fix: handle permissionerror during walking over tree

Previously it tried to look into 700 directories (e.g. .gnupg) which
breaks running as non-ahriman user

src/ahriman/core/utils.py

@@ -431,6 +431,22 @@ def safe_filename(source: str) -> str:
     return re.sub(r"[^A-Za-z\d\-._~:\[\]@]", "-", source)
 
 
+def safe_iterdir(path: Path) -> Iterator[Path]:
+    """
+    wrapper around :func:`pathlib.Path.iterdir`, which suppresses :exc:`PermissionError`
+
+    Args:
+        path(Path): path to iterate
+
+    Yields:
+        Path: content of the directory
+    """
+    try:
+        yield from path.iterdir()
+    except PermissionError:
+        pass
+
+
 def srcinfo_property(key: str, srcinfo: Mapping[str, Any], package_srcinfo: Mapping[str, Any], *,
                      default: Any = None) -> Any:
     """

src/ahriman/models/repository_paths.py

@@ -279,14 +279,16 @@ class RepositoryPaths(LazyLogging):
             Note, however, that this method doesn't handle any exceptions and will eventually interrupt
             if there will be any.
         """
+        from ahriman.core.utils import safe_iterdir
+
         path = path or self.root
 
         def walk(root: Path) -> Iterator[Path]:
             # basically walk, but skipping some content
-            for child in root.iterdir():
+            for child in safe_iterdir(root):
                 yield child
                 if child in (self.chroot.parent,):
-                    yield from child.iterdir()  # we only yield top-level in chroot directory
+                    yield from safe_iterdir(child)  # we only yield top-level in chroot directory
                 elif child.is_dir():
                     yield from walk(child)
 

tests/ahriman/core/test_utils.py

@@ -11,7 +11,7 @@ from unittest.mock import call as MockCall
 from ahriman.core.exceptions import BuildError, CalledProcessError, OptionError, UnsafeRunError
 from ahriman.core.utils import check_output, check_user, dataclass_view, enum_values, extract_user, filter_json, \
     full_version, minmax, package_like, parse_version, partition, pretty_datetime, pretty_interval, pretty_size, \
-    safe_filename, srcinfo_property, srcinfo_property_list, trim_package, utcnow, walk
+    safe_filename, safe_iterdir, srcinfo_property, srcinfo_property_list, trim_package, utcnow, walk
 from ahriman.models.package import Package
 from ahriman.models.package_source import PackageSource
 from ahriman.models.repository_id import RepositoryId
@@ -426,6 +426,14 @@ def test_safe_filename() -> None:
     assert safe_filename("tolua++-1.0.93-4-x86_64.pkg.tar.zst") == "tolua---1.0.93-4-x86_64.pkg.tar.zst"
 
 
+def test_safe_iterdir(mocker: MockerFixture) -> None:
+    """
+    must suppress PermissionError
+    """
+    iterdir_mock = mocker.patch("pathlib.Path.iterdir", side_effect=PermissionError)
+    assert list(safe_iterdir(Path("root"))) == []
+
+
 def test_srcinfo_property() -> None:
     """
     must correctly extract properties