Error "The input line is too long" when running vcvarsall.bat in a conda environment

Hi there,

I’m facing a rather annoying issue trying to compile a C++ program in a conda environment. Usually, I would call vcvarsall.bat with right args to set up the development environment for Visual Studio. However, since I’ve updated from goanpeca/setup-miniconda@v1 to conda-incubator/setup-miniconda@v2 this no longer works and I encounter the following error:

The input line is too long.
The syntax of the command is incorrect.

You can see here a run that illustrates the problem. I’ve tried several things, such as switching to Powershell (but still need to call vcvarsall.bat via cmd), or putting the whole line into quotes, but these did not work. When I comment out the conda env from the github action then things work again, so I think the combination of conda + vcvarsall.bat is exceeding some limit in an env variable somewhere…

Any idea what might have changes between v1 and v2 that would explain the error now?

[bollwyvl]

Huzzah! Maybe we add the prefix thingy anyway, as eventually something is going to need those extra ten characters to not break for other reasons on windows.

[jaimergp]

I think we need that dir in PATH for mamba