zoneinfo: improve error message for PathLike relative paths

Author: tungol

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)