert pkg_info is not None
+            version = pkg_info.version
+
+            output.print_debug(
+                f"Adding '{pkgname}', version: '{version}' to cache as file '{dest}'."
+            )
+
+            add_package_to_cache(self._store, pkgname, version, dest)
+
+        output.print_info("Removing build dependencies from chroot.")
+
+        if len(chroot_new_pacman_pkgs) != 0:
+            to_remove = set()
+            for p in chroot_new_pacman_pkgs:
+                if p not in self._pkgs_in_chroot:
+                    cmd = self._commands.resolve_real_name_chroot(self.chroot_dir, p)
+                    _, cmd_output = command.check_run_result(cmd, command.run(cmd))
+                    real_pkgname = cmd_output.strip()
+                    to_remove.add(real_pkgname)
+            cmd = self._commands.remove_chroot(self.chroot_dir, to_remove)
+            command.prg(cmd, pty=config.debug_output)
+
+        output.print_info(f"Finished building: '{' '.join(package_names)}'.")
+
+    def _are_all_pkgs_cached(self, pkgs: list[ForeignPackage]) -> bool:
+        for pkg in pkgs:
+            cache_entry = find_latest_cached_package(self._store, pkg.name)
+            if cache_entry is None:
+                return False
+            cached_version, _ = cache_entry
+
+            pkg_info = self._search.get_package_info(pkg.name)
+
+            # Because all dependencies and packages should be resolved during the creation
+            # of ResolvedDependencies. git_url should not be None.
+            assert pkg_info is not None
+            fetched_version = pkg_info.version
+
+            if cached_version != fetched_version or is_devel(pkg.name):
+                return False
+        return True
+
+    def _get_chroot_packages(
+        self, pkgs_to_build: list[ForeignPackage]
+    ) -> tuple[list[str], list[str]]:
+        """
+        Returns a tuple of pacman build dependencies and built foreign pkgs files that are needed
+        in the chroot before building. pkgs_to_build share the same pkgbase.
+        """
+        chroot_pacman_build_deps = set()
+        chroot_foreign_pkgs = set()
+
+        def add_to_pacman_build_deps(deps: list[str]):
+            for dep in deps:
+                if dep not in self._resolved_deps.pacman_deps:
+                    chroot_pacman_build_deps.add(dep)
+
+        for pkg in pkgs_to_build:
+            info = self._search.get_package_info(pkg.name)
+            # Because all dependencies and packages should be resolved during the creation
+            # of ResolvedDependencies. git_url should not be None.
+            assert info is not None
+
+            add_to_pacman_build_deps(info.native_make_dependencies(self._pacman))
+            add_to_pacman_build_deps(info.native_check_dependencies(self._pacman))
+
+            foreign_deps = pkg.get_all_recursive_foreign_dep_pkgs()
+            chroot_foreign_pkgs.update(foreign_deps)
+
+            # Add pacman deps of foreign packages
+            for dep in foreign_deps:
+                dep_info = self._search.get_package_info(dep)
+                # Because all dependencies and packages should be resolved during the creation
+                # of ResolvedDependencies. git_url should not be None.
+                assert dep_info is not None
+
+                add_to_pacman_build_deps(dep_info.native_make_dependencies(self._pacman))
+                add_to_pacman_build_deps(dep_info.native_check_dependencies(self._pacman))
+
+        # Packages with the same pkgbase might depend on each other,
+        # but they don't need to be installed for the build to succeed.
+        for pkg in pkgs_to_build:
+            if pkg.name in chroot_foreign_pkgs:
+                chroot_foreign_pkgs.remove(pkg.name)
+
+        chroot_foreign_pkg_files = []
+
+        for foreign_pkg in chroot_foreign_pkgs:
+            entry = find_latest_cached_package(self._store, foreign_pkg)
+            assert entry is not None, (
+                "Build order determines that the dependencies are built "
+                "before and thus are found in the cache."
+            )
+
+            _, file = entry
+
+            chroot_foreign_pkg_files.append(file)
+
+        return (list(chroot_pacman_build_deps), chroot_foreign_pkg_files)
+
+    def _find_pkgfile(self, pkgname: str, pkgbuild_dir: str) -> str:
+        # HACK: Because we don't know the pkgarch we can't be sure what is the build result.
+        # Instead: we just try with pre- and postfixes.
+
+        matches = []
+
+        info = self._search.get_package_info(pkgname)
+        assert info is not None
+        prefix = info.pkg_file_prefix()
+
+        for file in os.scandir(pkgbuild_dir):
+            if file.is_file() and file.name.startswith(prefix):
+                for ext in self.valid_pkgexts:
+                    if file.name.endswith(ext):
+                        matches.append(file.path)
+                        continue
+
+        if len(matches) != 1:
+            raise ForeignPackageManagerError(
+                f"Failed to build package '{pkgname}', because the pkg file cannot be determined. "
+                f"Possible files are: {matches}"
+            )
+
+        return matches[0]
+
+    def _fetch_and_review_pkgbuild(
+        self, pkgbase: str, git_url: str | None, pkgbuild_directory: str | None
+    ):
+        """
+        Fetches a PKGBUILD to the current directory.
+
+        PKGBUILD will be cloned using git if ``git_url`` is set.
+        PKGBUILD will be copied from ``pkgbuild_directory`` if it is set.
+
+        The user is prompted to review the PKGBUILD and confirm if the package should be built.
+        """
+
+        self._store.ensure("pkgbuild_latest_reviewed_commits", {})
+
+        if git_url:
+            cmd = self._commands.git_clone(git_url, ".")
+            command.prg(cmd, pty=config.debug_output)
+
+        if pkgbuild_directory:
+            try:
+                shutil.copytree(pkgbuild_directory, ".", dirs_exist_ok=True)
+
+                # Chmod to 755 to allow reading files
+                mode = 0o755
+                for root, dirs, files in os.walk("."):
+                    for name in dirs + files:
+                        os.chmod(os.path.join(root, name), mode)
+                os.chmod(".", mode)
+            except OSError as error:
+                raise ForeignPackageManagerError(f"Failed to copy {pkgbuild_directory}.") from error
+
+        if output.prompt_confirm(f"Review PKGBUILD or show diff for {pkgbase}?", default=True):
+            latest_reviewed_commit = None
+            git_commit_ids = []
+
+            if git_url:
+                latest_reviewed_commit = self._store["pkgbuild_latest_reviewed_commits"].get(
+                    pkgbase
+                )
+
+                cmd = self._commands.git_log_commit_ids()
+                git_output = command.prg(cmd, pty=False)
+                git_commit_ids = git_output.strip().split("\n")
+
+            if latest_reviewed_commit is None or latest_reviewed_commit not in git_commit_ids:
+                try:
+                    for file in os.scandir("."):
+                        if file.is_file() and not file.name.startswith("."):
+                            cmd = self._commands.review_file(file.path)
+                            command.prg(cmd)
+                except OSError as error:
+                    raise ForeignPackageManagerError(
+                        f"Failed to review files in directory for {pkgbase}."
+                    ) from error
+
+            else:
+                cmd = self._commands.git_diff(latest_reviewed_commit)
+                command.prg(cmd)
+
+        if output.prompt_confirm("Build this package?", default=True):
+            cmd = self._commands.git_get_commit_id()
+            rc, git_output = command.run(cmd)
+            if rc == 0:
+                commit_id = git_output.strip()
+                self._store["pkgbuild_latest_reviewed_commits"][pkgbase] = commit_id
+            else:
+                output.print_debug(
+                    f"{pkgbase} is not in a git repository. Commit ID cannot be saved."
+                )
+        else:
+            raise ForeignPackageManagerError("Building aborted.")

