Add test which exercises lockfile dependency

[tommyyliu]

I was seeing the below error. I needed to install lockfile.

ImportError:
NOTE: In order to use the FileCache you must have lockfile installed.

More extensive stacktrace:
File "C:\Users\tommy.conda\envs\builder\Lib\site-packages\conda_lock\conda_lock.py", line 1341, in lock
lock_func(
File "C:\Users\tommy.conda\envs\builder\Lib\site-packages\conda_lock\conda_lock.py", line 1071, in run_lock
make_lock_files(
File "C:\Users\tommy.conda\envs\builder\Lib\site-packages\conda_lock\conda_lock.py", line 407, in make_lock_files
lock_content = lock_content | create_lockfile_from_spec(
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\tommy.conda\envs\builder\Lib\site-packages\conda_lock\conda_lock.py", line 800, in create_lockfile_from_spec
deps = _solve_for_arch(
^^^^^^^^^^^^^^^^
File "C:\Users\tommy.conda\envs\builder\Lib\site-packages\conda_lock\conda_lock.py", line 736, in _solve_for_arch
pip_deps = solve_pypi(
^^^^^^^^^^^
File "C:\Users\tommy.conda\envs\builder\Lib\site-packages\conda_lock\pypi_solver.py", line 220, in solve_pypi
pypi = PyPiRepository()
^^^^^^^^^^^^^^^^
File "C:\Users\tommy.conda\envs\builder\Lib\site-packages\conda_lock_vendor\poetry\repositories\pypi_repository.py", line 72, in init
self._cache_control_cache = FileCache(str(release_cache_dir / "_http"))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\tommy.conda\envs\builder\Lib\site-packages\cachecontrol\caches\file_cache.py", line 87, in init
raise ImportError(notice)
ImportError:
NOTE: In order to use the FileCache you must have
lockfile installed. You can install it via pip:
pip install lockfile

[mariusvniekerk]

what does your source file look like?

[tommyyliu]

Created a more minimal repro:

channels:
    - conda-forge
dependencies:
    - python=3.10
    - pip:
          - pypylon

It seems like the pip resolution requires lockfile.
"conda install lockfile" fixes it.
Additionally, I'm trying this on Windows. I can try on a different OS later if that helps.

[maresb]

Thanks a lot for the report! This should now be fixed by conda-forge/conda-lock-feedstock#40.

We still need to add test coverage for this type of pip resolution. I appreciate your minimal reproducer, we should add it or something similar into the test suite.

[maresb]

According to my debugger, we do have coverage of Poetry's usage of FileCache in our test suite, e.g. test_run_lock_with_pip. I think there's nothing more to do here.