No module named 'pip._internal.metadata' for version 2.3.1

[HitLuca]

For some obscure reason my CI pipeline started to break as soon as I updated my pip-check-reqs package from version 2.3.0 to version 2.3.1.
I am running a standard pip-missing-reqs command, in a pipenv environment using python==3.7 and pip==21.2.4.

My output from that command is:

+ pip-missing-reqs $PROJECT_FOLDER
Traceback (most recent call last):
  File "/usr/local/bin/pip-missing-reqs", line 5, in <module>
    from pip_check_reqs.find_missing_reqs import main
  File "/usr/local/lib/python3.7/site-packages/pip_check_reqs/find_missing_reqs.py", line 17, in <module>
    from pip_check_reqs import common
  File "/usr/local/lib/python3.7/site-packages/pip_check_reqs/common.py", line 18, in <module>
    from pip._internal.metadata import get_default_environment, get_environment
ModuleNotFoundError: No module named 'pip._internal.metadata'

Reverting the package version to 2.3.0 seems to solve the issue

[MrMino]

Same here. To my knowledge, two PRs were merged in that version #68 and #72. The former one (mine) was a minuscule change that isn't related as far as I can tell.

[MrMino]

My suspicion was true: #72 was made as a replacement, without a fallback for earlier versions of pip. Fixed that inside the MR above.