plugins/decman-pacman/src/decman/plugins/aur/package.py

@@ -0,0 +1,714 @@
+import dataclasses
+import os
+import pathlib
+import shutil
+import tempfile
+
+import decman.plugins.pacman as pacman_module
+import requests  # type: ignore
+from decman.plugins.aur.commands import AurCommands, AurPacmanInterface
+from decman.plugins.aur.error import AurRPCError, PKGBUILDParseError
+
+import decman.config as config
+import decman.core.command as command
+import decman.core.error as errors
+import decman.core.output as output
+
+
+@dataclasses.dataclass(frozen=True, slots=True)
+class PackageInfo:
+    """
+    Immutable description of a package to be built or installed.
+
+    This class represents *resolved* package metadata and is intended to be
+    passed around as pure data.
+
+    Exactly one source must be specified:
+    - ``git_url`` for VCS-based (e.g. AUR) packages
+    - ``pkgbuild_directory`` for local PKGBUILD-based packages
+
+    Invariants:
+    - ``pkgname`` uniquely identifies the package.
+    - ``pkgbase`` groups split packages.
+    - Exactly one of ``git_url`` or ``pkgbuild_directory`` is set.
+    - All dependency containers are immutable.
+
+    This object is safe for hashing, set membership, and reuse across runs.
+    """
+
+    pkgname: str
+    pkgbase: str
+    version: str
+
+    git_url: str | None = None
+    pkgbuild_directory: str | None = None
+    provides: tuple[str, ...] = dataclasses.field(default_factory=tuple)
+    dependencies: tuple[str, ...] = dataclasses.field(default_factory=tuple)
+    make_dependencies: tuple[str, ...] = dataclasses.field(default_factory=tuple)
+    check_dependencies: tuple[str, ...] = dataclasses.field(default_factory=tuple)
+
+    # Caches (excluded from eq/hash)
+    _native_dependencies: tuple[str, ...] | None = dataclasses.field(
+        default=None, init=False, repr=False, compare=False
+    )
+    _foreign_dependencies: tuple[str, ...] | None = dataclasses.field(
+        default=None, init=False, repr=False, compare=False
+    )
+
+    _native_make_dependencies: tuple[str, ...] | None = dataclasses.field(
+        default=None, init=False, repr=False, compare=False
+    )
+    _foreign_make_dependencies: tuple[str, ...] | None = dataclasses.field(
+        default=None, init=False, repr=False, compare=False
+    )
+
+    _native_check_dependencies: tuple[str, ...] | None = dataclasses.field(
+        default=None, init=False, repr=False, compare=False
+    )
+    _foreign_check_dependencies: tuple[str, ...] | None = dataclasses.field(
+        default=None, init=False, repr=False, compare=False
+    )
+
+    def __post_init__(self) -> None:
+        if self.git_url is None and self.pkgbuild_directory is None:
+            raise ValueError("Both git_url and pkgbuild_directory cannot be None.")
+
+        if self.git_url is not None and self.pkgbuild_directory is not None:
+            raise ValueError("Both git_url and pkgbuild_directory cannot be set.")
+
+    def pkg_file_prefix(self) -> str:
+        """
+        Returns the beginning of the file created from building this package.
+        """
+        return f"{self.pkgname}-{self.version}"
+
+    # --- public API ---------------------------------------------------------
+
+    def foreign_dependencies(self, pacman: AurPacmanInterface) -> list[str]:
+        """
+        Returns a list of foreign dependencies of this package.
+
+        The dependencies are stripped of their version constraints if there are any.
+        """
+        self._ensure_dependencies_cached(pacman)
+        assert self._foreign_dependencies is not None
+        return list(self._foreign_dependencies)
+
+    def foreign_make_dependencies(self, pacman: AurPacmanInterface) -> list[str]:
+        """
+        Returns a list of foreign make dependencies of this package.
+
+        The dependencies are stripped of their version constraints if there are any.
+        """
+        self._ensure_make_dependencies_cached(pacman)
+        assert self._foreign_make_dependencies is not None
+        return list(self._foreign_make_dependencies)
+
+    def foreign_check_dependencies(self, pacman: AurPacmanInterface) -> list[str]:
+        """
+        Returns a list of foreign check dependencies of this package.
+
+        The dependencies are stripped of their version constraints if there are any.
+        """
+        self._ensure_check_dependencies_cached(pacman)
+        assert self._foreign_check_dependencies is not None
+        return list(self._foreign_check_dependencies)
+
+    def native_dependencies(self, pacman: AurPacmanInterface) -> list[str]:
+        """
+        Returns a list of native dependencies of this package.
+
+        The dependencies are stripped of their version constraints if there are any.
+        """
+        self._ensure_dependencies_cached(pacman)
+        assert self._native_dependencies is not None
+        return list(self._native_dependencies)
+
+    def native_make_dependencies(self, pacman: AurPacmanInterface) -> list[str]:
+        """
+        Returns a list of native make dependencies of this package.
+
+        The dependencies are stripped of their version constraints if there are any.
+        """
+        self._ensure_make_dependencies_cached(pacman)
+        assert self._native_make_dependencies is not None
+        return list(self._native_make_dependencies)
+
+    def native_check_dependencies(self, pacman: AurPacmanInterface) -> list[str]:
+        """
+        Returns a list of native check dependencies of this package.
+
+        The dependencies are stripped of their version constraints if there are any.
+        """
+        self._ensure_check_dependencies_cached(pacman)
+        assert self._native_check_dependencies is not None
+        return list(self._native_check_dependencies)
+
+    # --- internal helpers ---------------------------------------------------
+
+    @staticmethod
+    def _classify_dependencies(
+        deps: tuple[str, ...], pacman: AurPacmanInterface
+    ) -> tuple[tuple[str, ...], tuple[str, ...]]:
+        native: list[str] = []
+        foreign: list[str] = []
+
+        for dependency in deps:
+            stripped = pacman_module.strip_dependency(dependency)
+            if pacman.is_installable(dependency):
+                native.append(stripped)
+            else:
+                foreign.append(stripped)
+
+        return tuple(native), tuple(foreign)
+
+    def _ensure_dependencies_cached(self, pacman: AurPacmanInterface) -> None:
+        if self._native_dependencies is not None:
+            return
+
+        native, foreign = self._classify_dependencies(self.dependencies, pacman)
+        object.__setattr__(self, "_native_dependencies", native)
+        object.__setattr__(self, "_foreign_dependencies", foreign)
+
+    def _ensure_make_dependencies_cached(self, pacman: AurPacmanInterface) -> None:
+        if self._native_make_dependencies is not None:
+            return
+
+        native, foreign = self._classify_dependencies(self.make_dependencies, pacman)
+        object.__setattr__(self, "_native_make_dependencies", native)
+        object.__setattr__(self, "_foreign_make_dependencies", foreign)
+
+    def _ensure_check_dependencies_cached(self, pacman: AurPacmanInterface) -> None:
+        if self._native_check_dependencies is not None:
+            return
+
+        native, foreign = self._classify_dependencies(self.check_dependencies, pacman)
+        object.__setattr__(self, "_native_check_dependencies", native)
+        object.__setattr__(self, "_foreign_check_dependencies", foreign)
+
+
+class CustomPackage:
+    """
+    Custom package installed from some other location than the official repos or the AUR.
+
+    ``pkgname`` is required because the PKGBUILD might be for split packages.
+
+    Exactly one of ``git_url`` or ``pkgbuild_directory`` must be provided.
+
+    Parameters:
+        ``pkgname``:
+            Name of the package.
+
+        ``git_url``:
+            URL to a git repository containing the PKGBUILD.
+
+        ``pkgbuild_directory``:
+            Path to the directory containing the PKGBUILD.
+    """
+
+    def __init__(
+        self, pkgname: str, git_url: str | None = None, pkgbuild_directory: str | None = None
+    ) -> None:
+        if git_url is None and pkgbuild_directory is None:
+            raise ValueError("Both git_url and pkgbuild_directory cannot be None.")
+
+        if git_url is not None and pkgbuild_directory is not None:
+            raise ValueError("Both git_url and pkgbuild_directory cannot be set.")
+
+        self.pkgname = pkgname
+        self.git_url = git_url
+        self.pkgbuild_directory = pkgbuild_directory
+
+    def parse(self, commands: AurCommands) -> PackageInfo:
+        """
+        Parses this package's PKGBUILD to ``PackageInfo``.
+
+        If this fails, raises a ``PKGBUILDParseError``.
+        """
+        if self.pkgbuild_directory is not None:
+            srcinfo = self._srcinfo_from_pkgbuild_directory(commands)
+        else:
+            srcinfo = self._srcinfo_from_git(commands)
+
+        return self._parse_srcinfo(srcinfo)
+
+    def __eq__(self, other: object) -> bool:
+        if not isinstance(other, CustomPackage):
+            return False
+        return (
+            self.git_url == other.git_url
+            and self.pkgbuild_directory == other.pkgbuild_directory
+            and self.pkgname == other.pkgname
+        )
+
+    def __hash__(self) -> int:
+        return hash((self.pkgname, self.git_url, self.pkgbuild_directory))
+
+    def __str__(self) -> str:
+        if self.git_url is not None:
+            return f"CustomPackage(pkgname={self.pkgname}, git_url={self.git_url})"
+        return (
+            f"CustomPackage(pkgname={self.pkgname}, pkgbuild_directory={self.pkgbuild_directory})"
+        )
+
+    def _srcinfo_from_pkgbuild_directory(self, commands: AurCommands) -> str:
+        assert self.pkgbuild_directory is not None, (
+            "This will not get called if pkgbuild_directory is unset."
+        )
+
+        path = pathlib.Path(self.pkgbuild_directory)
+        if not path.is_dir():
+            raise PKGBUILDParseError(
+                self.git_url,
+                self.pkgbuild_directory,
+                f"pkgbuild_directory '{path}' does not exist or is not a directory.",
+            )
+
+        if not (path / "PKGBUILD").exists():
+            raise PKGBUILDParseError(
+                self.git_url, self.pkgbuild_directory, f"No PKGBUILD found in '{path}'."
+            )
+
+        try:
+            with tempfile.TemporaryDirectory(prefix="decman-pkgbuild-") as tmpdir:
+                tmp_path = pathlib.Path(tmpdir)
+                # Allow the user 'nobody' to use this directory
+                os.chmod(tmpdir, 0o777)
+                shutil.copy(path / "PKGBUILD", tmp_path / "PKGBUILD")
+                os.chmod(tmp_path / "PKGBUILD", 0o644)
+
+                return self._run_makepkg_printsrcinfo(tmp_path, commands)
+        except OSError as error:
+            raise PKGBUILDParseError(
+                self.git_url,
+                self.pkgbuild_directory,
+                "Failed to create temporary directory for the PKGBUILD.",
+            ) from error
+
+    def _srcinfo_from_git(self, commands: AurCommands) -> str:
+        assert self.git_url is not None, "This will not get called if git_url is unset."
+        try:
+            with tempfile.TemporaryDirectory(prefix="decman-pkgbuild-") as tmpdir:
+                tmp_path = pathlib.Path(tmpdir)
+                # Allow the user 'nobody' to use this directory
+                os.chmod(tmpdir, 0o777)
+                try:
+                    cmd = commands.git_clone(self.git_url, tmpdir)
+                    # Use the user nobody, since that will be used later to generate SRCINFO
+                    command.prg(cmd, user="nobody", pty=config.debug_output)
+                except errors.CommandFailedError as error:
+                    raise PKGBUILDParseError(
+                        self.git_url,
+                        self.pkgbuild_directory,
+                        "Failed to clone PKGBUILD repository.",
+                    ) from error
+
+                if not (tmp_path / "PKGBUILD").exists():
+                    raise PKGBUILDParseError(
+                        self.git_url,
+                        self.pkgbuild_directory,
+                        f"Cloned repository '{self.git_url}' does not contain a PKGBUILD.",
+                    )
+
+                return self._run_makepkg_printsrcinfo(tmp_path, commands)
+        except OSError as error:
+            raise PKGBUILDParseError(
+                self.git_url,
+                self.pkgbuild_directory,
+                "Failed to create temporary directory for the PKGBUILD.",
+            ) from error
+
+    def _run_makepkg_printsrcinfo(self, path: pathlib.Path, commands: AurCommands) -> str:
+        orig_wd = os.getcwd()
+        try:
+            os.chdir(path)
+            cmd = commands.print_srcinfo()
+            # No need to use the makepkg_user config option here.
+            # For just printing the SRCINFO, hardcoded 'nobody' works
+            srcinfo = command.prg(cmd, user="nobody", pty=False)
+        except errors.CommandFailedError as error:
+            raise PKGBUILDParseError(
+                self.git_url, self.pkgbuild_directory, "Failed to generate SRCINFO using makepkg."
+            ) from error
+        finally:
+            os.chdir(orig_wd)
+
+        return srcinfo
+
+    def _parse_srcinfo(self, srcinfo: str) -> PackageInfo:
+        pkgbase: str | None = None
+        pkgver: str | None = None
+        pkgrel: str | None = None
+        epoch: str | None = None
+        provides: list[str] = []
+
+        # I'm not sure if split packages can have dependencies listed in the base.
+        # Easy to handle regardless
+        base_depends: list[str] = []
+        base_makedepends: list[str] = []
+        base_checkdepends: list[str] = []
+
+        pkg_depends: list[str] = []
+        pkg_makedepends: list[str] = []
+        pkg_checkdepends: list[str] = []
+
+        current_pkg: str | None = None
+        found_pkgnames = set()
+
+        for raw in srcinfo.splitlines():
+            line = raw.strip()
+            if not line or line.startswith("#") or "=" not in line:
+                continue
+
+            key, value = (part.strip() for part in line.split("=", 1))
+
+            is_base = current_pkg is None
+            is_target_pkg = current_pkg == self.pkgname
+
+            match key:
+                case "pkgbase":
+                    pkgbase = value
+                    current_pkg = None
+
+                case "pkgname":
+                    current_pkg = value
+                    found_pkgnames.add(value)
+
+                case "pkgver":
+                    if pkgver is None or current_pkg == self.pkgname:
+                        pkgver = value
+
+                case "pkgrel":
+                    if pkgrel is None or current_pkg == self.pkgname:
+                        pkgrel = value
+
+                case "epoch":
+                    if epoch is None or current_pkg == self.pkgname:
+                        epoch = value
+
+                case "provides":
+                    if is_target_pkg:
+                        provides.append(value)
+
+                case "depends":
+                    if is_base:
+                        base_depends.append(value)
+                    elif is_target_pkg:
+                        pkg_depends.append(value)
+
+                case "makedepends":
+                    if is_base:
+                        base_makedepends.append(value)
+                    elif is_target_pkg:
+                        pkg_makedepends.append(value)
+
+                case "checkdepends":
+                    if is_base:
+                        base_checkdepends.append(value)
+                    elif is_target_pkg:
+                        pkg_checkdepends.append(value)
+
+                case _ if key.startswith("depends") and key.removeprefix("depends_") == config.arch:
+                    if is_base:
+                        base_depends.append(value)
+                    elif is_target_pkg:
+                        pkg_depends.append(value)
+
+                case _ if (
+                    key.startswith("makedepends")
+                    and key.removeprefix("makedepends_") == config.arch
+                ):
+                    if is_base:
+                        base_makedepends.append(value)
+                    elif is_target_pkg:
+                        pkg_makedepends.append(value)
+
+                case _ if (
+                    key.startswith("checkdepends")
+                    and key.removeprefix("checkdepends_") == config.arch
+                ):
+                    if is_base:
+                        base_checkdepends.append(value)
+                    elif is_target_pkg:
+                        pkg_checkdepends.append(value)
+
+        if pkgbase is None or pkgver is None:
+            raise PKGBUILDParseError(
+                self.git_url,
+                self.pkgbuild_directory,
+                "Missing required fields (pkgbase/pkgver) in SRCINFO.",
+            )
+
+        if self.pkgname not in found_pkgnames:
+            raise PKGBUILDParseError(
+                self.git_url,
+                self.pkgbuild_directory,
+                f"Package {self.pkgname} not found in SRCINFO. "
+                f"Packages present: {' '.join(found_pkgnames)}.",
+            )
+
+        version_core = pkgver
+        if pkgrel is not None:
+            version_core = f"{version_core}-{pkgrel}"
+
+        if epoch is not None:
+            version = f"{epoch}:{version_core}"
+        else:
+            version = version_core
+
+        return PackageInfo(
+            pkgname=self.pkgname,
+            pkgbase=pkgbase,
+            version=version,
+            git_url=self.git_url,
+            pkgbuild_directory=self.pkgbuild_directory,
+            provides=tuple(provides),
+            dependencies=tuple(base_depends + pkg_depends),
+            make_dependencies=tuple(base_makedepends + pkg_makedepends),
+            check_dependencies=tuple(base_checkdepends + pkg_checkdepends),
+        )
+
+
+class PackageSearch:
+    """
+    Allows searcing for packages / providers from the AUR as well as user defined sources.
+
+    Results are cached and custom packages are preferred.
+    """
+
+    def __init__(self, aur_rpc_timeout: int = 30) -> None:
+        self._package_cache: dict[str, PackageInfo] = {}
+        self._selected_providers_cache: dict[str, PackageInfo] = {}
+        self._all_providers_cache: dict[str, list[str]] = {}
+        self._custom_packages: list[PackageInfo] = []
+        self._timeout = aur_rpc_timeout
+
+    def add_custom_pkg(self, user_pkg: PackageInfo):
+        """
+        Adds the given package to custom packages.
+        """
+        self._custom_packages.append(user_pkg)
+        self._cache_pkg(user_pkg)
+
+    def _cache_pkg(self, pkg: PackageInfo):
+        for provided_pkg in pkg.provides:
+            self._all_providers_cache.setdefault(provided_pkg, []).append(pkg.pkgname)
+
+        self._package_cache[pkg.pkgname] = pkg
+
+    def try_caching_packages(self, packages: list[str]):
+        """
+        Tries caching the given packages. Virtual packages may not be cached.
+
+        This can be used before calling get_package_info or find_provider multiple individual
+        times, because then those methods don't have to make new AUR RPC requests.
+        """
+
+        uncached_packages = list(filter(lambda p: p not in self._package_cache, packages))
+
+        if len(uncached_packages) == 0:
+            return
+
+        output.print_debug(f"Trying to cache {uncached_packages}.")
+
+        max_pkgs_per_request = 200
+
+        while uncached_packages:
+            to_request = map(lambda p: f"arg[]={p}", uncached_packages[:max_pkgs_per_request])
+            uncached_packages = uncached_packages[max_pkgs_per_request:]
+
+            url = f"https://aur.archlinux.org/rpc/v5/info?{'&'.join(to_request)}"
+            output.print_debug(f"Request URL = {url}")
+
+            try:
+                request = requests.get(url, timeout=self._timeout)
+                d = request.json()
+
+                if d["type"] == "error":
+                    raise AurRPCError(f"AUR RPC returned error: {d['error']}", url)
+
+                for result in d["results"]:
+                    pkgname = result["Name"]
+
+                    if pkgname in self._package_cache:
+                        continue
+
+                    for user_package in self._custom_packages:
+                        if user_package.pkgname == pkgname:
+                            output.print_debug(f"'{pkgname}' found in custom packages.")
+                            self._cache_pkg(user_package)
+                            break
+                    else:  # if not in user_packages then:
+                        info = PackageInfo(
+                            pkgname=result["Name"],
+                            pkgbase=result["PackageBase"],
+                            version=result["Version"],
+                            dependencies=result.get("Depends", []),
+                            make_dependencies=result.get("MakeDepends", []),
+                            check_dependencies=result.get("CheckDepends", []),
+                            provides=result.get("Provides", []),
+                            git_url=f"https://aur.archlinux.org/{result['PackageBase']}.git",
+                        )
+                        self._cache_pkg(info)
+
+                output.print_debug("Request completed.")
+            except (requests.RequestException, KeyError) as e:
+                raise AurRPCError(
+                    f"Failed to fetch package information for {uncached_packages} from AUR RPC.",
+                    url,
+                ) from e
+
+    def get_package_info(self, package: str) -> PackageInfo | None:
+        """
+        Returns information about a package.
+
+        If the package is not custom, fetches information from the AUR.
+        Returns None if no such AUR package exists.
+        """
+        output.print_debug(f"Getting info for package '{package}'.")
+
+        if package in self._package_cache:
+            output.print_debug(f"'{package}' found in cache.")
+            return self._package_cache[package]
+
+        # This code is probably not needed since all user packages should be cached
+        for user_package in self._custom_packages:
+            if user_package.pkgname == package:
+                output.print_debug(f"'{package}' found in custom packages.")
+                self._cache_pkg(user_package)
+                return user_package
+
+        url = f"https://aur.archlinux.org/rpc/v5/info/{package}"
+        output.print_debug(f"Requesting info for '{package}' from AUR. URL = {url}")
+        try:
+            request = requests.get(url, timeout=self._timeout)
+            d = request.json()
+
+            if d["type"] == "error":
+                raise AurRPCError(f"AUR RPC returned error: {d['error']}", url)
+
+            if d["resultcount"] == 0:
+                output.print_debug(f"'{package}' not found.")
+                return None
+
+            output.print_debug(f"'{package}' found from AUR.")
+
+            result = d["results"][0]
+            info = PackageInfo(
+                pkgname=result["Name"],
+                pkgbase=result["PackageBase"],
+                version=result["Version"],
+                dependencies=result.get("Depends", []),
+                make_dependencies=result.get("MakeDepends", []),
+                check_dependencies=result.get("CheckDepends", []),
+                provides=result.get("Provides", []),
+                git_url=f"https://aur.archlinux.org/{result['PackageBase']}.git",
+            )
+
+            self._cache_pkg(info)
+
+            return info
+        except (requests.RequestException, KeyError) as e:
+            raise AurRPCError(
+                f"Failed to fetch package information for {package} from AUR RPC.",
+                url,
+            ) from e
+
+    def find_provider(self, stripped_dependency: str) -> PackageInfo | None:
+        """
+        Finds a provider for a dependency. The dependency should not contain version constraints.
+
+        May prompt the user to select if multiple are available.
+        """
+        output.print_debug(f"Finding provider for '{stripped_dependency}'.")
+
+        if stripped_dependency in self._selected_providers_cache:
+            output.print_debug(f"'{stripped_dependency}' found in cache.")
+            return self._selected_providers_cache[stripped_dependency]
+
+        output.print_debug("Are there exact name matches?")
+
+        exact_name_match = self.get_package_info(stripped_dependency)
+
+        if exact_name_match is not None:
+            output.print_debug("Exact name match found.")
+            self._selected_providers_cache[stripped_dependency] = exact_name_match
+            return exact_name_match
+
+        output.print_debug("No exact name matches found. Finding providers.")
+
+        known_pkg_results = self._all_providers_cache.get(stripped_dependency, [])
+        for user_package in self._custom_packages:
+            if (
+                stripped_dependency in user_package.provides
+                and stripped_dependency not in known_pkg_results
+            ):
+                known_pkg_results.append(user_package.pkgname)
+
+        if len(known_pkg_results) == 1:
+            pkg = self.get_package_info(known_pkg_results[0])
+            assert pkg is not None
+            output.print_debug(
+                f"Single provider for '{stripped_dependency}' found in known packages: '{pkg}'."
+            )
+            self._selected_providers_cache[stripped_dependency] = pkg
+            return pkg
+
+        if len(known_pkg_results) > 1:
+            return self._choose_provider(stripped_dependency, known_pkg_results, "user packages")
+
+        url = f"https://aur.archlinux.org/rpc/v5/search/{stripped_dependency}?by=provides"
+        output.print_debug(
+            f"Requesting providers for '{stripped_dependency}' from AUR. URL = {url}"
+        )
+        try:
+            request = requests.get(url, timeout=self._timeout)
+            d = request.json()
+
+            if d["type"] == "error":
+                raise AurRPCError(f"AUR RPC returned error: {d['error']}", url)
+
+            if d["resultcount"] == 0:
+                output.print_debug(f"'{stripped_dependency}' not found.")
+                return None
+
+            results = list(map(lambda r: r["Name"], d["results"]))
+
+            if len(results) == 1:
+                pkgname = results[0]
+                output.print_debug(
+                    f"Single provider for '{stripped_dependency}' found from AUR: '{pkgname}'"
+                )
+                info = self.get_package_info(pkgname)
+                return info
+
+            return self._choose_provider(stripped_dependency, results, "AUR")
+        except (requests.RequestException, KeyError) as e:
+            raise AurRPCError(
+                f"Failed to search for {stripped_dependency} from AUR RPC.",
+                url,
+            ) from e
+
+    def _choose_provider(
+        self, dep: str, possible_providers: list[str], where: str
+    ) -> PackageInfo | None:
+        min_selection = 1
+        max_selection = len(possible_providers)
+        output.print_summary(f"Found {len(possible_providers)} providers for {dep} from {where}.")
+
+        providers = "Providers: "
+        for index, name in enumerate(possible_providers):
+            providers += f"{index + 1}:{name} "
+        output.print_summary(providers)
+
+        selection = output.prompt_number(
+            f"Select a provider [{min_selection}-{max_selection}] (default: {min_selection}): ",
+            min_selection,
+            max_selection,
+            default=min_selection,
+        )
+
+        info = self.get_package_info(possible_providers[selection - 1])
+        if info is not None:
+            self._selected_providers_cache[dep] = info
+        return info

