gh-138432: zoneinfo: improve error message for PathLike relative paths

Lib/test/test_zoneinfo/test_zoneinfo.py

@@ -1784,6 +1784,7 @@ def test_reset_tzpath_relative_paths(self):
             ("/usr/share/zoneinfo", "../relative/path",),
             ("path/to/somewhere", "../relative/path",),
             ("/usr/share/zoneinfo", "path/to/somewhere", "../relative/path",),
+            (pathlib.Path("path/to/somewhere"),)
         ]
         for input_paths in bad_values:
             with self.subTest(input_paths=input_paths):

Lib/zoneinfo/_tzpath.py

@@ -57,7 +57,7 @@ def _parse_python_tzpath(env_var, stacklevel):
 
 
 def _get_invalid_paths_message(tzpaths):
-    invalid_paths = (path for path in tzpaths if not os.path.isabs(path))
+    invalid_paths = (os.fspath(path) for path in tzpaths if not os.path.isabs(path))
 
     prefix = "\n    "
     indented_str = prefix + prefix.join(invalid_paths)

Misc/NEWS.d/next/Library/2025-09-03-15-20-10.gh-issue-138432.RMc7UX.rst

@@ -0,0 +1,4 @@
+:meth:`zoneinfo.reset_tzpath` will now raise ``ValueError`` if it encounters
+an :class:`os.PathLike` object representing a relative path, along with a
+more informative error message. It previously raised ``TypeError`` in this
+case.