Seems we have a problem. The issue I stumbled upon earlier when testing with the single container seems to be reproducible. I'm gonna see if I can reproduce this locally with the alpine image as well.

EDIT: Seems this is caused by the fact that the container runs as root so tests that check for permissions will always fail because... root :)

Finally, a working version! 🎉

I resorted to creating a dedicated GitHub Action as the most elegant solution.

You can remove the go mod cache action as it's useless now, an action container doesn't have access to the host go modules dir.

Ah it seems that you can mount host dirs https://stackoverflow.com/questions/58997638/docker-container-volume-does-not-get-mounted-in-github-actions

Yes, if you expand the build step in the log you'll see exactly which directories are mounted inside the container from the host. The home dir is one of them.

@relu if you look at the make test output for this PR, you'll see that it downloads all go modules, so as it is, the container doesn't have the go cache in the right place.

I'll look into it, I didn't realize it was not using the cache.

Ok, so I was wrong, it does not mount the actual home dir in the container but rather this location: /home/runner/work/_temp/_github_home. So we can instruct the cache to read/write from there instead of the regular home dir.

EDIT: Should be good now. I actually had to force set the GOPATH, I suspect the way the default value is set does not make use of the $HOME env var, but rather using a lower-level method (directly from /etc/passwd).