plugins/decman-pacman/src/decman/plugins/aur/resolver.py

@@ -0,0 +1,119 @@
+import typing
+
+from decman.plugins.aur.error import DependencyCycleError
+
+
+class ForeignPackage:
+    """
+    Class used to keep track of foreign recursive dependency packages of an foreign package.
+    """
+
+    def __init__(self, name: str):
+        self.name = name
+        self._all_recursive_foreign_deps: set[str] = set()
+
+    def __eq__(self, value: object, /) -> bool:
+        if isinstance(value, self.__class__):
+            return (
+                self.name == value.name
+                and self._all_recursive_foreign_deps == value._all_recursive_foreign_deps
+            )
+        return False
+
+    def __hash__(self) -> int:
+        return self.name.__hash__()
+
+    def __repr__(self) -> str:
+        return f"{self.name}: {{{' '.join(self._all_recursive_foreign_deps)}}}"
+
+    def __str__(self) -> str:
+        return f"{self.name}"
+
+    def add_foreign_dependency_packages(self, package_names: typing.Iterable[str]):
+        """
+        Adds dependencies to the package.
+        """
+        self._all_recursive_foreign_deps.update(package_names)
+
+    def get_all_recursive_foreign_dep_pkgs(self) -> set[str]:
+        """
+        Returns all dependencies and sub-dependencies of the package.
+        """
+        return set(self._all_recursive_foreign_deps)
+
+
+class DepNode:
+    """
+    A Node of the DepGraph
+    """
+
+    def __init__(self, package: ForeignPackage) -> None:
+        self.parents: dict[str, DepNode] = {}
+        self.children: dict[str, DepNode] = {}
+        self.pkg = package
+
+    def is_pkgname_in_parents_recursive(self, pkgname: str) -> bool:
+        """
+        Returns True if the given package name is in the parents of this DepNode.
+        """
+        for name, parent in self.parents.items():
+            if name == pkgname or parent.is_pkgname_in_parents_recursive(pkgname):
+                return True
+        return False
+
+
+class DepGraph:
+    """
+    Represents a graph between foreign packages
+    """
+
+    def __init__(self) -> None:
+        self.package_nodes: dict[str, DepNode] = {}
+        self._childless_node_names: set[str] = set()
+
+    def add_requirement(self, child_pkgname: str, parent_pkgname: typing.Optional[str]):
+        """
+        Adds a connection between two packages, creating the child package if it doesn't exist.
+
+        The parent is the package that requires the child package.
+        """
+        child_node = self.package_nodes.get(child_pkgname, DepNode(ForeignPackage(child_pkgname)))
+        self.package_nodes[child_pkgname] = child_node
+
+        if len(child_node.children) == 0:
+            self._childless_node_names.add(child_pkgname)
+
+        if parent_pkgname is None:
+            return
+
+        parent_node = self.package_nodes[parent_pkgname]
+
+        if parent_node.is_pkgname_in_parents_recursive(child_pkgname):
+            raise DependencyCycleError(child_pkgname, parent_pkgname)
+
+        parent_node.children[child_pkgname] = child_node
+        child_node.parents[parent_pkgname] = parent_node
+
+        if parent_pkgname in self._childless_node_names:
+            self._childless_node_names.remove(parent_pkgname)
+
+    def get_and_remove_outer_dep_pkgs(self) -> list[ForeignPackage]:
+        """
+        Returns all childless nodes of the dependency package graph and removes them.
+        """
+        new_childless_node_names = set()
+        result = []
+        for childless_node_name in self._childless_node_names:
+            childless_node = self.package_nodes[childless_node_name]
+
+            for parent in childless_node.parents.values():
+                new_deps = childless_node.pkg.get_all_recursive_foreign_dep_pkgs()
+                new_deps.add(childless_node.pkg.name)
+                parent.pkg.add_foreign_dependency_packages(new_deps)
+                del parent.children[childless_node_name]
+                if len(parent.children) == 0:
+                    new_childless_node_names.add(parent.pkg.name)
+
+            result.append(childless_node.pkg)
+        self._childless_node_names = new_childless_node_names
+        return result

plugins/decman-pacman/src/decman/plugins/pacman.py

@@ -0,0 +1,379 @@
+import re
+import shutil
+
+import pyalpm
+
+import decman.config as config
+import decman.core.command as command
+import decman.core.error as errors
+import decman.core.module as module
+import decman.core.output as output
+import decman.core.store as _store
+import decman.plugins as plugins
+
+
+def packages(fn):
+    """
+    Annotate that this function returns a set of pacman package names that should be installed.
+
+    Return type of ``fn``: ``set[str]``
+    """
+    fn.__pacman__packages__ = True
+    return fn
+
+
+def strip_dependency(dep: str) -> str:
+    """
+    Removes version spefications from a dependency name.
+    """
+    rx = re.compile("(=.*|>.*|<.*)")
+    return rx.sub("", dep)
+
+
+class Pacman(plugins.Plugin):
+    """
+    Plugin that manages pacman packages added directly to ``packages`` or declared by modules via
+    ``@packages``.
+    """
+
+    NAME = "pacman"
+
+    def __init__(self) -> None:
+        self.packages: set[str] = set()
+        self.ignored_packages: set[str] = set()
+        self.commands = PacmanCommands()
+        self.print_highlights = True
+        self.keywords = {
+            "pacsave",
+            "pacnew",
+            # These cause too many false positives IMO
+            # "warning",
+            # "error",
+            # "note",
+        }
+        self.database_signature_level = pyalpm.SIG_DATABASE_OPTIONAL
+        self.database_path = "/var/lib/pacman/"
+
+    def available(self) -> bool:
+        return shutil.which("pacman") is not None
+
+    def process_modules(self, store: _store.Store, modules: set[module.Module]):
+        # This is used to track changes in modules.
+        store.ensure("packages_for_module", {})
+
+        for mod in modules:
+            store["packages_for_module"].setdefault(mod.name, set())
+
+            packages = plugins.run_method_with_attribute(mod, "__pacman__packages__") or set()
+
+            if store["packages_for_module"][mod.name] != packages:
+                mod._changed = True
+                output.print_debug(
+                    f"Module '{mod.name}' set to changed due to modified pacman packages."
+                )
+
+            self.packages |= packages
+
+            store["packages_for_module"][mod.name] = packages
+
+    def apply(
+        self, store: _store.Store, dry_run: bool = False, params: list[str] | None = None
+    ) -> bool:
+        try:
+            pm = PacmanInterface(
+                self.commands,
+                self.print_highlights,
+                self.keywords,
+                self.database_signature_level,
+                self.database_path,
+            )
+
+            currently_installed_native = pm.get_native_explicit()
+            currently_installed_foreign = pm.get_foreign_explicit()
+            orphans = pm.get_native_orphans()
+            to_remove = (
+                (currently_installed_native | orphans) - self.packages - self.ignored_packages
+            )
+
+            actually_to_remove = set()
+            to_set_as_dependencies = set()
+
+            dependants_to_keep = self.packages | currently_installed_foreign
+            for package in to_remove:
+                dependants = pm.get_dependants(package)
+                if any(dependant in dependants_to_keep for dependant in dependants):
+                    to_set_as_dependencies.add(package)
+                else:
+                    actually_to_remove.add(package)
+
+            if actually_to_remove:
+                output.print_list("Removing pacman packages:", sorted(actually_to_remove))
+                if not dry_run:
+                    pm.remove(actually_to_remove)
+
+            if to_set_as_dependencies:
+                output.print_list(
+                    "Setting previously explicitly installed packages as dependencies:",
+                    sorted(to_set_as_dependencies),
+                )
+                if not dry_run:
+                    pm.set_as_dependencies(to_set_as_dependencies)
+
+            output.print_summary("Upgrading packages.")
+            if not dry_run:
+                pm.upgrade()
+
+            to_install = self.packages - currently_installed_native - self.ignored_packages
+            output.print_list("Installing pacman packages:", sorted(to_install))
+
+            if not dry_run:
+                pm.install(to_install)
+        except pyalpm.error as error:
+            output.print_error("Failed to query pacman databases with pyalpm.")
+            output.print_error(str(error))
+            output.print_traceback()
+            return False
+        except errors.CommandFailedError as error:
+            output.print_error(
+                "Pacman command exited with an unexpected return code. You may have cancelled a "
+                "pacman operation."
+            )
+            output.print_error(str(error))
+            if error.output:
+                output.print_command_output(error.output)
+            output.print_traceback()
+            return False
+        return True
+
+
+class PacmanCommands:
+    def list_pacman_repos(self) -> list[str]:
+        """
+        Running this command prints a newline seperated list of pacman repositories.
+        """
+        return ["pacman-conf", "--repo-list"]
+
+    def install(self, pkgs: set[str]) -> list[str]:
+        """
+        Running this command installs the given packages from pacman repositories.
+        """
+        return ["pacman", "-S", "--needed"] + list(pkgs)
+
+    def upgrade(self) -> list[str]:
+        """
+        Running this command upgrades all pacman packages from pacman repositories.
+        """
+        return ["pacman", "-Syu"]
+
+    def set_as_dependencies(self, pkgs: set[str]) -> list[str]:
+        """
+        Running this command sets the given packages as dependencies.
+        """
+        return ["pacman", "-D", "--asdeps"] + list(pkgs)
+
+    def set_as_explicit(self, pkgs: set[str]) -> list[str]:
+        """
+        Running this command sets the given as explicitly installed.
+        """
+        return ["pacman", "-D", "--asexplicit"] + list(pkgs)
+
+    def remove(self, pkgs: set[str]) -> list[str]:
+        """
+        Running this command removes the given packages and their dependencies
+        (that aren't required by other packages).
+        """
+        return ["pacman", "-Rs"] + list(pkgs)
+
+
+class PacmanInterface:
+    """
+    High level interface for running pacman commands.
+
+    On failure methods raise a ``CommandFailedError`` or ``pyalpm.error``.
+    """
+
+    def __init__(
+        self,
+        commands: PacmanCommands,
+        print_highlights: bool,
+        keywords: set[str],
+        dbsiglevel: int,
+        dbpath: str,
+    ) -> None:
+        self._commands = commands
+        self._print_highlights = print_highlights
+        self._keywords = keywords
+        self._dbsiglevel = dbsiglevel
+        self._dbpath = dbpath
+        self._handle = self._create_pyalpm_handle()
+        self._name_index = self._create_name_index()
+        self._provides_index = self._create_provides_index()
+
+    def _create_pyalpm_handle(self):
+        root = "/"
+
+        h = pyalpm.Handle(root, self._dbpath)
+
+        cmd = self._commands.list_pacman_repos()
+        repos = command.prg(cmd, pty=False).strip().split("\n")
+
+        # Empty string means no DBs
+        if "" in repos and len(repos) == 1:
+            return
+
+        for repo in repos:
+            h.register_syncdb(repo, self._dbsiglevel)
+
+        return h
+
+    def _create_name_index(self) -> set[str]:
+        return {pkg.name for db in self._handle.get_syncdbs() for pkg in db.pkgcache}
+
+    def _create_provides_index(self) -> dict[str, set[str]]:
+        out: dict[str, set[str]] = {}
+        for db in self._handle.get_syncdbs():
+            for pkg in db.pkgcache:
+                for p in pkg.provides:
+                    out.setdefault(strip_dependency(p), set()).add(pkg.name)
+        return out
+
+    def _is_native(self, package: str) -> bool:
+        return package in self._name_index
+
+    def get_native_explicit(self) -> set[str]:
+        """
+        Returns a set of explicitly installed native packages.
+        """
+        out: set[str] = set()
+        for pkg in self._handle.get_localdb().pkgcache:
+            if pkg.reason == pyalpm.PKG_REASON_EXPLICIT and self._is_native(pkg.name):
+                out.add(pkg.name)
+        return out
+
+        return packages
+
+    def get_native_orphans(self) -> set[str]:
+        """
+        Returns a set of orphaned native packages.
+        """
+        out: set[str] = set()
+        for pkg in self._handle.get_localdb().pkgcache:
+            if pkg.reason != pyalpm.PKG_REASON_DEPEND:
+                continue
+            if pkg.compute_requiredby():
+                continue
+            if self._is_native(pkg.name):
+                out.add(pkg.name)
+        return out
+
+    def get_foreign_explicit(self) -> set[str]:
+        """
+        Returns a set of explicitly installed foreign packages.
+        """
+        out: set[str] = set()
+        for pkg in self._handle.get_localdb().pkgcache:
+            if pkg.reason == pyalpm.PKG_REASON_EXPLICIT and not self._is_native(pkg.name):
+                out.add(pkg.name)
+        return out
+
+    def get_dependants(self, package: str) -> set[str]:
+        """
+        Returns a set of installed packages that depend on the given package.
+        Includes the package itself.
+        """
+        local = self._handle.get_localdb()
+
+        seen: set[str] = set()
+        stack = [package]
+
+        while stack:
+            name = stack.pop()
+            if name in seen:
+                continue
+            seen.add(name)
+
+            pkg = local.get_pkg(name)
+            if pkg is None:
+                continue
+
+            for dep in pkg.compute_requiredby():
+                if dep not in seen:
+                    stack.append(dep)
+
+        return seen
+
+    def set_as_dependencies(self, packages: set[str]):
+        """
+        Marks the given packages as dependency packages.
+        """
+        if not packages:
+            return
+
+        cmd = self._commands.set_as_dependencies(packages)
+        command.prg(cmd, pty=config.debug_output)
+
+    def install(self, packages: set[str]):
+        """
+        Installs the given packages. If the packages are already installed, marks them as
+        explicitly installed.
+        """
+        if not packages:
+            return
+
+        cmd = self._commands.install(packages)
+
+        pacman_output = command.prg(cmd)
+        self.print_highlighted_pacman_messages(pacman_output)
+
+        cmd = self._commands.set_as_explicit(packages)
+        command.prg(cmd, pty=config.debug_output)
+
+    def upgrade(self):
+        """
+        Upgrades all packages.
+        """
+        cmd = self._commands.upgrade()
+        pacman_output = command.prg(cmd)
+        self.print_highlighted_pacman_messages(pacman_output)
+
+    def remove(self, packages: set[str]):
+        """
+        Removes the given packages.
+        """
+        if not packages:
+            return
+
+        cmd = self._commands.remove(packages)
+        pacman_output = command.prg(cmd)
+        self.print_highlighted_pacman_messages(pacman_output)
+
+    def print_highlighted_pacman_messages(self, pacman_output: str):
+        """
+        Prints lines that contain pacman output keywords.
+        """
+        if not self._print_highlights:
+            return
+
+        lines = pacman_output.split("\n")
+        highlight_lines = []
+        for index, line in enumerate(lines):
+            for keyword in self._keywords:
+                if keyword.lower() in line.lower():
+                    highlight_lines.append(f"lines: {index}-{index + 2}")
+                    if index >= 1:
+                        highlight_lines.append(lines[index - 1])
+                    highlight_lines.append(line)
+                    if index + 1 < len(lines):
+                        highlight_lines.append(lines[index + 1])
+                    highlight_lines.append("")
+
+                    # Break, as to not print the same line again if it contains multiple keywords
+                    break
+
+        if highlight_lines:
+            output.print_summary("Pacman output highlights:")
+            for line in highlight_lines:
+                if line.startswith("lines:"):
+                    output.print_summary(line)
+                else:
+                    output.print_continuation(line)

