There is no which on windows

[cdiener]

When installing from source looking for glpk on windows the which glpsol step will fail since there is no which on windows (newer versions have where.exe which is similar).

[phantomas1234]

Hmmm, I would rather like to add "if you're on Windows, you're on your own (check out the the appveyor.yml configuration)." to the installation instructions. Do you know if one can guess the location of glpk.h on Windows? When you install glpk on windows, is glpsol automatically added to the $PATH?

[cdiener]

I would just put a try/except around subprocess... and not add anythinf to the path if there is an error. The error that there is no glpk.h is fine with me.

[Viech]

A similar issue just hit me when installing swiglpk via pip in a GitLab CI/CD environment running an Arch Linux image: https://gitlab.com/picos-api/picos/-/jobs/352226795

The problem here seems to be that /usr/bin/which is lacking from the default Arch installation as which is also a common shell built-in. Maybe this serves as another reason to detect the location differently.

[cdiener]

Hi @Viech, you can work around that by downloading GLPK into the build directory. If there is a glpk.h in the current directory setup.py won't attempt to locate glpk any further.

[Viech]

@cdiener Thanks, but there's not much of a problem for me as I can install all missing dependencies. I just found this issue when first searching for a solution and wanted to share that which is not necessarily available as a standalone binary on GNU/Linux either.