pip does not work with development versions of CPython due to parse error on version string

[tacaswell]

Description

The version string of development versions of CPython end with +, e.g. 3.12.3+ which causes errors in pip.

caused by #12300

Expected behavior

pip accepts the version string on the development versions of CPython.

pip version

approximately current main branch

Python version

3.12.3+ (the 3.12 branch)

OS

arch

How to Reproduce

1. install development version of CPython from 3.12 branch (but I suspect any of the 3.X branches will show this)
2. install a from a branch of pip that contains 47a8480
3. try to install anything that specifies python versions (in my case it was build)

Output

(bleeding) ~/s/p/p/build main|✓
✘ 13:41:38 [belanna] @ pip install . --no-build-isolation
Processing /home/tcaswell/source/p/pypa/build
  Preparing metadata (pyproject.toml) ... done
ERROR: Exception:
Traceback (most recent call last):
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_internal/cli/base_command.py", line 180, in exc_logging_wrapper
    status = run_func(*args)
             ^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_internal/cli/req_command.py", line 247, in wrapper
    return func(self, options, args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_internal/commands/install.py", line 377, in run
    requirement_set = resolver.resolve(
                      ^^^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_internal/resolution/resolvelib/resolver.py", line 95, in resolve
    result = self._result = resolver.resolve(
                            ^^^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers.py", line 546, in resolve
    state = resolution.resolve(requirements, max_rounds=max_rounds)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers.py", line 427, in resolve
    failure_causes = self._attempt_to_pin_criterion(name)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers.py", line 239, in _attempt_to_pin_criterion
    criteria = self._get_updated_criteria(candidate)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers.py", line 229, in _get_updated_criteria
    for requirement in self._p.get_dependencies(candidate=candidate):
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_internal/resolution/resolvelib/provider.py", line 247, in get_dependencies
    return [r for r in candidate.iter_dependencies(with_requires) if r is not None]
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_internal/resolution/resolvelib/candidates.py", line 243, in iter_dependencies
    for r in requires:
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_internal/metadata/importlib/_dists.py", line 222, in iter_dependencies
    elif not extras and req.marker.evaluate({"extra": ""}):
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_vendor/packaging/markers.py", line 252, in evaluate
    return _evaluate_markers(self._markers, current_environment)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_vendor/packaging/markers.py", line 158, in _evaluate_markers
    groups[-1].append(_eval_op(lhs_value, op, rhs_value))
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_vendor/packaging/markers.py", line 116, in _eval_op
    return spec.contains(lhs, prereleases=True)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_vendor/packaging/specifiers.py", line 568, in contains
    normalized_item = _coerce_version(item)
                      ^^^^^^^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_vendor/packaging/specifiers.py", line 36, in _coerce_version
    version = Version(version)
              ^^^^^^^^^^^^^^^^
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.12/site-packages/pip/_vendor/packaging/version.py", line 200, in __init__
    raise InvalidVersion(f"Invalid version: '{version}'")
pip._vendor.packaging.version.InvalidVersion: Invalid version: '3.12.3+'

Code of Conduct

• I agree to follow the PSF Code of Conduct.

[sbidoul]

@tacaswell do you have a dependency with a python_full_version environment marker ?

[pradyunsg]

pypa/packaging#678 (comment)

[notatallshaw]

Is this considered a blocker for pip 24.1?

uv has taken the approach of fixing up versions that are not PEP 440 compliant, in particular this is how they handle python_full_version: https://github.com/astral-sh/uv/pull/1771/files

Might it be worth applying the same on pip side for python_full_version specifically?

[sbidoul]

I have proposed pypa/packaging#802 to fix this.

[stonebig]

hello, I'm apparently maybe by this also in a constraint file:

ERROR: Invalid requirement: 'python-hdf4>=0.10.0+dummy' (from line 436 of ...\constraints.txt)

is this the same bug ? and solution ?

[sbidoul]

@stonebig this is another issue:

InvalidRequirement: Local version label can only be used with `==` or `!=` operators
    python-hdf4>=0.10.0+dummy
               ~~~~~~~~^

Pip should show the detailed error, though.