langchain-ai/deepagents · error · ExtrasIntrospectionError

Distribution {distribution_name!r} not found; cannot preserv

Error message

Distribution {distribution_name!r} not found; cannot preserve already-installed extras safely

What it means

`get_optional_dependency_status` looks up the installed distribution's metadata (to parse its `Requires-Dist` extras markers). If the named distribution is not installed and `strict=True`, it raises `ExtrasIntrospectionError` because it cannot safely preserve already-installed extras without the metadata. With `strict=False` it only logs a warning and returns empty status.

Source

Thrown at libs/code/deepagents_code/extras_info.py:1257

            reliably.

    Returns:
        Sorted tuple of optional extra statuses. An empty tuple is returned
            when the distribution itself is not found.

    Raises:
        ExtrasIntrospectionError: If `strict` is `True` and metadata
            introspection fails.
    """
    try:
        dist = distribution(distribution_name)
    except PackageNotFoundError:
        if strict:
            msg = (
                f"Distribution {distribution_name!r} not found; cannot preserve "
                "already-installed extras safely"
            )
            raise ExtrasIntrospectionError(msg) from None
        # Editable installs renamed by the user, dev checkouts without metadata,
        # or vendored copies all hit this path. The dependency screen otherwise
        # silently renders "none detected" twice; warn so the cause is visible.
        logger.warning(
            "Distribution %s not found; optional-dependency status will be empty",
            distribution_name,
        )
        return ()

    own_name = distribution_name.lower()
    installed: dict[str, list[tuple[str, str]]] = {}
    missing: dict[str, list[str]] = {}
    for raw in dist.requires or []:
        try:
            req = Requirement(raw)
        except InvalidRequirement:
            if strict:
                msg = (

View on GitHub (pinned to a1af029e6e)

Solutions

1. Install the missing distribution (e.g. `pip install langchain-quickjs` or `pip install -e .[extra]`)
2. Pass `strict=False` if a missing distribution is acceptable and you only need best-effort status
3. Verify the distribution name matches the installed metadata (`pip show <name>` / `importlib.metadata.distribution(name)`

Example fix

// before
status = get_optional_dependency_status("langchain-quickjs", strict=True)

// after
try:
    status = get_optional_dependency_status("langchain-quickjs", strict=True)
except ExtrasIntrospectionError:
    status = EMPTY_STATUS  # or reinstall the distribution

from importlib.metadata import distribution
try:
    distribution("langchain-quickjs")
except Exception:
    # distribution absent; skip strict introspection
    pass

from importlib.metadata import distribution, PackageNotFoundError
def is_installed(name: str) -> bool:
    try:
        distribution(name); return True
    except PackageNotFoundError:
        return False

try:
    status = get_optional_dependency_status(dist, strict=True)
except ExtrasIntrospectionError:
    status = {}  # degrade to best-effort

When it happens

Trigger: Calling `get_optional_dependency_status(..., strict=True)` for a distribution name that `importlib.metadata` cannot find — the package isn't installed, was renamed, or is an editable/dev checkout without dist-info metadata.

Common situations: User renamed an editable install directory; running from a vendored copy without packaging metadata; checking an extra of a package that was pip-uninstalled while dcode still references it; wrong distribution name passed (e.g. `dcode` vs actual dist name).

Related errors

• Could not parse optional-dependency metadata; cannot preserv
• Cannot determine location for {package_root}
• uv tool receipt contains invalid extras on the tool requirem
• uv tool receipt contains duplicate canonical extra names
• Extra {extra!r} is a base dependency and cannot be removed.

AI-assisted analysis of langchain-ai/deepagents@a1af029e6e (2026-08-29). Data as JSON: /api/errors/e1f2e9b785e85f4a. Report an issue: GitHub.