plugins/decman-pacman/tests/test_decman_plugins_aur.py

@@ -0,0 +1,310 @@
+from typing import Any
+
+import pytest
+
+from decman.plugins import aur as aur_plugin
+
+
+class FakeStore(dict):
+    def ensure(self, key: str, default: Any) -> None:
+        if key not in self:
+            self[key] = default
+
+
+class FakeModule:
+    def __init__(self, name: str, aur_pkgs: set[str], custom_pkgs: set[Any]) -> None:
+        self.name = name
+        self._changed = False
+        self._aur_pkgs = aur_pkgs
+        self._custom_pkgs = custom_pkgs
+
+
+class FakeCustomPackage:
+    def __init__(self, pkgname: str) -> None:
+        self.pkgname = pkgname
+
+    def __hash__(self) -> int:  # needed because instances go into sets
+        return hash(self.pkgname)
+
+    def __eq__(self, other: object) -> bool:
+        return isinstance(other, FakeCustomPackage) and self.pkgname == other.pkgname
+
+    def parse(self, commands: Any) -> str:
+        # Whatever ForeignPackageManager expects; we just need something to feed into add_custom_pkg
+        return f"parsed-{self.pkgname}"
+
+
+def test_process_modules_collects_aur_and_custom_packages_and_marks_changed(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    aur = aur_plugin.AUR()
+    store = FakeStore()
+
+    cp1 = FakeCustomPackage("custom1")
+    cp2 = FakeCustomPackage("custom2")
+
+    mod1 = FakeModule("mod1", {"aur1", "aur2"}, {cp1})
+    mod2 = FakeModule("mod2", {"aur3"}, {cp2})
+
+    def fake_run_method_with_attribute(mod: FakeModule, attr: str):
+        if attr == "__aur__packages__":
+            return mod._aur_pkgs
+        if attr == "__custom__packages__":
+            return mod._custom_pkgs
+        return None
+
+    monkeypatch.setattr(
+        aur_plugin.plugins, "run_method_with_attribute", fake_run_method_with_attribute
+    )
+
+    aur.process_modules(store, {mod1, mod2})
+
+    # union of all aur/custom packages collected
+    assert aur.packages == {"aur1", "aur2", "aur3"}
+    assert aur.custom_packages == {cp1, cp2}
+
+    # stored per-module
+    assert store["aur_packages_for_module"]["mod1"] == {"aur1", "aur2"}
+    assert store["aur_packages_for_module"]["mod2"] == {"aur3"}
+    assert store["custom_packages_for_module"]["mod1"] == {str(cp1)}
+    assert store["custom_packages_for_module"]["mod2"] == {str(cp2)}
+
+    # first run: modules marked changed
+    assert mod1._changed is True
+    assert mod2._changed is True
+
+
+def test_apply_respects_ignored_packages_and_protects_their_dependencies(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    aur = aur_plugin.AUR()
+    store = FakeStore()
+
+    # Desired AUR/custom state
+    aur.packages = {"desired-aur"}
+    cp = FakeCustomPackage("custom-aur")
+    aur.custom_packages = {cp}
+
+    # Ignored foreign package (installed) and an ignored but *uninstalled* package
+    aur.ignored_packages = {"ignored-aur", "ignored-not-installed"}
+
+    # Fake PackageSearch
+    class FakePackageSearch:
+        def __init__(self, timeout: int) -> None:
+            self.timeout = timeout
+            self.added: list[Any] = []
+
+        def add_custom_pkg(self, parsed: Any) -> None:
+            self.added.append(parsed)
+
+    monkeypatch.setattr(aur_plugin, "PackageSearch", FakePackageSearch)
+    monkeypatch.setattr(aur_plugin.os, "makedirs", lambda *x, **kw: None)
+
+    # Fake pacman interface for foreign/native info
+    class FakePM:
+        def __init__(self, commands, print_highlights, keywords, dbsiglevel, dbpath) -> None:
+            self.commands = commands
+            self.print_highlights = print_highlights
+            self.keywords = keywords
+
+            self.remove_called_with: set[str] | None = None
+            self.set_as_deps_called_with: set[str] | None = None
+
+        def get_native_explicit(self) -> set[str]:
+            # no natives needed for this scenario
+            return set()
+
+        def get_foreign_explicit(self) -> set[str]:
+            # All explicitly installed foreign packages:
+            # - ignored-aur           (ignored, must stay and protect deps)
+            # - dep-of-ignored        (candidate; has ignored dependant)
+            # - orphan-foreign        (candidate; no dependants)
+            return {"ignored-aur", "dep-of-ignored", "orphan-foreign"}
+
+        def get_foreign_orphans(self) -> set[str]:
+            # orphan-foreign also considered orphan
+            return {"orphan-foreign"}
+
+        def get_dependants(self, pkg: str) -> set[str]:
+            if pkg == "dep-of-ignored":
+                # ignored-aur depends on dep-of-ignored -> must demote, not remove
+                return {"ignored-aur"}
+            if pkg == "orphan-foreign":
+                return set()
+            return set()
+
+        def remove(self, pkgs: set[str]) -> None:
+            self.remove_called_with = pkgs
+
+        def set_as_dependencies(self, pkgs: set[str]) -> None:
+            self.set_as_deps_called_with = pkgs
+
+    fake_pm = FakePM(None, None, None, None, None)
+
+    def fake_pm_ctor(
+        commands,
+        print_highlights,
+        keywords,
+        dbsiglevel,
+        dbpath,
+    ) -> FakePM:
+        fake_pm.commands = commands
+        fake_pm.print_highlights = print_highlights
+        fake_pm.keywords = keywords
+        return fake_pm
+
+    monkeypatch.setattr(aur_plugin, "AurPacmanInterface", fake_pm_ctor)
+
+    # Fake ForeignPackageManager
+    class FakeFPM:
+        def __init__(
+            self,
+            store_arg,
+            pm_arg,
+            package_search_arg,
+            commands_arg,
+            cache_dir,
+            build_dir,
+            makepkg_user,
+        ) -> None:
+            self.store = store_arg
+            self.pm = pm_arg
+            self.package_search = package_search_arg
+            self.commands = commands_arg
+            self.cache_dir = cache_dir
+            self.build_dir = build_dir
+            self.makepkg_user = makepkg_user
+
+            self.upgrade_args: tuple[bool, bool, set[str]] | None = None
+            self.install_called_with: list[str] | None = None
+
+        def upgrade(self, upgrade_devel: bool, force: bool, ignored: set[str]) -> None:
+            self.upgrade_args = (upgrade_devel, force, ignored)
+
+        def install(self, pkgs: list[str], force: bool = False) -> None:
+            # store as set to ignore ordering
+            self.install_called_with = pkgs
+
+    fake_fpm = FakeFPM(None, None, None, None, None, None, None)
+
+    def fake_fpm_ctor(
+        store_arg,
+        pm_arg,
+        package_search_arg,
+        commands_arg,
+        cache_dir,
+        build_dir,
+        makepkg_user,
+    ):
+        fake_fpm.store = store_arg
+        fake_fpm.pm = pm_arg
+        fake_fpm.package_search = package_search_arg
+        fake_fpm.commands = commands_arg
+        fake_fpm.cache_dir = cache_dir
+        fake_fpm.build_dir = build_dir
+        fake_fpm.makepkg_user = makepkg_user
+        return fake_fpm
+
+    monkeypatch.setattr(aur_plugin, "ForeignPackageManager", fake_fpm_ctor)
+
+    printed_lists: list[tuple[str, list[str]]] = []
+    printed_summaries: list[str] = []
+
+    def fake_print_list(title: str, items: list[str]) -> None:
+        printed_lists.append((title, items))
+
+    def fake_print_summary(msg: str) -> None:
+        printed_summaries.append(msg)
+
+    monkeypatch.setattr(aur_plugin.output, "print_list", fake_print_list)
+    monkeypatch.setattr(aur_plugin.output, "print_summary", fake_print_summary)
+
+    # Use params to test flag propagation into upgrade/install
+    ok = aur.apply(store, dry_run=False, params=["aur-upgrade-devel", "aur-force"])
+
+    assert ok is True
+
+    # Removal / demotion logic:
+    #
+    # custom_package_names = {"custom-aur"}
+    # currently_installed_foreign = {"ignored-aur", "dep-of-ignored", "orphan-foreign"}
+    # orphans = {"orphan-foreign"}
+    #
+    # to_remove candidates:
+    #   (foreign | orphans) - desired - custom - ignored
+    # = {"ignored-aur", "dep-of-ignored", "orphan-foreign"} ∪ {"orphan-foreign"}
+    #   - {"desired-aur"} - {"custom-aur"} - {"ignored-aur"}
+    # = {"dep-of-ignored", "orphan-foreign"}
+    #
+    # dependants_to_keep includes ignored installed foreign -> dep-of-ignored is demoted, orphan-foreign removed.
+
+    assert fake_pm.remove_called_with == {"orphan-foreign"}
+    assert fake_pm.set_as_deps_called_with == {"dep-of-ignored"}
+
+    # Ensure ignored packages were not removed
+    assert "ignored-aur" not in (fake_pm.remove_called_with or set())
+
+    # Upgrade called with flags and ignored set
+    assert fake_fpm.upgrade_args == (True, True, aur.ignored_packages)
+
+    # to_install = (packages | custom_names) - installed_foreign - ignored
+    #            = {"desired-aur", "custom-aur"} - {"ignored-aur", "dep-of-ignored", "orphan-foreign"}
+    #              - {"ignored-aur", "ignored-not-installed"}
+    #            = {"desired-aur", "custom-aur"}
+    assert set(fake_fpm.install_called_with or []) == {"desired-aur", "custom-aur"}
+    # ignored packages must not be installed
+    assert "ignored-aur" not in (fake_fpm.install_called_with or [])
+    assert "ignored-not-installed" not in (fake_fpm.install_called_with or [])
+
+    # Also check the printed lists mirror this
+    titles = [t for t, _ in printed_lists]
+    assert "Removing foreign packages:" in titles
+    assert "Setting previously explicitly installed foreign packages as dependencies:" in titles
+    assert "Installing foreign packages:" in titles
+
+    remove_list = next(items for t, items in printed_lists if "Removing foreign packages:" in t)
+    demote_list = next(
+        items
+        for t, items in printed_lists
+        if "Setting previously explicitly installed foreign packages as dependencies:" in t
+    )
+    install_list = next(items for t, items in printed_lists if "Installing foreign packages:" in t)
+
+    assert remove_list == ["orphan-foreign"]
+    assert demote_list == ["dep-of-ignored"]
+    # Order of install_list is deterministic because sorted() is used
+    assert install_list == ["custom-aur", "desired-aur"]
+    assert any("Upgrading foreign packages." in s for s in printed_summaries)
+
+
+def test_apply_returns_false_on_aur_rpc_error(monkeypatch: pytest.MonkeyPatch) -> None:
+    aur = aur_plugin.AUR()
+    store = FakeStore()
+
+    # Force PackageSearch to fail immediately
+    class FailingPackageSearch:
+        def __init__(self, timeout: int) -> None:
+            raise aur_plugin.AurRPCError("RPC down", "url")
+
+    monkeypatch.setattr(aur_plugin, "PackageSearch", FailingPackageSearch)
+    monkeypatch.setattr(aur_plugin.os, "makedirs", lambda *x, **kw: None)
+
+    errors_logged: list[str] = []
+    continuations: list[str] = []
+    traceback_called: list[bool] = []
+
+    def fake_print_error(msg: str) -> None:
+        errors_logged.append(msg)
+
+    def fake_print_traceback() -> None:
+        traceback_called.append(True)
+
+    monkeypatch.setattr(aur_plugin.output, "print_error", fake_print_error)
+    monkeypatch.setattr(aur_plugin.output, "print_traceback", fake_print_traceback)
+
+    ok = aur.apply(store, dry_run=False)
+
+    assert ok is False
+    assert any("AUR RPC" in msg or "fetch data from AUR RPC" in msg for msg in errors_logged)
+    assert any("RPC down" in msg for msg in errors_logged)
+    assert traceback_called

