Close IO objects

[sanmai-NL]

Pull Request Checklist

• A news fragment is added in news/ describing what is new.
• Test cases added for changed code.

Describe what you have changed in this PR.

Close file handles. Attempt to fix e.g., these warnings.

$ pdm lock --production
python.use_venv is on, creating a virtualenv for this project...
/usr/lib/python3.11/subprocess.py:1127: ResourceWarning: subprocess 76 is still running
  _warn("subprocess %s is still running" % self.pid,
ResourceWarning: Enable tracemalloc to get the object allocation traceback
/usr/lib/python3.11/subprocess.py:1127: ResourceWarning: subprocess 75 is still running
  _warn("subprocess %s is still running" % self.pid,
ResourceWarning: Enable tracemalloc to get the object allocation traceback
/usr/lib/python3.11/subprocess.py:1127: ResourceWarning: subprocess 77 is still running
  _warn("subprocess %s is still running" % self.pid,
ResourceWarning: Enable tracemalloc to get the object allocation traceback
sys:1: ResourceWarning: unclosed file <_io.BufferedReader name=4>
sys:1: ResourceWarning: unclosed file <_io.BufferedReader name=6>
sys:1: ResourceWarning: unclosed file <_io.BufferedReader name=3>
sys:1: ResourceWarning: unclosed file <_io.BufferedReader name=9>
sys:1: ResourceWarning: unclosed file <_io.BufferedReader name=7>
sys:1: ResourceWarning: unclosed file <_io.BufferedReader name=11>
Virtualenv is created successfully at /opt/templatepython/.venv

[frostming]

Oh thanks, does it fix all the warnings you pasted in the OP?

[sanmai-NL]

@frostming There are more warnings when using PYTHONDEVMODE=1 (#2004) than the one listed, warnings of various nature. I still need to look into how PDM's automated tests work and how to invoke the CLI. If you have any pointers, they'd be welcome.

[frostming]

@sanmai-NL That part definitely needs help! Thanks for your contribution.

BTW, do you think it would help if we manually close the files mentioned in #1971 ?