python-poetry/poetry · warning · ValueError

Environment " " does not exist.</warning>

Error message

<warning>Environment "{name}" does not exist.</warning>

What it means

Raised as ValueError in EnvManager.remove when the interpreter probe succeeded and Poetry computed the expected venv name (base_env_name + '-py' + minor) but that directory does not exist under virtualenvs_path. The env was expected for the discovered python version but is absent.

Solutions

1. Check 'poetry env list' to see which envs actually exist for this project.
2. If using in-project venvs, remove the .venv directory manually instead.
3. Confirm virtualenvs_path config matches where envs were created.
4. Treat as informational if the env is already gone - nothing to remove.

Example fix

// before
manager.remove("3.12")  # no myproject-py3.12 dir exists -> ValueError

// after - remove a version that has an env
manager.remove("3.11")

from pathlib import Path

def expected_venv_exists(manager, python_version: str) -> bool:
    from poetry.core.constraints.version import Version
    v = Version.parse(python_version)
    minor = f"{v.major}.{v.minor}"
    name = f"{manager.base_env_name}-py{minor}"
    return (manager._poetry.config.virtualenvs_path / name).exists()

def is_missing_env_value_error(e: Exception) -> bool:
    return isinstance(e, ValueError) and 'does not exist' in str(e)

try:
    manager.remove("3.12")
except ValueError as e:
    if 'does not exist' in str(e):
        # no env for this version - nothing to remove
        pass
    else:
        raise

When it happens

Trigger: Calling 'poetry env remove <python-version-or-interpreter>' where the version resolves correctly but no venv directory '{base_env_name}-py{minor}' exists (env_manager.py:339-343).

Common situations: Asking to remove a python version's env that was never created; the env was already removed; the venv was created in-project (virtualenvs.in-project=true) so nothing lives in virtualenvs_path; virtualenvs_path was changed/relocated.

Related errors

• Environment " " does not exist.</warning>
• Env doesn't belong to this project.
• Command errored with the following return code
• Command errored with the following return code
• Discovered shell ' ' doesn't have an activator in virtual…

AI-assisted analysis of python-poetry/poetry@92b74dcfe3 (2026-08-04). Data as JSON: /api/errors/777dd1616ac96168. Report an issue: GitHub.

Appendix: source

Thrown at src/poetry/utils/env/env_manager.py:343

            pass

        try:
            python_version_string = subprocess.check_output(
                [python, "-c", GET_PYTHON_VERSION_ONELINER],
                text=True,
                encoding="locale",
            )
        except CalledProcessError as e:
            raise EnvCommandError(e)

        python_version = Version.parse(python_version_string.strip())
        minor = f"{python_version.major}.{python_version.minor}"

        name = f"{self.base_env_name}-py{minor}"
        venv_path = venv_path / name

        if not venv_path.exists():
            raise ValueError(f'<warning>Environment "{name}" does not exist.</warning>')

        if self.envs_file.exists():
            self.envs_file.remove_section(self.base_env_name, minor)

        self.remove_venv(venv_path)

        return VirtualEnv(venv_path, venv_path)

    def use_in_project_venv(self) -> bool:
        in_project: bool | None = self._poetry.config.get("virtualenvs.in-project")
        if in_project is not None:
            return in_project

        return self.in_project_venv.is_dir()

    def in_project_venv_exists(self) -> bool:
        in_project: bool | None = self._poetry.config.get("virtualenvs.in-project")
        if in_project is False:

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