pytest-dev/pytest · error · NotImplementedError

XXX win32

Error message

XXX win32

What it means

The Stat.owner property returns the owning username by calling pwd.getpwuid on the file's uid. On Windows there is no pwd module and no Unix uid concept, so the property raises NotImplementedError('XXX win32') at the top of the method. This is a known platform limitation of the legacy py.path.local API. The message is a placeholder indicating the feature was never implemented for Windows.

Source

Thrown at src/_pytest/_py/path.py:222

    if TYPE_CHECKING:

        @property
        def size(self) -> int: ...

        @property
        def mtime(self) -> float: ...

    def __getattr__(self, name: str) -> Any:
        return getattr(self._osstatresult, "st_" + name)

    def __init__(self, path, osstatresult):
        self.path = path
        self._osstatresult = osstatresult

    @property
    def owner(self):
        if iswin32:
            raise NotImplementedError("XXX win32")
        import pwd

        entry = error.checked_call(pwd.getpwuid, self.uid)  # type:ignore[attr-defined,unused-ignore]
        return entry[0]

    @property
    def group(self):
        """Return group name of file."""
        if iswin32:
            raise NotImplementedError("XXX win32")
        import grp

        entry = error.checked_call(grp.getgrgid, self.gid)  # type:ignore[attr-defined,unused-ignore]
        return entry[0]

    def isdir(self):
        return S_ISDIR(self._osstatresult.st_mode)

View on GitHub (pinned to 0d6fbdeffa)

Solutions

1. Use pathlib + os module cross-platform: on Windows, owner resolution needs pywin32 or ctypes calls (GetFileSecurity).
2. Skip the ownership assertion on Windows: `if sys.platform != 'win32': assert stat.owner == expected`.
3. Use pytest.skip on Windows for tests that exercise Unix ownership semantics.

Example fix

# before
assert path.stat().owner == 'beagle'
# after
import sys, pytest
if sys.platform == 'win32':
    pytest.skip('owner not supported on Windows')
assert path.stat().owner == 'beagle'

import sys
def can_resolve_owner() -> bool:
    return sys.platform != 'win32' and getattr(sys, 'platform', '') != 'win32'
# usage
if can_resolve_owner():
    assert path.stat().owner == expected_owner
else:
    # Windows: owner not supported by py.path.local
    pass

import sys
def supports_unix_owner() -> bool:
    return sys.platform != 'win32'

When it happens

Trigger: Calling path.stat().owner on Windows (sys.platform == 'win32' or os._name == 'nt'). Triggered at Stat.owner (src/_pytest/_py/path.py:219-222). On POSIX this code path is never reached.

Common situations: Running a test suite that worked on Linux/macOS on a Windows CI runner; asserting ownership in cross-platform tests; legacy py.path.local code that assumed Unix.

Related errors

• no {name!r} checker available for {self.path!r}
• can only pass None, Path instances or non-empty strings to L
• {relpath!r}: not a string or path object
• Don't know how to compute {hashtype!r} hash
• invalid specification {kw!r}

AI-assisted analysis of pytest-dev/pytest@0d6fbdeffa (2026-08-11). Data as JSON: /api/errors/f7252532f07b0565. Report an issue: GitHub.