crewAIInc/crewAI · error · ValueError

Unsupported tar format: {format}

Error message

Unsupported tar format: {format}

What it means

Raised by FileCompressorTool._compress_tar when the requested archive format is not one of 'tar', 'tar.gz', 'tar.bz2', 'tar.xz'. The method maps format strings to tarfile mode strings via a dict; a missing key means Python's tarfile has no configured writer for that compression and the tool refuses rather than guessing a default.

Source

Thrown at lib/crewai-tools/src/crewai_tools/tools/files_compressor_tool/files_compressor_tool.py:135

            else:
                for root, _, files in os.walk(input_path):
                    for file in files:
                        full_path = os.path.join(root, file)
                        arcname = os.path.relpath(full_path, start=input_path)
                        zipf.write(full_path, arcname)

    @staticmethod
    def _compress_tar(input_path: str, output_path: str, format: str) -> None:
        """Compresses input into a tar archive with the given format."""
        format_mode = {
            "tar": "w",
            "tar.gz": "w:gz",
            "tar.bz2": "w:bz2",
            "tar.xz": "w:xz",
        }

        if format not in format_mode:
            raise ValueError(f"Unsupported tar format: {format}")

        mode = format_mode[format]

        with tarfile.open(output_path, mode) as tarf:  # type: ignore[call-overload]
            arcname = os.path.basename(input_path)
            tarf.add(input_path, arcname=arcname)

View on GitHub (pinned to 754d7323be)

Solutions

1. Use exactly one of: 'tar', 'tar.gz', 'tar.bz2', 'tar.xz'.
2. Normalize your format string before calling: fmt.lower() and expand aliases like 'tgz' -> 'tar.gz' yourself.
3. For zip output, use the tool's zip path/compression option instead of the tar path.

Example fix

# before
compress(input_path='out', output_path='a.tgz', format='tgz')

# after
compress(input_path='out', output_path='a.tar.gz', format='tar.gz')

TAR_FORMATS = {'tar','tar.gz','tar.bz2','tar.xz'}
ALIASES = {'tgz':'tar.gz','tbz2':'tar.bz2','txz':'tar.xz'}
fmt = ALIASES.get(fmt.lower(), fmt.lower())
if fmt not in TAR_FORMATS:
    raise ValueError(f'format must be one of {sorted(TAR_FORMATS)}')

def is_supported_tar_format(fmt: str) -> bool:
    return fmt.lower() in {'tar','tar.gz','tar.bz2','tar.xz'}

When it happens

Trigger: Calling the compressor with format='zip' (handled by a different code path only if the tool routes it there), format='tgz', format='tar.zst', or any variant spelling like 'tar.gzip' or 'TAR.GZ' (keys are case-sensitive).

Common situations: Users assuming any tarfile-supported compression works (tarfile also supports e.g. 'w:xz' only — zstd/lzma variants beyond the mapping do not); LLM agents shortening 'tar.gz' to 'tgz'; case or spelling drift between docs and the mapping keys.

Related errors

• Blocked unsupported tar member: {member.name!r}
• Project name '{name}' would generate folder name '{folder_na
• Project name '{name}' contains no valid characters for a Pyt
• Project name '{name}' would generate class name '{class_name
• Project name '{name}' would generate class name '{class_name

AI-assisted analysis of crewAIInc/crewAI@754d7323be (2026-08-15). Data as JSON: /api/errors/760acce4866ea33c. Report an issue: GitHub.