PR: Remove check_path to allow running in debugger

[maurerle]

Description of Changes

PYTHONPATH entries are removed on start, resulting in a the warning shown on check_path in requirements - program does not start.
Removing pythonpath was added to disable shadowed base libraries, but I think thats exactly how the PYTHONPATH could and would behave.
Still it makes sense to remove them so that it does not create problems.

Yet the resulting warning
"Spyder must be installed properly (e.g. from source: 'python setup.py install'), or directory 'dir' must be in PYTHONPATH environment variable."
is not helpful and is removed through this PR

I would therefore not remove entries on PYTHONPATH from PATH

Affirmation

By submitting this Pull Request or typing my (user)name below,
I affirm the Developer Certificate of Origin
with respect to all commits and content included in this PR,
and understand I am releasing the same under Spyder's MIT (Expat) license.

I certify the above statement is true and correct: Florian Maurer

[ccordoba12]

Hey @maurerle, I don't agree with this change. We remove PYTHONPATH in start.py to protect Spyder from crashing at startup when, for instance, a user adds to PYTHONPATH a module named random.py or string.py, which is not uncommon.

You also said:

PYTHONPATH entries are removed on start, resulting in a the warning shown on check_path in requirements - program does not start.

The way you need to start Spyder when developing it is by running python bootstrap.py in terminal, as explained in our Contributing guide. That makes a lot of adjustments necessary for development (like installing Spyder and our subrepos in external-deps in development mode). So, if you're starting Spyder in a different way, please resort back to this mechanism, which is used by the entire development team.

[maurerle]

So I sometimes debug Spyder (like with the actual debugger) using VSCode, that way:

conda create -n spyder python=3.10
cd spyder
pip install -e .[test]

Then select the newly created python interpreter from spyder environment and hit F5 to debug the bootstrap.py command.
This runs /usr/bin/env /opt/conda/envs/spyder/bin/python /home/maurer/.vscode-o ss/extensions/ms-python.python-2022.18.2/pythonFiles/lib/python/debugpy/adapter/../../debugpy/launcher 43327 -- /home/maurer/gitea/spyder/bootstrap.py

And in that situation I am getting here:

So you might say that that way is not supported and i should rather run something like python -m debugpy --listen 43327 bootstrap.py and attach my debugger to that process but in this case the message is not very helpful, as my PYTHONPATH is correct?

[ccordoba12]

Ok, I see. Then please check what happens if you remove the call to check_path in mainwindow.py. It shouldn't be necessary anymore.

[maurerle]

Yes, that works too, great.
I updated my PR accordingly.

The check was introduced in 1f73f2f - I did not find which case it was meant to handle, but it is already 12 years ago.

[ccordoba12]

Looks good to me now, thanks @maurerle!

[ccordoba12]

The check was introduced in 1f73f2f - I did not find which case it was meant to handle, but it is already 12 years ago.

Until a few months ago we injected the git clone Spyder directory into sys.path, but now we install Spyder in development mode. So, that check is not necessary anymore.