plugins/decman-pacman/tests/test_decman_plugins_aur_package.py

@@ -0,0 +1,743 @@
+import pathlib
+
+import pytest
+from decman.plugins.aur import package as pkg_mod
+from decman.plugins.aur.error import AurRPCError, PKGBUILDParseError
+from decman.plugins.aur.package import (
+    CustomPackage,
+    PackageInfo,
+    PackageSearch,
+)
+
+
+@pytest.fixture(autouse=True)
+def silence_output(monkeypatch):
+    # Avoid real I/O / prompts in tests by default
+    monkeypatch.setattr(pkg_mod.output, "print_debug", lambda *a, **k: None)
+    monkeypatch.setattr(pkg_mod.output, "print_summary", lambda *a, **k: None)
+    monkeypatch.setattr(
+        pkg_mod.output,
+        "prompt_number",
+        lambda *a, **k: 1,  # safe default
+    )
+
+
+# --- PackageInfo -----------------------------------------------------------
+
+
+def test_packageinfo_requires_exactly_one_source():
+    with pytest.raises(ValueError, match="cannot be None"):
+        PackageInfo(pkgname="a", pkgbase="a", version="1.0")
+
+    with pytest.raises(ValueError, match="cannot be set"):
+        PackageInfo(
+            pkgname="a",
+            pkgbase="a",
+            version="1.0",
+            git_url="git://example",
+            pkgbuild_directory="/tmp",
+        )
+
+
+class DummyPacman:
+    def __init__(self, installable: set[str]):
+        self._installable = installable
+        self.calls: list[str] = []
+
+    def is_installable(self, name: str) -> bool:
+        self.calls.append(name)
+        return name in self._installable
+
+
+def _make_pkg_for_deps() -> PackageInfo:
+    return PackageInfo(
+        pkgname="pkg",
+        pkgbase="pkg",
+        version="1.0",
+        git_url="git://example",
+        dependencies=("native>=1", "foreign=2"),
+        make_dependencies=("make-native", "make-foreign>=3"),
+        check_dependencies=("check-foreign<4", "check-native"),
+    )
+
+
+def test_packageinfo_foreign_and_native_dependencies_are_split_and_stripped():
+    pacman = DummyPacman(
+        {
+            "native>=1",
+            "make-native",
+            "check-native",
+        }
+    )
+    pkg = _make_pkg_for_deps()
+
+    assert pkg.native_dependencies(pacman) == ["native"]
+    assert pkg.foreign_dependencies(pacman) == ["foreign"]
+    assert pkg.native_make_dependencies(pacman) == ["make-native"]
+    assert pkg.foreign_make_dependencies(pacman) == ["make-foreign"]
+    assert pkg.native_check_dependencies(pacman) == ["check-native"]
+    assert pkg.foreign_check_dependencies(pacman) == ["check-foreign"]
+
+
+# --- CustomPackage ---------------------------------------------------------
+
+
+def test_custompackage_requires_exactly_one_source():
+    with pytest.raises(ValueError, match="cannot be None"):
+        CustomPackage("pkg", git_url=None, pkgbuild_directory=None)
+
+    with pytest.raises(ValueError, match="cannot be set"):
+        CustomPackage("pkg", git_url="git://example", pkgbuild_directory="/tmp")
+
+
+class DummyCommands:
+    """Minimal stub; only here so type checks pass where needed."""
+
+    pass
+
+
+@pytest.mark.parametrize(
+    "srcinfo, expected_version",
+    [
+        (
+            """
+            pkgbase = foo
+                pkgver = 1.2.3
+                pkgrel = 4
+            pkgname = foo
+            """,
+            "1.2.3-4",
+        ),
+        (
+            """
+            pkgbase = foo
+                pkgver = 1.2.3
+                pkgrel = 4
+                epoch = 2
+            pkgname = foo
+            """,
+            "2:1.2.3-4",
+        ),
+        (
+            """
+            pkgbase = foo
+                pkgver = 1.2.3
+            pkgname = foo
+            """,
+            "1.2.3",
+        ),
+    ],
+)
+def test_parse_srcinfo_version_handling(srcinfo: str, expected_version: str) -> None:
+    pkg = CustomPackage(pkgname="foo", git_url=None, pkgbuild_directory="/dummy")
+
+    info = pkg._parse_srcinfo(srcinfo)
+
+    assert info.pkgname == "foo"
+    assert info.pkgbase == "foo"
+    assert info.version == expected_version
+
+
+def test_parse_srcinfo_single_package_dependencies() -> None:
+    srcinfo = """
+    pkgbase = foo
+        pkgver = 1.2.3
+        pkgrel = 1
+        depends = bar>=1.0
+        makedepends = baz
+        checkdepends = qux
+
+    pkgname = foo
+    """
+
+    pkg = CustomPackage(pkgname="foo", git_url=None, pkgbuild_directory="/dummy")
+
+    info = pkg._parse_srcinfo(srcinfo)
+
+    assert info.dependencies == ("bar>=1.0",)
+    assert info.make_dependencies == ("baz",)
+    assert info.check_dependencies == ("qux",)
+
+
+def test_parse_srcinfo_split_package_uses_only_target_pkg_dependencies(monkeypatch) -> None:
+    # Ensure arch-specific keys match
+    monkeypatch.setattr(pkg_mod.config, "arch", "x86_64", raising=False)
+
+    srcinfo = """
+    pkgbase = clion
+        pkgver = 2025.3
+        pkgrel = 1
+        makedepends = rsync
+        depends = base-dep
+        depends_x86_64 = base-arch-dep
+
+    pkgname = clion
+        depends = libdbusmenu-glib
+        depends_x86_64 = clion-arch-dep
+        checkdepends = clion-check
+
+    pkgname = clion-jre
+        depends = jre-dep
+        makedepends = jre-make
+
+    pkgname = clion-cmake
+        depends = cmake-dep
+    """
+
+    pkg = CustomPackage(pkgname="clion", git_url=None, pkgbuild_directory="/dummy")
+
+    info = pkg._parse_srcinfo(srcinfo)
+
+    # version
+    assert info.pkgbase == "clion"
+    assert info.version == "2025.3-1"
+
+    # base deps + target pkg deps (including arch-specific)
+    assert info.dependencies == (
+        "base-dep",
+        "base-arch-dep",
+        "libdbusmenu-glib",
+        "clion-arch-dep",
+    )
+
+    # only base and target pkg makedepends
+    assert info.make_dependencies == ("rsync",)
+
+    # base + target pkg checkdepends
+    assert info.check_dependencies == ("clion-check",)
+
+
+def test_parse_srcinfo_arch_specific_ignored_for_other_arch(monkeypatch) -> None:
+    # Different arch → *_x86_64 keys should be ignored
+    monkeypatch.setattr(pkg_mod.config, "arch", "aarch64", raising=False)
+
+    srcinfo = """
+    pkgbase = foo
+        pkgver = 1.0
+        pkgrel = 1
+        depends_x86_64 = base-arch-dep
+
+    pkgname = foo
+        depends = common-dep
+        depends_x86_64 = pkg-arch-dep
+    """
+
+    pkg = CustomPackage(pkgname="foo", git_url=None, pkgbuild_directory="/dummy")
+
+    info = pkg._parse_srcinfo(srcinfo)
+
+    # Only common deps, no *_x86_64 because arch != x86_64
+    assert info.dependencies == ("common-dep",)
+
+
+def test_parse_srcinfo_missing_required_fields_raises() -> None:
+    # Missing pkgbase
+    srcinfo_no_pkgbase = """
+        pkgver = 1.0
+        pkgrel = 1
+        pkgname = foo
+    """
+    pkg = CustomPackage(pkgname="foo", git_url=None, pkgbuild_directory="/dummy")
+
+    with pytest.raises(PKGBUILDParseError) as excinfo:
+        pkg._parse_srcinfo(srcinfo_no_pkgbase)
+    assert "pkgbase/pkgver" in str(excinfo.value)
+
+    # Missing pkgver
+    srcinfo_no_pkgver = """
+        pkgbase = foo
+        pkgname = foo
+    """
+
+    with pytest.raises(PKGBUILDParseError) as excinfo2:
+        pkg._parse_srcinfo(srcinfo_no_pkgver)
+    assert "pkgbase/pkgver" in str(excinfo2.value)
+
+
+def test_parse_srcinfo_missing_target_pkg_raises() -> None:
+    srcinfo = """
+    pkgbase = foo
+        pkgver = 1.0
+        pkgrel = 1
+    pkgname = other
+    """
+
+    pkg = CustomPackage(pkgname="foo", git_url=None, pkgbuild_directory="/dummy")
+
+    with pytest.raises(PKGBUILDParseError) as excinfo:
+        pkg._parse_srcinfo(srcinfo)
+
+    msg = str(excinfo.value)
+    assert "Package foo not found in SRCINFO" in msg
+    assert "other" in msg  # listed in present packages
+
+
+def test_srcinfo_from_pkgbuild_directory_missing_dir_raises(tmp_path: pathlib.Path) -> None:
+    missing = tmp_path / "does-not-exist"
+
+    pkg = CustomPackage(pkgname="foo", git_url=None, pkgbuild_directory=str(missing))
+
+    with pytest.raises(PKGBUILDParseError) as excinfo:
+        pkg._srcinfo_from_pkgbuild_directory(DummyCommands())
+
+    msg = str(excinfo.value)
+    assert "does not exist or is not a directory" in msg
+
+
+def test_srcinfo_from_pkgbuild_directory_missing_pkgbuild_raises(tmp_path: pathlib.Path) -> None:
+    path = tmp_path / "pkgdir"
+    path.mkdir()
+
+    pkg = CustomPackage(pkgname="foo", git_url=None, pkgbuild_directory=str(path))
+
+    with pytest.raises(PKGBUILDParseError) as excinfo:
+        pkg._srcinfo_from_pkgbuild_directory(DummyCommands())
+
+    msg = str(excinfo.value)
+    assert "No PKGBUILD found" in msg
+
+
+def test_custom_package_equality_and_hash() -> None:
+    a1 = CustomPackage(
+        pkgname="foo", git_url="https://example.com/repo.git", pkgbuild_directory=None
+    )
+    a2 = CustomPackage(
+        pkgname="foo", git_url="https://example.com/repo.git", pkgbuild_directory=None
+    )
+    b = CustomPackage(pkgname="foo", git_url=None, pkgbuild_directory="/some/path")
+
+    assert a1 == a2
+    assert hash(a1) == hash(a2)
+
+    assert a1 != b
+    assert hash(a1) != hash(b)
+
+
+def test_custom_package_str_git_and_directory() -> None:
+    git_pkg = CustomPackage(
+        pkgname="foo",
+        git_url="https://example.com/repo.git",
+        pkgbuild_directory=None,
+    )
+    dir_pkg = CustomPackage(
+        pkgname="foo",
+        git_url=None,
+        pkgbuild_directory="/some/path",
+    )
+
+    assert "pkgname=foo" in str(git_pkg)
+    assert "git_url=https://example.com/repo.git" in str(git_pkg)
+
+    assert "pkgname=foo" in str(dir_pkg)
+    assert "pkgbuild_directory=/some/path" in str(dir_pkg)
+
+
+# --- PackageSearch: caching ------------------------------------------------
+
+
+def _make_pkg(name: str = "pkg") -> PackageInfo:
+    return PackageInfo(
+        pkgname=name,
+        pkgbase=name,
+        version="1.0",
+        git_url=f"git://example/{name}",
+        provides=("virt-" + name,),
+        dependencies=("dep",),
+        make_dependencies=(),
+        check_dependencies=(),
+    )
+
+
+def test_add_custom_pkg_caches_package():
+    search = PackageSearch()
+    pkg = _make_pkg("foo")
+
+    search.add_custom_pkg(pkg)
+
+    assert pkg in search._custom_packages
+    assert search._package_cache["foo"] is pkg
+    assert search._all_providers_cache["virt-foo"] == ["foo"]
+
+
+def test_try_caching_packages_skips_already_cached(monkeypatch):
+    search = PackageSearch()
+    pkg = _make_pkg("foo")
+    search._cache_pkg(pkg)
+
+    calls = []
+
+    def fake_get(*args, **kwargs):
+        calls.append((args, kwargs))
+        raise AssertionError("requests.get should not be called")
+
+    monkeypatch.setattr(pkg_mod.requests, "get", fake_get)
+
+    search.try_caching_packages(["foo"])
+    assert calls == []
+
+
+def test_try_caching_packages_caches_from_aur(monkeypatch):
+    search = PackageSearch()
+
+    def fake_get(url, timeout):
+        class Resp:
+            def json(self):
+                return {
+                    "type": "success",
+                    "results": [
+                        {
+                            "Name": "bar",
+                            "PackageBase": "bar-base",
+                            "Version": "2.0",
+                            "Depends": ["dep1"],
+                            "MakeDepends": ["make1"],
+                            "CheckDepends": ["check1"],
+                            "Provides": ["virt-bar"],
+                        }
+                    ],
+                }
+
+        return Resp()
+
+    monkeypatch.setattr(pkg_mod.requests, "get", fake_get)
+
+    search.try_caching_packages(["bar"])
+
+    assert "bar" in search._package_cache
+    info = search._package_cache["bar"]
+    assert isinstance(info, PackageInfo)
+    assert search._all_providers_cache["virt-bar"] == ["bar"]
+
+
+def test_try_caching_packages_aur_returns_error(monkeypatch):
+    search = PackageSearch()
+
+    def fake_get(url, timeout):
+        class Resp:
+            def json(self):
+                return {"type": "error", "error": "boom"}
+
+        return Resp()
+
+    monkeypatch.setattr(pkg_mod.requests, "get", fake_get)
+
+    with pytest.raises(AurRPCError):
+        search.try_caching_packages(["bar"])
+
+
+def test_try_caching_packages_request_exception_raises_aur_error(monkeypatch):
+    search = PackageSearch()
+
+    class DummyError(pkg_mod.requests.RequestException):
+        pass
+
+    def fake_get(url, timeout):
+        raise DummyError("boom")
+
+    monkeypatch.setattr(pkg_mod.requests, "get", fake_get)
+
+    with pytest.raises(AurRPCError):
+        search.try_caching_packages(["bar"])
+
+
+# --- PackageSearch: get_package_info --------------------------------------
+
+
+def test_get_package_info_returns_from_cache():
+    search = PackageSearch()
+    pkg = _make_pkg("foo")
+    search._cache_pkg(pkg)
+
+    result = search.get_package_info("foo")
+    assert result is pkg
+
+
+def test_get_package_info_returns_custom_package_if_not_cached():
+    search = PackageSearch()
+    pkg = _make_pkg("foo")
+    search._custom_packages.append(pkg)
+
+    result = search.get_package_info("foo")
+
+    assert result is pkg
+    assert search._package_cache["foo"] is pkg
+
+
+def test_get_package_info_aur_not_found_returns_none(monkeypatch):
+    search = PackageSearch()
+
+    def fake_get(url, timeout):
+        class Resp:
+            def json(self):
+                return {"type": "success", "resultcount": 0, "results": []}
+
+        return Resp()
+
+    monkeypatch.setattr(pkg_mod.requests, "get", fake_get)
+
+    result = search.get_package_info("foo")
+    assert result is None
+    assert "foo" not in search._package_cache
+
+
+def test_get_package_info_aur_success_caches_and_returns(monkeypatch):
+    search = PackageSearch()
+
+    def fake_get(url, timeout):
+        class Resp:
+            def json(self):
+                return {
+                    "type": "success",
+                    "resultcount": 1,
+                    "results": [
+                        {
+                            "Name": "foo",
+                            "PackageBase": "foo-base",
+                            "Version": "1.2",
+                            "Depends": ["dep1"],
+                            "MakeDepends": ["make1"],
+                            "CheckDepends": ["check1"],
+                            "Provides": ["virt-foo"],
+                        }
+                    ],
+                }
+
+        return Resp()
+
+    monkeypatch.setattr(pkg_mod.requests, "get", fake_get)
+
+    result = search.get_package_info("foo")
+    assert isinstance(result, PackageInfo)
+    assert result.pkgname == "foo"
+    assert search._package_cache["foo"] is result
+
+
+def test_get_package_info_aur_returns_error(monkeypatch):
+    search = PackageSearch()
+
+    def fake_get(url, timeout):
+        class Resp:
+            def json(self):
+                return {"type": "error", "error": "boom"}
+
+        return Resp()
+
+    monkeypatch.setattr(pkg_mod.requests, "get", fake_get)
+
+    with pytest.raises(AurRPCError):
+        search.get_package_info("foo")
+
+
+def test_get_package_info_request_exception_raises_aur_error(monkeypatch):
+    search = PackageSearch()
+
+    class DummyError(pkg_mod.requests.RequestException):
+        pass
+
+    def fake_get(url, timeout):
+        raise DummyError("boom")
+
+    monkeypatch.setattr(pkg_mod.requests, "get", fake_get)
+
+    with pytest.raises(AurRPCError):
+        search.get_package_info("foo")
+
+
+# --- PackageSearch: find_provider -----------------------------------------
+
+
+def test_find_provider_uses_selected_providers_cache():
+    search = PackageSearch()
+    pkg = _make_pkg("foo")
+    search._selected_providers_cache["dep"] = pkg
+
+    result = search.find_provider("dep")
+    assert result is pkg
+
+
+def test_find_provider_exact_name_match(monkeypatch):
+    search = PackageSearch()
+    pkg = _make_pkg("dep")
+
+    def fake_get_package_info(name: str):
+        assert name == "dep"
+        return pkg
+
+    monkeypatch.setattr(search, "get_package_info", fake_get_package_info)
+
+    result = search.find_provider("dep")
+    assert result is pkg
+    assert search._selected_providers_cache["dep"] is pkg
+
+
+def test_find_provider_single_known_provider(monkeypatch):
+    search = PackageSearch()
+    pkg = _make_pkg("provider")
+    search._all_providers_cache["dep"] = ["provider"]
+
+    def fake_get_package_info(name: str):
+        if name == "dep":
+            return None
+        assert name == "provider"
+        return pkg
+
+    monkeypatch.setattr(search, "get_package_info", fake_get_package_info)
+
+    result = search.find_provider("dep")
+    assert result is pkg
+    assert search._selected_providers_cache["dep"] is pkg
+
+
+def test_find_provider_aur_search_not_found(monkeypatch):
+    search = PackageSearch()
+
+    def fake_get_package_info(name: str):
+        # Exact name match should fail
+        return None
+
+    monkeypatch.setattr(search, "get_package_info", fake_get_package_info)
+
+    def fake_get(url, timeout):
+        class Resp:
+            def json(self):
+                return {"type": "success", "resultcount": 0, "results": []}
+
+        return Resp()
+
+    monkeypatch.setattr(pkg_mod.requests, "get", fake_get)
+
+    result = search.find_provider("dep")
+    assert result is None
+
+
+def test_find_provider_aur_search_single_result(monkeypatch):
+    search = PackageSearch()
+    pkg = _make_pkg("provider")
+
+    def fake_get_package_info(name: str):
+        # first call for stripped_dependency -> None
+        if name == "dep":
+            return None
+        assert name == "provider"
+        return pkg
+
+    monkeypatch.setattr(search, "get_package_info", fake_get_package_info)
+
+    def fake_get(url, timeout):
+        class Resp:
+            def json(self):
+                return {
+                    "type": "success",
+                    "resultcount": 1,
+                    "results": [{"Name": "provider"}],
+                }
+
+        return Resp()
+
+    monkeypatch.setattr(pkg_mod.requests, "get", fake_get)
+
+    result = search.find_provider("dep")
+    assert result is pkg
+
+
+def test_find_provider_aur_search_multiple_results_calls_choose_provider(monkeypatch):
+    search = PackageSearch()
+
+    def fake_get_package_info(name: str):
+        # no exact match
+        return None
+
+    monkeypatch.setattr(search, "get_package_info", fake_get_package_info)
+
+    def fake_get(url, timeout):
+        class Resp:
+            def json(self):
+                return {
+                    "type": "success",
+                    "resultcount": 2,
+                    "results": [{"Name": "a"}, {"Name": "b"}],
+                }
+
+        return Resp()
+
+    monkeypatch.setattr(pkg_mod.requests, "get", fake_get)
+
+    sentinel = object()
+
+    def fake_choose(dep, providers, where):
+        assert dep == "dep"
+        assert providers == ["a", "b"]
+        assert where == "AUR"
+        return sentinel
+
+    monkeypatch.setattr(search, "_choose_provider", fake_choose)
+
+    result = search.find_provider("dep")
+    assert result is sentinel
+
+
+def test_find_provider_aur_search_error(monkeypatch):
+    search = PackageSearch()
+
+    def fake_get_package_info(name: str):
+        return None
+
+    monkeypatch.setattr(search, "get_package_info", fake_get_package_info)
+
+    def fake_get(url, timeout):
+        class Resp:
+            def json(self):
+                return {"type": "error", "error": "boom"}
+
+        return Resp()
+
+    monkeypatch.setattr(pkg_mod.requests, "get", fake_get)
+
+    with pytest.raises(AurRPCError):
+        search.find_provider("dep")
+
+
+def test_find_provider_aur_search_request_exception_raises_aur_error(monkeypatch):
+    search = PackageSearch()
+
+    def fake_get_package_info(name: str):
+        return None
+
+    monkeypatch.setattr(search, "get_package_info", fake_get_package_info)
+
+    class DummyError(pkg_mod.requests.RequestException):
+        pass
+
+    def fake_get(url, timeout):
+        raise DummyError("boom")
+
+    monkeypatch.setattr(pkg_mod.requests, "get", fake_get)
+
+    with pytest.raises(AurRPCError):
+        search.find_provider("dep")
+
+
+# --- PackageSearch: _choose_provider --------------------------------------
+
+
+def test_choose_provider_prompts_and_caches(monkeypatch):
+    search = PackageSearch()
+    providers = ["a", "b", "c"]
+    selected_pkg = _make_pkg("b")
+
+    # override prompt to select "2" (provider "b")
+    monkeypatch.setattr(
+        pkg_mod.output,
+        "prompt_number",
+        lambda *a, **k: 2,
+    )
+
+    def fake_get_package_info(name: str):
+        assert name == "b"
+        return selected_pkg
+
+    monkeypatch.setattr(search, "get_package_info", fake_get_package_info)
+
+    result = search._choose_provider("dep", providers, "AUR")
+    assert result is selected_pkg
+    assert search._selected_providers_cache["dep"] is selected_pkg

