pypa/pip · error · InvalidSdistFilename

Invalid sdist filename (empty project name): {filename!r}

Error message

Invalid sdist filename (empty project name): {filename!r}

What it means

Raised by parse_sdist_filename() when the project-name portion (everything before the last dash) is empty (utils.py:356-359). This happens when the stem starts with a dash, e.g. '-1.0', so rpartition('-') returns ('', '-', '1.0') with an empty name_part.

Source

Thrown at src/pip/_vendor/packaging/utils.py:357

    .. _Source distribution format: https://packaging.python.org/specifications/source-distribution-format/#source-distribution-file-name
    """
    if filename.endswith(".tar.gz"):
        file_stem = filename[: -len(".tar.gz")]
    elif filename.endswith(".zip"):
        file_stem = filename[: -len(".zip")]
    else:
        raise InvalidSdistFilename(
            f"Invalid sdist filename (extension must be '.tar.gz' or '.zip'):"
            f" {filename!r}"
        )

    # We are requiring a PEP 440 version, which cannot contain dashes,
    # so we split on the last dash.
    name_part, sep, version_part = file_stem.rpartition("-")
    if not sep:
        raise InvalidSdistFilename(f"Invalid sdist filename: {filename!r}")
    if not name_part:
        raise InvalidSdistFilename(
            f"Invalid sdist filename (empty project name): {filename!r}"
        )

    name = canonicalize_name(name_part)

    try:
        version = Version(version_part)
    except InvalidVersion as e:
        raise InvalidSdistFilename(
            f"Invalid sdist filename (invalid version): {filename!r}"
        ) from e

    return (name, version)

View on GitHub (pinned to f399c37189)

Solutions

1. Ensure the project name is non-empty and appears before the version in the filename.
2. Rename the file to include a valid project name: {name}-{version}.tar.gz.
3. Validate filenames from external sources before parsing.

Example fix

// before
parse_sdist_filename('-1.0.tar.gz')
// after
parse_sdist_filename('foo-1.0.tar.gz')

def safe_parse_sdist(filename: str):
    stem = filename[:-7] if filename.endswith(".tar.gz") else filename[:-4]
    name_part, sep, version_part = stem.rpartition("-")
    if not name_part:
        raise ValueError(f"Sdist filename has empty project name: {filename!r}")
    return parse_sdist_filename(filename)

def has_nonempty_sdist_name(filename: str) -> bool:
    if not isinstance(filename, str):
        return False
    if filename.endswith(".tar.gz"):
        stem = filename[:-7]
    elif filename.endswith(".zip"):
        stem = filename[:-4]
    else:
        return False
    name_part, sep, _ = stem.rpartition("-")
    return bool(sep) and bool(name_part)

from packaging.utils import InvalidSdistFilename

try:
    name, ver = parse_sdist_filename(filename)
except InvalidSdistFilename as e:
    if "empty project name" in str(e):
        logger.error("Sdist filename starts with a dash: %s", filename)
    raise

When it happens

Trigger: A filename whose stem begins with a dash, e.g. parse_sdist_filename('-1.0.tar.gz') where the name part before the last dash is empty.

Common situations: A malformed filename produced by a buggy build tool, or a manually constructed filename where the project name was accidentally omitted.

Related errors

• Invalid sdist filename {package.sdist.filename!r}
• Invalid project name: {filename!r}
• Invalid sdist filename (extension must be '.tar.gz' or '.zip
• Invalid sdist filename: {filename!r}
• Invalid sdist filename (invalid version): {filename!r}

AI-assisted analysis of pypa/pip@f399c37189 (2026-08-08). Data as JSON: /api/errors/60305c6676125bef. Report an issue: GitHub.