Support custom mypy path

[achimnol]

In a monorepo setting using Pantsbuild, various Python tools are installed in separate virtaulenvs like:

• dist/export/python/virtualenvs/mypy/3.12.6/bin/mypy
• dist/export/python/virtualenvs/ruff/3.12.6/bin/ruff

while the main source tree looks at (while it is also possible to have per-subdir lock files):

• dist/export/python/virtualenvs/python-default/3.12.6/bin/python

I can override the --python-executable argument passed to mypy for the main virtualenv, but I cannot override the mypy executable path itself. It seems to be hardcoded here:

https://github.com/python-lsp/pylsp-mypy/blob/9be427d3346c15e5e7ab331d4a312e5a83477cee/pylsp_mypy/plugin.py#L307-L313

Could we make it something configurable?

[Richardk2n]

This is in no way hardcoded. These lines just mean "pick whatever mypy is on PATH", which can easily be changed by changing PATH.

If you can propose a way to make it configurable, that does not present a significant security risk, I am open to it. Simply providing a config option would mean, that a malicious repo could make you execute malicious code by opening its source files in your editor.

[achimnol]

I have multiple Python projects to work on, where each project have distinct configurations:

• mypy is embedded in the virtualenv
• mypy should be taken from a special location like the above case

Technically it is possible to switch PATH using something like direnv, but it becomes quickly cumbersome to do so in Zed, Neovim, VSCode, etc.

[achimnol]

Also, the sibling ruff plugin support the custom executable path as mentioned in the PR. Why not adding this? 😉

[Richardk2n]

Another plugin having a security issue does not compel me to include one in mine.

The newest commit contains an option how you can risk your computer without endangering others.