https://github.com/python/cpython/commit/d8a9466e29f59f81aacf1959b835862bcd47b731 commit: d8a9466e29f59f81aacf1959b835862bcd47b731 branch: main author: Petr Viktorin <[email protected]> committer: encukou <[email protected]> date: 2025-08-18T13:53:01+02:00 summary:
bpo-38735: Don't fail when importing from / with sys.pycache_prefix set (GH-30456) Co-authored-by: Serhiy Storchaka <[email protected]> files: A Misc/NEWS.d/next/Library/2022-01-07-16-56-57.bpo-38735.NFfJX6.rst M Lib/importlib/_bootstrap_external.py M Lib/test/test_importlib/test_util.py diff --git a/Lib/importlib/_bootstrap_external.py b/Lib/importlib/_bootstrap_external.py index 8bcd741c446bd2..8a1437a2cc5d1e 100644 --- a/Lib/importlib/_bootstrap_external.py +++ b/Lib/importlib/_bootstrap_external.py @@ -297,7 +297,8 @@ def cache_from_source(path, debug_override=None, *, optimization=None): # Strip initial drive from a Windows path. We know we have an absolute # path here, so the second part of the check rules out a POSIX path that # happens to contain a colon at the second character. - if head[1] == ':' and head[0] not in path_separators: + # Slicing avoids issues with an empty (or short) `head`. + if head[1:2] == ':' and head[0:1] not in path_separators: head = head[2:] # Strip initial path separator from `head` to complete the conversion diff --git a/Lib/test/test_importlib/test_util.py b/Lib/test/test_importlib/test_util.py index 6d6d5f96aab4a8..a77ce234deec58 100644 --- a/Lib/test/test_importlib/test_util.py +++ b/Lib/test/test_importlib/test_util.py @@ -580,6 +580,18 @@ def test_cache_from_source_respects_pycache_prefix_relative(self): self.util.cache_from_source(path, optimization=''), os.path.normpath(expect)) + @unittest.skipIf(sys.implementation.cache_tag is None, + 'requires sys.implementation.cache_tag to not be None') + def test_cache_from_source_in_root_with_pycache_prefix(self): + # Regression test for gh-82916 + pycache_prefix = os.path.join(os.path.sep, 'tmp', 'bytecode') + path = 'qux.py' + expect = os.path.join(os.path.sep, 'tmp', 'bytecode', + f'qux.{self.tag}.pyc') + with util.temporary_pycache_prefix(pycache_prefix): + with os_helper.change_cwd('/'): + self.assertEqual(self.util.cache_from_source(path), expect) + @unittest.skipIf(sys.implementation.cache_tag is None, 'requires sys.implementation.cache_tag to not be None') def test_source_from_cache_inside_pycache_prefix(self): diff --git a/Misc/NEWS.d/next/Library/2022-01-07-16-56-57.bpo-38735.NFfJX6.rst b/Misc/NEWS.d/next/Library/2022-01-07-16-56-57.bpo-38735.NFfJX6.rst new file mode 100644 index 00000000000000..7f4ea04284e10b --- /dev/null +++ b/Misc/NEWS.d/next/Library/2022-01-07-16-56-57.bpo-38735.NFfJX6.rst @@ -0,0 +1,2 @@ +Fix failure when importing a module from the root directory on unix-like +platforms with sys.pycache_prefix set. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