plugins/decman-pacman/tests/test_decman_plugins_aur_resolver.py

@@ -0,0 +1,87 @@
+import pytest
+from decman.plugins.aur.error import DependencyCycleError
+from decman.plugins.aur.resolver import DepGraph, ForeignPackage
+
+
+def test_add_dependency():
+    graph = DepGraph()
+
+    graph.add_requirement("A", None)
+    graph.add_requirement("B1", "A")
+    graph.add_requirement("B2", "A")
+    graph.add_requirement("C", "B1")
+
+    assert "B1" in graph.package_nodes["A"].children
+    assert "B2" in graph.package_nodes["A"].children
+    assert "C" in graph.package_nodes["B1"].children
+
+
+def test_cyclic_dependency_raises():
+    graph = DepGraph()
+
+    graph.add_requirement("A", None)
+    graph.add_requirement("B", "A")
+    graph.add_requirement("C", "B")
+
+    with pytest.raises(DependencyCycleError):
+        graph.add_requirement("A", "C")
+
+
+def _build_graph_for_outer_deps() -> DepGraph:
+    graph = DepGraph()
+
+    # Roots
+    graph.add_requirement("A", None)
+    graph.add_requirement("V", None)
+
+    # Level B
+    graph.add_requirement("B1", "A")
+    graph.add_requirement("B2", "A")
+    graph.add_requirement("B3", "A")
+
+    # Extra dependency B1 -> B2
+    graph.add_requirement("B1", "B2")
+
+    # Level C
+    graph.add_requirement("C1", "B1")
+    graph.add_requirement("C2", "B1")
+
+    # Level D + cycle-ish edges
+    graph.add_requirement("D", "C1")
+    graph.add_requirement("C2", "D")
+
+    # Foreign packages and their foreign deps
+    defs = {
+        "V": [],
+        "A": ["B1", "B2", "B3", "C1", "C2", "D"],
+        "B1": ["C1", "C2", "D"],
+        "B2": ["B1", "C1", "C2", "D"],
+        "B3": [],
+        "C1": ["D", "C2"],
+        "C2": [],
+        "D": ["C2"],
+    }
+
+    for name, deps in defs.items():
+        pkg = ForeignPackage(name)
+        pkg.add_foreign_dependency_packages(deps)
+
+    return graph
+
+
+def _assert_outer_dep_names(graph: DepGraph, expected: set[str]) -> None:
+    result = graph.get_and_remove_outer_dep_pkgs()
+    names = {pkg.name for pkg in result}
+    assert names == expected
+
+
+def test_get_and_remove_outer_deps_sequence():
+    graph = _build_graph_for_outer_deps()
+
+    _assert_outer_dep_names(graph, {"C2", "B3", "V"})
+    _assert_outer_dep_names(graph, {"D"})
+    _assert_outer_dep_names(graph, {"C1"})
+    _assert_outer_dep_names(graph, {"B1"})
+    _assert_outer_dep_names(graph, {"B2"})
+    _assert_outer_dep_names(graph, {"A"})
+    _assert_outer_dep_names(graph, set())

