LSP-pylsp uses flake8 from system and not from the cache /bin

[valr]

Hi,
I've installed LSP-pylsp and removed all previous installation of pylsp and flake8 from my system.
After activating LSP-pylsp, it has installed pylsp and dependencies in ~/.cache/sublime-text/Package Storage/LSP-pylsp, including flake8 in the /bin directory of the cache. Then I've activated flake8 in LSP-pylsp.sublime-settings.

It seems pylsp is unable to find flake8 from the cache as I got this error message in the log:
LSP-pylsp: 2021-06-15 22:16:54,692 UTC - ERROR - pylsp.plugins.flake8_lint - Error while running flake8 '/bin/python: No module named flake8'

I've looked at the flake8_lint.py code and found that it's possible to specify the path to flake8 like this:
pylsp.plugins.flake8.executable": "~/.cache/sublime-text/Package Storage/LSP-pylsp/bin/flake8"

However it's undocumented.

I've mentioned it in the LSP chan of the ST discord and @rwols proposed the following:
"what could also work is to add $storage_path/LSP-pylsp/bin to the $PATH programmatically (in LSP-pylsp) before we start the subprocess so that pylsp (the subprocess) will favor those bundled executables"
He also mentioned: "this sounds awfully similar to #64"

Could you check if LSP-pylsp could be modified so flake8 can be used directly from the cache /bin path as proposed above?
Thanks

[rchl]

I guess the intended use of pylsp is that it's installed globally rather then per-project. So in that case using the global flake8 makes sense. I think we probably will have to override that path. Ideally internally rather than in the settings as that can be an implementation detail.

[rchl]

Should be fixed when both #67 and sublimelsp/LSP#1752 are released.

[valr]

@rchl , thank you very much!