pypa/pip · error · PylockSelectError

python_full_version {env_python_full_version!r} in provided

Error message

python_full_version {env_python_full_version!r} in provided environment does not satisfy the Python version requirement {str(self.requires_python)!r}

What it means

Raised as PylockSelectError (pylock.py:801) by Pylock.select() when the lock-level requires-python specifier set is not satisfied by python_full_version of the selection environment. It is the first guard inside select(): if the whole lock requires Python >=3.10 and you select for 3.9, it fails before any package logic runs.

Source

Thrown at src/pip/_vendor/packaging/pylock.py:801

            ),
        )
        env_python_full_version = (
            environment["python_full_version"]
            if environment
            else default_environment()["python_full_version"]
        )

        # #. Check if the metadata version specified by :ref:`pylock-lock-version` is
        #    supported; an error or warning MUST be raised as appropriate.
        # Covered by lock.validate() which is a precondition for this method.

        # #. If :ref:`pylock-requires-python` is specified, check that the environment
        #    being installed for meets the requirement; an error MUST be raised if it is
        #    not met.
        if self.requires_python and not self.requires_python.contains(
            env_python_full_version,
        ):
            raise PylockSelectError(
                f"python_full_version {env_python_full_version!r} "
                f"in provided environment does not satisfy the Python version "
                f"requirement {str(self.requires_python)!r}"
            )

        # #. If :ref:`pylock-environments` is specified, check that at least one of the
        #    environment marker expressions is satisfied; an error MUST be raised if no
        #    expression is satisfied.
        if self.environments:
            for env_marker in self.environments:
                if env_marker.evaluate(
                    cast("dict[str, str]", environment or {}), context="requirement"
                ):
                    break
            else:
                raise PylockSelectError(
                    "Provided environment does not satisfy any of the "
                    "environments specified in the lock file"

View on GitHub (pinned to d7d0d0a394)

Solutions

Switch to a Python interpreter whose full version satisfies the lock's requires-python.
Pass an explicit environment dict whose python_full_version satisfies requires-python, if you are selecting for a different target than the host.
Loosen requires-python in the lock (only if you control it and it is actually compatible).

Example fix

# before: lock says requires-python = ">=3.11"; host is 3.10
pylock.select()

# after
pylock.select(environment={'python_full_version': '3.11.6',
                            'python_version': '3.11',
                            'os_name': 'posix',
                            'sys_platform': 'linux'})

Defensive patterns

Strategy: validation

Validate before calling

from pip._vendor.packaging.specifiers import SpecifierSet
def env_satisfies_lock_python(requires_python, python_full_version):
    return (not requires_python) or SpecifierSet(requires_python).contains(python_full_version)

Type guard

null

Try / catch

from pip._vendor.packaging.pylock import PylockSelectError
try:
    list(pylock.select(environment=env))
except PylockSelectError as e:
    if 'requires-python' in str(e) or 'Python version requirement' in str(e):
        switch_interpreter_or_env(e)

Prevention

Pass an explicit environment dict that matches your target interpreter.
Keep the lock's requires-python aligned with the interpreters you actually run.

When it happens

Trigger: Calling pylock.select(environment={'python_full_version': '3.9.1', ...}) on a lock whose [root] requires-python = '>=3.10'. Also triggered when environment is omitted and default_environment()['python_full_version'] (the running interpreter) violates requires-python.

Common situations: CI runs the lock on a different Python than the author used. A user omits the environment argument and the host Python is older than the lock allows. Cross-platform lock installed under the wrong interpreter.

Related errors

AI-assisted analysis of pypa/pip@d7d0d0a394 (2026-08-04). Data as JSON: /data/errors/5f48006131f66afd.json. Report an issue: GitHub.