python-poetry/poetry · error · GroupNotFoundError

Group(s) not found: {', '.join(message_parts)}

Error message

Group(s) not found: {', '.join(message_parts)}

What it means

`GroupNotFoundError` from `_validate_group_options` (group_command.py:117-134) when a dependency group passed to `--with`, `--without`, or `--only` is not declared in `pyproject.toml` (neither `[tool.poetry.group.<g>]` nor `[dependency-groups]`). Poetry validates group names against `package.has_dependency_group` before operating.

Source

Thrown at src/poetry/console/commands/group_command.py:134

    def _validate_group_options(self, group_options: dict[str, set[str]]) -> None:
        """
        Raises an error if it detects that a group is not part of pyproject.toml
        """
        invalid_options = defaultdict(set)
        for opt, groups in group_options.items():
            for group in groups:
                if not self.poetry.package.has_dependency_group(group):
                    invalid_options[group].add(opt)
        if invalid_options:
            message_parts = []
            for group in sorted(invalid_options):
                opts = ", ".join(
                    f"<fg=yellow;options=bold>--{opt}</>"
                    for opt in sorted(invalid_options[group])
                )
                message_parts.append(f"{group} (via {opts})")
            raise GroupNotFoundError(f"Group(s) not found: {', '.join(message_parts)}")

View on GitHub (pinned to 92b74dcfe3)

Solutions

1. List declared groups with `poetry show --tree` or inspect `[tool.poetry.group]` / `[dependency-groups]` in pyproject.toml.
2. Correct the flag to an existing group name.
3. If the group should exist, declare it in pyproject.toml first.

Example fix

# before
poetry install --with doc
# after
poetry install --with docs

from poetry.factory import Factory
poetry = Factory().create_poetry()
groups = set(poetry.package.dependency_group_names())
requested = {"docs", "test"}
missing = requested - groups
if missing:
    raise SystemExit(f"unknown groups: {sorted(missing)}")

def group_exists(poetry, name: str) -> bool:
    return poetry.package.has_dependency_group(name)

When it happens

Trigger: Running `poetry install --with docs` when no `docs` group exists; `--without ci` when there is no `ci` group; typos in group names.

Common situations: Renaming a group in pyproject but forgetting CI flags; assuming a group exists because the directory does; mixing PEP 735 `[dependency-groups]` and legacy `[tool.poetry.group]` names.

Related errors

• Setting {self.argument('key')} does not exist
• You can only pass one value.
• You can only add optional dependencies to the main group
• You must pass exactly 1 value
• "{value}" is an invalid value for {key}

AI-assisted analysis of python-poetry/poetry@92b74dcfe3 (2026-08-04). Data as JSON: /data/errors/105c7b37dad7560c.json. Report an issue: GitHub.