gh-93461: Invalidate sys.path_importer_cache entries with relative paths

Author: tiran

Lib/importlib/_bootstrap_external.py

@@ -1399,7 +1399,9 @@ def invalidate_caches():
         """Call the invalidate_caches() method on all path entry finders
         stored in sys.path_importer_caches (where implemented)."""
         for name, finder in list(sys.path_importer_cache.items()):
-            if finder is None:
+            # Drop entry if finder name is a relative path. The current
+            # working directory may have changed.
+            if finder is None or not _path_isabs(name):
                 del sys.path_importer_cache[name]
             elif hasattr(finder, 'invalidate_caches'):
                 finder.invalidate_caches()

Misc/NEWS.d/next/Core and Builtins/2022-06-09-19-19-02.gh-issue-93461.5DqP1e.rst

@@ -0,0 +1,3 @@
+:func:`importlib.invalidate_caches` now drops entries from
+:data:`sys.path_importer_cache` with a relative path as name. This solves a
+caching issue when a process changes its current working directory.