Require mandatory "--python-version" settings in mypy setup

[DonJayamanne]

From @sametmax on November 9, 2017 7:21

Environment data

VS Code version: 1.17.2
Python Extension version: latest to this date
Python Version: any
OS and version:

Actual behavior

Mypy checks the code against the version of Python it's installed in.

Expected behavior

My checks the code against the version of Python the code is written in.

More details here: python/mypy#4222 (comment)

Steps to reproduce:

• Install mypy with "python3.5 -m pip install"
• Setup and use vscode with mypy normally

Logs

Output from Python output panel

Output from Console window (Help->Developer Tools menu)

Copied from original issue: DonJayamanne/pythonVSCode#1376

[brettcannon]

Since you can manually set this in your user settings.json file today under python.linting.mypyArgs, I'm closing this as "won't fix".

[sametmax]

The ability to do it is not the important part. The important part is "mandatory". Right now I have a class full of students using vscode and mypy. They all have fake errors reported because they didn't have the setting added and were stomped. I've been using mypy for a year and learned about the settings last week. And I've been reporting bugs on mypy for a year too.

You can imagine that not only most people don't know about the settings, but they will have errors they will attribute to mypy and vscode not working.

Now I opened a ticket on the mypy issues tracker as well, but I doubt they will break compat with a mandatory settings soon. However, this issue affect users right now, and they won't be able to solve it by themself.

[brettcannon]

We are planning to rework our tool execution code soon and that might help with this (#228). At that point it will work more like running python3 -m mypy which will help make it more obvious that by default mypy and other tools are being run by the interpreter specified in your VS Code settings and not the one people just happened to install mypy under.