plugins/decman-pacman/tests/test_decman_plugins_pacman.py

@@ -0,0 +1,313 @@
+from typing import Any
+
+import pytest
+
+from decman.plugins import pacman as pacman_plugin
+
+
+@pytest.mark.parametrize(
+    "dep,expected",
+    [
+        ("foo", "foo"),
+        ("foo=1.0", "foo"),
+        ("bar>=2", "bar"),
+        ("baz<3", "baz"),
+        ("multi=1.0-2", "multi"),
+    ],
+)
+def test_strip_dependency(dep, expected):
+    assert pacman_plugin.strip_dependency(dep) == expected
+
+
+class FakeStore(dict):
+    def ensure(self, key: str, default: Any) -> None:
+        if key not in self:
+            self[key] = default
+
+
+class FakeModule:
+    def __init__(self, name: str, packages: set[str]) -> None:
+        self.name = name
+        self._changed = False
+        self._packages = packages
+
+
+def test_process_modules_collects_packages_and_marks_changed(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    pacman = pacman_plugin.Pacman()
+    store = FakeStore()
+    mod1 = FakeModule("mod1", {"pkg1", "pkg2"})
+    mod2 = FakeModule("mod2", {"pkg3"})
+
+    def fake_run_method_with_attribute(mod: FakeModule, attr: str) -> set[str]:
+        assert attr == "__pacman__packages__"
+        return mod._packages
+
+    monkeypatch.setattr(
+        pacman_plugin.plugins,
+        "run_method_with_attribute",
+        fake_run_method_with_attribute,
+    )
+
+    pacman.process_modules(store, {mod1, mod2})
+
+    # packages collected
+    assert pacman.packages == {"pkg1", "pkg2", "pkg3"}
+    # stored mapping per module
+    assert store["packages_for_module"]["mod1"] == {"pkg1", "pkg2"}
+    assert store["packages_for_module"]["mod2"] == {"pkg3"}
+    # modules marked changed (first run)
+    assert mod1._changed is True
+    assert mod2._changed is True
+
+
+def test_apply_dry_run_computes_sets_and_does_not_call_pacman(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    pacman = pacman_plugin.Pacman()
+    store = FakeStore()
+
+    # Desired state
+    pacman.packages = {"keep-explicit", "new-pkg"}
+
+    # Fake PacmanInterface returned by plugin module
+    class FakePM:
+        def __init__(
+            self, commands, print_highlights, keywords, database_signature_level, database_path
+        ) -> None:  # noqa: D401
+            self.commands = commands
+            self.print_highlights = print_highlights
+            self.keywords = keywords
+            self.remove_called_with: set[str] | None = None
+            self.set_as_deps_called_with: set[str] | None = None
+            self.upgrade_called = False
+            self.install_called_with: set[str] | None = None
+
+        def get_native_explicit(self) -> set[str]:
+            # keep-explicit (in desired), old-explicit (to demote/remove)
+            return {"keep-explicit", "old-explicit"}
+
+        def get_foreign_explicit(self) -> set[str]:
+            # foreign-package protects its deps
+            return {"foreign-pkg"}
+
+        def get_native_orphans(self) -> set[str]:
+            # orphan-explicit is also candidate
+            return {"orphan-explicit"}
+
+        def get_dependants(self, pkg: str) -> set[str]:
+            # old-explicit has a foreign dependant -> demote to dep
+            # orphan-explicit has no dependants -> remove
+            if pkg == "old-explicit":
+                return {"foreign-pkg"}
+            if pkg == "orphan-explicit":
+                return set()
+            return set()
+
+        def remove(self, pkgs: set[str]) -> None:
+            self.remove_called_with = pkgs
+
+        def set_as_dependencies(self, pkgs: set[str]) -> None:
+            self.set_as_deps_called_with = pkgs
+
+        def upgrade(self) -> None:
+            self.upgrade_called = True
+
+        def install(self, pkgs: set[str]) -> None:
+            self.install_called_with = pkgs
+
+    fake_pm = FakePM(None, None, None, None, None)
+
+    def fake_pm_ctor(
+        commands, print_highlights, keywords, database_signature_level, database_path
+    ) -> FakePM:
+        # constructor used in Pacman.apply
+        fake_pm.commands = commands
+        fake_pm.print_highlights = print_highlights
+        fake_pm.keywords = keywords
+        return fake_pm
+
+    monkeypatch.setattr(pacman_plugin, "PacmanInterface", fake_pm_ctor)
+
+    printed_lists: list[tuple[str, list[str]]] = []
+    printed_summaries: list[str] = []
+
+    def fake_print_list(title: str, items: list[str]) -> None:
+        printed_lists.append((title, items))
+
+    def fake_print_summary(msg: str) -> None:
+        printed_summaries.append(msg)
+
+    monkeypatch.setattr(pacman_plugin.output, "print_list", fake_print_list)
+    monkeypatch.setattr(pacman_plugin.output, "print_summary", fake_print_summary)
+
+    ok = pacman.apply(store, dry_run=True)
+
+    assert ok is True
+
+    # to_remove = (native | orphans) - desired
+    #           = {keep-explicit, old-explicit} ∪ {orphan-explicit} - {keep-explicit, new-pkg}
+    #           = {old-explicit, orphan-explicit}
+    #
+    # old-explicit has foreign dependant -> demoted to dep
+    # orphan-explicit has no dependants -> removed
+
+    # printed lists (titles and contents)
+    titles = [t for t, _ in printed_lists]
+    assert "Removing pacman packages:" in titles
+    assert "Setting previously explicitly installed packages as dependencies:" in titles
+    assert "Installing pacman packages:" in titles
+
+    # find lists by title
+    remove_list = next(items for t, items in printed_lists if "Removing pacman packages:" in t)
+    demote_list = next(
+        items
+        for t, items in printed_lists
+        if "Setting previously explicitly installed packages as dependencies:" in t
+    )
+    install_list = next(items for t, items in printed_lists if "Installing pacman packages:" in t)
+
+    assert remove_list == ["orphan-explicit"]
+    assert demote_list == ["old-explicit"]
+    # to_install = desired - currently_installed_native
+    #            = {keep-explicit, new-pkg} - {keep-explicit, old-explicit}
+    #            = {new-pkg}
+    assert install_list == ["new-pkg"]
+
+    # Upgrade summary printed even in dry-run
+    assert any("Upgrading packages." in s for s in printed_summaries)
+
+    # No mutating calls in dry-run
+    assert fake_pm.remove_called_with is None
+    assert fake_pm.set_as_deps_called_with is None
+    assert fake_pm.upgrade_called is False
+    assert fake_pm.install_called_with is None
+
+
+def test_apply_returns_false_on_command_failure(monkeypatch: pytest.MonkeyPatch) -> None:
+    pacman = pacman_plugin.Pacman()
+    store = FakeStore()
+    pacman.packages = set()
+
+    class FailingPM:
+        def __init__(self, *args, **kwargs) -> None:  # noqa: D401
+            pass
+
+        def get_native_explicit(self) -> set[str]:
+            raise pacman_plugin.errors.CommandFailedError(["get_native_explicit"], "boom")
+
+    monkeypatch.setattr(pacman_plugin, "PacmanInterface", FailingPM)
+
+    errors_logged: list[str] = []
+    continuations: list[str] = []
+    traceback_called = []
+
+    def fake_print_error(msg: str) -> None:
+        errors_logged.append(msg)
+
+    def fake_print_traceback() -> None:
+        traceback_called.append(True)
+
+    def fake_print_continuation(msg: str) -> None:
+        continuations.append(msg)
+
+    monkeypatch.setattr(pacman_plugin.output, "print_error", fake_print_error)
+    monkeypatch.setattr(pacman_plugin.output, "print_traceback", fake_print_traceback)
+    monkeypatch.setattr(pacman_plugin.output, "print_continuation", fake_print_continuation)
+
+    ok = pacman.apply(store, dry_run=False)
+
+    assert ok is False
+    assert any("Pacman command exited with an unexpected" in msg for msg in errors_logged)
+    assert any("boom" in msg for msg in continuations)
+    assert traceback_called  # at least once
+
+
+def test_ignored_packages_are_not_removed_or_installed(monkeypatch: pytest.MonkeyPatch) -> None:
+    pacman = pacman_plugin.Pacman()
+    store = FakeStore()
+
+    # Desired state: "already" and "new" should be managed normally.
+    # "ignored-installed" is currently installed but not desired -> would normally be removed.
+    # "ignored-uninstalled" is desired but not installed -> would normally be installed.
+    pacman.packages = {"already", "new", "ignored-uninstalled"}
+    pacman.ignored_packages = {"ignored-installed", "ignored-uninstalled"}
+
+    class FakePM:
+        def __init__(
+            self, commands, print_highlights, keywords, database_signature_level, database_path
+        ) -> None:  # noqa: D401
+            self.commands = commands
+            self.print_highlights = print_highlights
+            self.keywords = keywords
+
+            self.remove_called_with: set[str] | None = None
+            self.install_called_with: set[str] | None = None
+            self.set_as_deps_called_with: set[str] | None = None
+            self.upgrade_called = False
+
+        def get_native_explicit(self) -> set[str]:
+            # currently installed explicit packages
+            return {"ignored-installed", "already"}
+
+        def get_foreign_explicit(self) -> set[str]:
+            return set()
+
+        def get_native_orphans(self) -> set[str]:
+            return set()
+
+        def get_dependants(self, pkg: str) -> set[str]:
+            return set()
+
+        def remove(self, pkgs: set[str]) -> None:
+            self.remove_called_with = pkgs
+
+        def set_as_dependencies(self, pkgs: set[str]) -> None:
+            self.set_as_deps_called_with = pkgs
+
+        def upgrade(self) -> None:
+            self.upgrade_called = True
+
+        def install(self, pkgs: set[str]) -> None:
+            self.install_called_with = pkgs
+
+    fake_pm = FakePM(None, None, None, None, None)
+
+    def fake_pm_ctor(
+        commands, print_highlights, keywords, database_signature_level, database_path
+    ) -> FakePM:
+        fake_pm.commands = commands
+        fake_pm.print_highlights = print_highlights
+        fake_pm.keywords = keywords
+        return fake_pm
+
+    monkeypatch.setattr(pacman_plugin, "PacmanInterface", fake_pm_ctor)
+
+    printed_lists: list[tuple[str, list[str]]] = []
+
+    def fake_print_list(title: str, items: list[str]) -> None:
+        printed_lists.append((title, items))
+
+    # don't care about summaries here
+    monkeypatch.setattr(pacman_plugin.output, "print_list", fake_print_list)
+    monkeypatch.setattr(pacman_plugin.output, "print_summary", lambda *_args, **_kw: None)
+
+    ok = pacman.apply(store, dry_run=False)
+
+    assert ok is True
+
+    # Ignored packages must never be passed to remove() or install()
+    assert (
+        fake_pm.remove_called_with is None or "ignored-installed" not in fake_pm.remove_called_with
+    )
+    assert fake_pm.install_called_with is not None
+    assert "ignored-uninstalled" not in fake_pm.install_called_with
+
+    # Also ensure the printed install list doesn't contain ignored packages
+    install_items = next(
+        items for title, items in printed_lists if "Installing pacman packages:" in title
+    )
+    assert "ignored-uninstalled" not in install_items
+    # "new" is the only package that should be installed in this scenario
+    assert install_items == ["new"]

plugins/decman-systemd/pyproject.toml

@@ -0,0 +1,20 @@
+[project]
+name = "decman-systemd"
+version = "1.0.0"
+requires-python = ">=3.13"
+dependencies = ["decman==1.0.0"]
+
+[project.entry-points."decman.plugins"]
+systemd = "decman.plugins.systemd:Systemd"
+
+[build-system]
+requires = ["setuptools>=61.0"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.packages.find]
+where = ["src"]
+namespaces = true
+include = ["decman.plugins*"]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]

plugins/decman-systemd/src/decman/plugins/systemd.py

@@ -0,0 +1,253 @@
+import shutil
+
+import decman.config as config
+import decman.core.command as command
+import decman.core.error as errors
+import decman.core.module as module
+import decman.core.output as output
+import decman.core.store as _store
+import decman.plugins as plugins
+
+
+def units(fn):
+    """
+    Annotate that this function returns a set of systemd unit names that should be enabled.
+
+    Return type of ``fn``: ``set[str]``
+    """
+    fn.__systemd__units__ = True
+    return fn
+
+
+def user_units(fn):
+    """
+    Annotate that this function returns a dict of users and systemd user unit names that should be
+    enabled.
+
+    Return type of ``fn``: ``dict[str, set[str]]``
+    """
+    fn.__systemd__user__units__ = True
+    return fn
+
+
+class SystemdCommands:
+    """
+    Default commands for the Systemd plugin.
+    """
+
+    def enable_units(self, units: set[str]) -> list[str]:
+        """
+        Running this command enables the given systemd units.
+        """
+        return ["systemctl", "enable"] + list(units)
+
+    def disable_units(self, units: set[str]) -> list[str]:
+        """
+        Running this command disables the given systemd units.
+        """
+        return ["systemctl", "disable"] + list(units)
+
+    def enable_user_units(self, units: set[str], user: str) -> list[str]:
+        """
+        Running this command enables the given systemd units for the user.
+        """
+        return ["systemctl", "--user", "-M", f"{user}@", "enable"] + list(units)
+
+    def disable_user_units(self, units: set[str], user: str) -> list[str]:
+        """
+        Running this command disables the given systemd units for the user.
+        """
+        return ["systemctl", "--user", "-M", f"{user}@", "disable"] + list(units)
+
+    def daemon_reload(self) -> list[str]:
+        """
+        Running this command reloads the systemd daemon.
+        """
+        return ["systemctl", "daemon-reload"]
+
+    def user_daemon_reload(self, user: str) -> list[str]:
+        """
+        Running this command reloads the systemd daemon for the given user.
+        """
+        return ["systemctl", "--user", "-M", f"{user}@", "daemon-reload"]
+
+
+class Systemd(plugins.Plugin):
+    NAME = "systemd"
+
+    def __init__(self) -> None:
+        self.enabled_units: set[str] = set()
+        self.enabled_user_units: dict[str, set[str]] = {}
+        self.commands = SystemdCommands()
+
+    def available(self) -> bool:
+        return shutil.which("systemctl") is not None
+
+    def process_modules(self, store: _store.Store, modules: set[module.Module]):
+        # These store keys are used to track changes in modules.
+        # This way when these change, module can be marked as changed
+        store.ensure("systemd_units_for_module", {})
+        store.ensure("systemd_user_units_for_module", {})
+
+        for mod in modules:
+            store["systemd_units_for_module"].setdefault(mod.name, set())
+            store["systemd_user_units_for_module"].setdefault(mod.name, {})
+
+            units = plugins.run_method_with_attribute(mod, "__systemd__units__") or set()
+            user_units = plugins.run_method_with_attribute(mod, "__systemd__user__units__") or {}
+
+            if store["systemd_units_for_module"][mod.name] != units:
+                mod._changed = True
+                output.print_debug(
+                    f"Module '{mod.name}' set to changed due to modified systemd units."
+                )
+
+            if store["systemd_user_units_for_module"][mod.name] != user_units:
+                mod._changed = True
+                output.print_debug(
+                    f"Module '{mod.name}' set to changed due to modified systemd user units."
+                )
+
+            self.enabled_units |= units
+            for user, u_units in user_units.items():
+                self.enabled_user_units.setdefault(user, set()).update(u_units)
+
+            store["systemd_units_for_module"][mod.name] = units
+            store["systemd_user_units_for_module"][mod.name] = user_units
+
+    def apply(
+        self, store: _store.Store, dry_run: bool = False, params: list[str] | None = None
+    ) -> bool:
+        store.ensure("systemd_units", set())
+        store.ensure("systemd_user_units", {})
+
+        units_to_enable = set()
+        units_to_disable = set()
+        user_units_to_enable: dict[str, set[str]] = {}
+        user_units_to_disable: dict[str, set[str]] = {}
+
+        for unit in self.enabled_units:
+            if unit not in store["systemd_units"]:
+                units_to_enable.add(unit)
+
+        for unit in store["systemd_units"]:
+            if unit not in self.enabled_units:
+                units_to_disable.add(unit)
+
+        for user, units in self.enabled_user_units.items():
+            store["systemd_user_units"].setdefault(user, set())
+            user_units_to_enable.setdefault(user, set())
+
+            for unit in units:
+                if unit not in store["systemd_user_units"][user]:
+                    user_units_to_enable[user].add(unit)
+
+        for user, units in store["systemd_user_units"].items():
+            self.enabled_user_units.setdefault(user, set())
+            user_units_to_disable.setdefault(user, set())
+
+            for unit in units:
+                if unit not in self.enabled_user_units[user]:
+                    user_units_to_disable[user].add(unit)
+
+        try:
+            output.print_info("Reloading systemd daemon.")
+            if not dry_run:
+                self.reload_daemon()
+
+            output.print_info("Reloading systemd daemon for users.")
+            if not dry_run:
+                for user in user_units_to_enable.keys() | user_units_to_disable.keys():
+                    self.reload_user_daemon(user)
+
+            output.print_list("Enabling systemd units:", list(units_to_enable))
+            if not dry_run:
+                self.enable_units(store, units_to_enable)
+
+            output.print_list("Disabling systemd units:", list(units_to_disable))
+            if not dry_run:
+                self.disable_units(store, units_to_disable)
+
+            for user, units in user_units_to_enable.items():
+                output.print_list(f"Enabling systemd units for {user}:", list(units))
+                if not dry_run:
+                    self.enable_user_units(store, units, user)
+
+            for user, units in user_units_to_disable.items():
+                output.print_list(f"Disabling systemd units for {user}:", list(units))
+                if not dry_run:
+                    self.disable_user_units(store, units, user)
+        except errors.CommandFailedError as error:
+            output.print_error("Running a systemd command failed.")
+            output.print_error(str(error))
+            if error.output:
+                output.print_command_output(error.output)
+            output.print_traceback()
+            return False
+        return True
+
+    def enable_units(self, store: _store.Store, units: set[str]):
+        """
+        Enables the given units.
+        """
+        if not units:
+            return
+
+        cmd = self.commands.enable_units(units)
+        command.prg(cmd, pty=config.debug_output)
+
+        store["systemd_units"] |= units
+
+    def disable_units(self, store: _store.Store, units: set[str]):
+        """
+        Disables the given units.
+        """
+        if not units:
+            return
+
+        cmd = self.commands.disable_units(units)
+        command.prg(cmd, pty=config.debug_output)
+
+        store["systemd_units"] -= units
+
+    def enable_user_units(self, store: _store.Store, units: set[str], user: str):
+        """
+        Enables the given units for the given user.
+        """
+        if not units:
+            return
+
+        cmd = self.commands.enable_user_units(units, user)
+        command.prg(cmd, pty=config.debug_output)
+
+        store["systemd_user_units"].setdefault(user, set())
+        store["systemd_user_units"][user] |= units
+
+    def disable_user_units(self, store: _store.Store, units: set[str], user: str):
+        """
+        Disables the given units for the given user.
+        """
+        if not units:
+            return
+
+        cmd = self.commands.disable_user_units(units, user)
+        command.prg(cmd, pty=config.debug_output)
+
+        store["systemd_user_units"].setdefault(user, set())
+        store["systemd_user_units"][user] -= units
+
+    def reload_user_daemon(self, user: str):
+        """
+        Reloads the user's systemd daemon.
+        """
+
+        cmd = self.commands.user_daemon_reload(user)
+        command.prg(cmd, pty=config.debug_output)
+
+    def reload_daemon(self):
+        """
+        Reloads the systemd daemon.
+        """
+
+        cmd = self.commands.daemon_reload()
+        command.prg(cmd, pty=config.debug_output)

