pypa/pip · error · NoneMetadataError

None {metadata_name} metadata found for distribution: {dist}

Error message

None {metadata_name} metadata found for distribution: {dist}

What it means

Error "None {metadata_name} metadata found for distribution: {dist}" thrown in pypa/pip.

Source

Thrown at src/pip/_internal/metadata/pkg_resources.py:212

        return parse_version(self._dist.version)

    @property
    def raw_version(self) -> str:
        return self._dist.version

    def is_file(self, path: InfoPath) -> bool:
        return self._dist.has_metadata(str(path))

    def iter_distutils_script_names(self) -> Iterator[str]:
        yield from self._dist.metadata_listdir("scripts")

    def read_text(self, path: InfoPath) -> str:
        name = str(path)
        if not self._dist.has_metadata(name):
            raise FileNotFoundError(name)
        content = self._dist.get_metadata(name)
        if content is None:
            raise NoneMetadataError(self, name)
        return content

    def iter_entry_points(self) -> Iterable[BaseEntryPoint]:
        try:
            entry_map = self._dist.get_entry_map()
        except ValueError as e:
            raise InstallationError(
                f"Error parsing entry points for {self.raw_name}: {e}"
            ) from e
        for group, entries in entry_map.items():
            for name, entry_point in entries.items():
                name, _, value = str(entry_point).partition("=")
                yield EntryPoint(name=name.strip(), value=value.strip(), group=group)

    def _metadata_impl(self) -> email.message.Message:
        """
        :raises NoneMetadataError: if the distribution reports `has_metadata()`
            True but `get_metadata()` returns None.

View on GitHub (pinned to d7d0d0a394)

When it happens

Trigger: Thrown at src/pip/_internal/metadata/pkg_resources.py:212 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of pypa/pip@d7d0d0a394 (2026-08-04). Data as JSON: /data/errors/f5ae6b3df6222588.json. Report an issue: GitHub.