Setting up CI for Guile

[Wilfred Hughes]

Hi folks

I'm a big fan of CI (automated testing), and maybe you are too. I'd
love to have CI for reviewing patches of Guile.

So, I decided to set it up! This isn't something that's available on
GNU Savannah, so I've used GitLab (which is still FSF-approved Free
Software).

You can see my different branches being tested here:
https://gitlab.com/wilfred/guile/pipelines?scope=branches

Guile compilation is slow: 3 hours 15 minutes on my feeble laptop.
GitLab's CI only gives you an hour.

I solved this by creating a Docker image:
https://gitlab.com/wilfred/guile-build-image that contains a recent
checkout of Guile that has been built. This allows me to do an
incremental build in GitLab, which is much faster (5-10 minutes,
including tests).

What do you think? I'd love this to become the standard way to
contribute: it's easy to see what patches are in need of review, and
whether tests pass after a given patch is applied.

In any case, I'm finding it very helpful, maybe you will find so too.

Cheers
Wilfred