Add other Linux distros to Github actions

[jwreep]

HYDRAD is developed primarily on a Windows machine using Cygwin, which has its own unique quirks. Github actions do not directly support testing Cygwin (only MS Visual C++), so the next best thing is to test other distros of Linux to cover our bases. This is primarily a concern with some of the non-standard C++ functions that are used in HYDRAD.

[wtbarnes]

I'm not sure I completely understand the issue here. Is the purpose to mostly test whether HYDRAD will compile on different Linux distributions? Is there an expectation that HYDRAD will behave differently on different Linux distributions? Or why one of those distributions would be a good proxy for Cygwin?

If we wanted to do this, given our current CI setup, the easiest way to do this would probably be with the "runs-on" parameter in the CI template we use: https://github-actions-workflows.openastronomy.org/en/stable/tox.html#runs-on.

[jwreep]

My thinking was that Cygwin is simply its own thing meant to mimic Linux, but since it can't be tested on Github, having a few versions of Linux is likely to cover the edge cases. Whether that's worth the extra work, I don't know. If you think it's not really important, then we could close the issue and revisit if it ever comes up again.

[wtbarnes]

We could test fairly easily on multiple versions of Ubuntu: https://github.com/actions/runner-images?tab=readme-ov-file#available-images

Additionally or alternatively, we could also periodically build wheels (and run tests) on multiple Windows and Linux architectures using manylinux which is meant to be compatible with every Linux distro: https://cibuildwheel.pypa.io/en/stable/#what-does-it-do.

Apparently there is an action for installing cygwin: https://github.com/marketplace/actions/install-cygwin-action. I don't know if this is what you were experimenting with. It would be outside of our usual CI workflow but we could set that up separately and/or have it run periodically as a cron job just to make sure we haven't really broken anything.