plugins/decman-systemd/tests/test_decman_plugins_systemd.py

@@ -0,0 +1,354 @@
+import pytest
+
+from decman.plugins import systemd as systemd_mod
+
+
+class DummyStore(dict):
+    def ensure(self, key, default):
+        if key not in self:
+            self[key] = default
+
+
+class DummyModule:
+    def __init__(self, name: str):
+        self.name = name
+        self._changed = False
+
+
+@pytest.fixture
+def store():
+    return DummyStore()
+
+
+@pytest.fixture
+def systemd():
+    return systemd_mod.Systemd()
+
+
+def test_units_decorator_sets_attribute():
+    @systemd_mod.units
+    def fn():
+        pass
+
+    assert getattr(fn, "__systemd__units__", False) is True
+
+
+def test_user_units_decorator_sets_attribute():
+    @systemd_mod.user_units
+    def fn():
+        pass
+
+    assert getattr(fn, "__systemd__user__units__", False) is True
+
+
+def test_available_true_if_systemctl_found(monkeypatch, systemd):
+    called = {}
+
+    def fake_which(name):
+        called["name"] = name
+        return "/bin/systemctl"
+
+    monkeypatch.setattr(systemd_mod.shutil, "which", fake_which)
+    assert systemd.available() is True
+    assert called["name"] == "systemctl"
+
+
+def test_available_false_if_systemctl_missing(monkeypatch, systemd):
+    monkeypatch.setattr(systemd_mod.shutil, "which", lambda name: None)
+    assert systemd.available() is False
+
+
+def test_process_modules_marks_changed_and_updates_store(monkeypatch, store, systemd):
+    # initial store empty; ensure keys will be created
+    m1 = DummyModule("mod1")
+    m2 = DummyModule("mod2")
+
+    def fake_run_method(mod, attr):
+        if mod is m1 and attr == "__systemd__units__":
+            return {"a.service"}
+        if mod is m1 and attr == "__systemd__user__units__":
+            return {"alice": {"u1.service"}}
+        # m2 has no units
+        return None
+
+    monkeypatch.setattr(systemd_mod.plugins, "run_method_with_attribute", fake_run_method)
+
+    systemd.process_modules(store, {m1, m2})
+
+    # m1 changed from default -> marked _changed
+    assert m1._changed is True
+    # m2 had no units
+    assert m2._changed is False
+
+    # enabled units aggregated
+    assert systemd.enabled_units == {"a.service"}
+    assert systemd.enabled_user_units == {"alice": {"u1.service"}}
+
+    # store updated per module
+    assert store["systemd_units_for_module"]["mod1"] == {"a.service"}
+    assert store["systemd_user_units_for_module"]["mod1"] == {"alice": {"u1.service"}}
+    assert store["systemd_units_for_module"]["mod2"] == set()
+    assert store["systemd_user_units_for_module"]["mod2"] == {}
+
+
+def test_process_modules_no_change_second_run(monkeypatch, store, systemd):
+    m1 = DummyModule("mod1")
+
+    def fake_run_method(mod, attr):
+        if attr == "__systemd__units__":
+            return {"a.service"}
+        if attr == "__systemd__user__units__":
+            return {"alice": {"u1.service"}}
+        return None
+
+    monkeypatch.setattr(systemd_mod.plugins, "run_method_with_attribute", fake_run_method)
+
+    # first run populates store
+    systemd.process_modules(store, {m1})
+    m1._changed = False
+
+    # new instance (fresh per-process in real usage)
+    systemd2 = systemd_mod.Systemd()
+    monkeypatch.setattr(systemd_mod.plugins, "run_method_with_attribute", fake_run_method)
+
+    systemd2.process_modules(store, {m1})
+
+    # values in store are same -> _changed stays False
+    assert m1._changed is False
+
+
+def test_apply_enables_and_disables_units_and_user_units(store):
+    s = systemd_mod.Systemd()
+
+    # Current enabled according to modules
+    s.enabled_units = {"new.service"}
+    s.enabled_user_units = {"alice": {"newuser.service"}}
+
+    # Store says we had an old unit enabled before
+    store["systemd_units"] = {"old.service"}
+    store["systemd_user_units"] = {"alice": {"olduser.service"}}
+
+    calls = []
+
+    def fake_reload_daemon():
+        calls.append(("reload_daemon",))
+
+    def fake_reload_user_daemon(user):
+        calls.append(("reload_user_daemon", user))
+
+    def fake_enable_units(store_arg, units_arg):
+        calls.append(("enable_units", frozenset(units_arg)))
+        store_arg["systemd_units"] |= units_arg
+
+    def fake_disable_units(store_arg, units_arg):
+        calls.append(("disable_units", frozenset(units_arg)))
+        store_arg["systemd_units"] -= units_arg
+
+    def fake_enable_user_units(store_arg, units_arg, user):
+        calls.append(("enable_user_units", user, frozenset(units_arg)))
+        store_arg["systemd_user_units"].setdefault(user, set()).update(units_arg)
+
+    def fake_disable_user_units(store_arg, units_arg, user):
+        calls.append(("disable_user_units", user, frozenset(units_arg)))
+        store_arg["systemd_user_units"].setdefault(user, set()).difference_update(units_arg)
+
+    # patch instance methods (no self parameter expected)
+    s.reload_daemon = fake_reload_daemon
+    s.reload_user_daemon = fake_reload_user_daemon
+    s.enable_units = fake_enable_units
+    s.disable_units = fake_disable_units
+    s.enable_user_units = fake_enable_user_units
+    s.disable_user_units = fake_disable_user_units
+
+    result = s.apply(store, dry_run=False, params=None)
+
+    # reloads called once
+    assert ("reload_daemon",) in calls
+    assert ("reload_user_daemon", "alice") in calls
+
+    # enable/disable correct units
+    assert ("enable_units", frozenset({"new.service"})) in calls
+    assert ("disable_units", frozenset({"old.service"})) in calls
+    assert ("enable_user_units", "alice", frozenset({"newuser.service"})) in calls
+    assert ("disable_user_units", "alice", frozenset({"olduser.service"})) in calls
+
+    # store reconciled
+    assert store["systemd_units"] == {"new.service"}
+    assert store["systemd_user_units"]["alice"] == {"newuser.service"}
+
+
+def test_apply_dry_run_does_not_mutate_store_or_call_commands(store):
+    s = systemd_mod.Systemd()
+    s.enabled_units = {"new.service"}
+    s.enabled_user_units = {"alice": {"newuser.service"}}
+
+    store["systemd_units"] = {"old.service"}
+    store["systemd_user_units"] = {"alice": {"olduser.service"}}
+
+    called = {"reload": False, "enable": False, "disable": False}
+
+    s.reload_daemon = lambda: called.__setitem__("reload", True) or True
+    s.reload_user_daemon = lambda user: called.__setitem__("reload", True) or True
+    s.enable_units = lambda st, u: called.__setitem__("enable", True) or True
+    s.disable_units = lambda st, u: called.__setitem__("disable", True) or True
+    s.enable_user_units = lambda st, u, user: called.__setitem__("enable", True) or True
+    s.disable_user_units = lambda st, u, user: called.__setitem__("disable", True) or True
+
+    result = s.apply(store, dry_run=True, params=None)
+    assert result is True
+
+    # no commands should be called
+    assert called == {"reload": False, "enable": False, "disable": False}
+
+    # store unchanged
+    assert store["systemd_units"] == {"old.service"}
+    assert store["systemd_user_units"]["alice"] == {"olduser.service"}
+
+
+def test_enable_units_success(monkeypatch, store, systemd):
+    store["systemd_units"] = {"old.service"}
+
+    def fake_run(cmd, **kwargs):
+        assert cmd[0] == "systemctl"
+        assert cmd[1] == "enable"
+        assert "new.service" in cmd[2:]
+        return 0, "ok"
+
+    monkeypatch.setattr(systemd_mod.command, "run", fake_run)
+
+    systemd.enable_units(store, {"new.service"})
+    assert store["systemd_units"] == {"old.service", "new.service"}
+
+
+def test_enable_units_failure_does_not_update_store(monkeypatch, store, systemd):
+    store["systemd_units"] = {"old.service"}
+
+    def fake_run(cmd, **kwargs):
+        return 1, "error"
+
+    monkeypatch.setattr(systemd_mod.command, "run", fake_run)
+
+    with pytest.raises(systemd_mod.errors.CommandFailedError):
+        systemd.enable_units(store, {"new.service"})
+    # unchanged
+    assert store["systemd_units"] == {"old.service"}
+
+
+def test_disable_units_success(monkeypatch, store, systemd):
+    store["systemd_units"] = {"old.service", "new.service"}
+
+    def fake_run(cmd, **kwargs):
+        assert cmd[0] == "systemctl"
+        assert cmd[1] == "disable"
+        assert "new.service" in cmd[2:]
+        return 0, "ok"
+
+    monkeypatch.setattr(systemd_mod.command, "run", fake_run)
+
+    systemd.disable_units(store, {"new.service"})
+    assert store["systemd_units"] == {"old.service"}
+
+
+def test_disable_units_failure_does_not_update_store(monkeypatch, store, systemd):
+    store["systemd_units"] = {"old.service", "new.service"}
+
+    def fake_run(cmd, **kwargs):
+        return 1, "error"
+
+    monkeypatch.setattr(systemd_mod.command, "run", fake_run)
+
+    with pytest.raises(systemd_mod.errors.CommandFailedError):
+        systemd.disable_units(store, {"new.service"})
+    assert store["systemd_units"] == {"old.service", "new.service"}
+
+
+def test_enable_user_units_success(monkeypatch, store, systemd):
+    store["systemd_user_units"] = {"alice": {"olduser.service"}}
+
+    def fake_run(cmd, **kwargs):
+        assert cmd[0] == "systemctl"
+        assert "--user" in cmd
+        assert "enable" in cmd
+        assert "newuser.service" in cmd
+        return 0, "ok"
+
+    monkeypatch.setattr(systemd_mod.command, "run", fake_run)
+
+    systemd.enable_user_units(store, {"newuser.service"}, "alice")
+    assert store["systemd_user_units"]["alice"] == {
+        "olduser.service",
+        "newuser.service",
+    }
+
+
+def test_enable_user_units_failure_does_not_update_store(monkeypatch, store, systemd):
+    store["systemd_user_units"] = {"alice": {"olduser.service"}}
+
+    def fake_run(cmd, **kwargs):
+        return 1, "error"
+
+    monkeypatch.setattr(systemd_mod.command, "run", fake_run)
+
+    with pytest.raises(systemd_mod.errors.CommandFailedError):
+        systemd.enable_user_units(store, {"newuser.service"}, "alice")
+    assert store["systemd_user_units"]["alice"] == {"olduser.service"}
+
+
+def test_disable_user_units_success(monkeypatch, store, systemd):
+    store["systemd_user_units"] = {"alice": {"olduser.service", "newuser.service"}}
+
+    def fake_run(cmd, **kwargs):
+        assert cmd[0] == "systemctl"
+        assert "--user" in cmd
+        assert "disable" in cmd
+        assert "newuser.service" in cmd
+        return 0, "ok"
+
+    monkeypatch.setattr(systemd_mod.command, "run", fake_run)
+
+    systemd.disable_user_units(store, {"newuser.service"}, "alice")
+    assert store["systemd_user_units"]["alice"] == {"olduser.service"}
+
+
+def test_disable_user_units_failure_does_not_update_store(monkeypatch, store, systemd):
+    store["systemd_user_units"] = {"alice": {"olduser.service", "newuser.service"}}
+
+    def fake_run(cmd, **kwargs):
+        return 1, "error"
+
+    monkeypatch.setattr(systemd_mod.command, "run", fake_run)
+
+    with pytest.raises(systemd_mod.errors.CommandFailedError):
+        systemd.disable_user_units(store, {"newuser.service"}, "alice")
+
+    assert store["systemd_user_units"]["alice"] == {
+        "olduser.service",
+        "newuser.service",
+    }
+
+
+def test_reload_daemon_uses_command_run(monkeypatch, systemd):
+    called = {}
+
+    def fake_run(cmd, **kwargs):
+        called["cmd"] = cmd
+        return 0, "ok"
+
+    monkeypatch.setattr(systemd_mod.command, "run", fake_run)
+    systemd.reload_daemon()
+    assert called["cmd"][:2] == ["systemctl", "daemon-reload"]
+
+
+def test_reload_user_daemon_uses_command_run(monkeypatch, systemd):
+    called = {}
+
+    def fake_run(cmd, **kwargs):
+        called["cmd"] = cmd
+        return 0, "ok"
+
+    monkeypatch.setattr(systemd_mod.command, "run", fake_run)
+    systemd.reload_user_daemon("alice")
+    cmd = called["cmd"]
+    assert cmd[0] == "systemctl"
+    assert "--user" in cmd
+    assert "daemon-reload" in cmd