Is your feature request related to a problem? Please describe.

We have unofficial(?) support for Cabal, but it often breaks in trivial ways because the core developers generally don’t use it and there is nothing to ensure it gets updated.

Describe the solution you'd like

A non-required GitHub check that builds with Cabal to check that it works. I don’t think a failing build should stop a PR, since we don’t need devs to spend their time figuring out how to update a build system they don’t use. But can we alert some specific volunteers who care about Cabal when it fails?

I think if we have CI, it could also be good to move cabal.project to the standard location (or at least document why it’s in contrib – which could be as simple as “This file is in contrib/ to convey that it’s not an officially supported build tool, although we do make an effort to keep it current.”)

Describe alternatives you've considered

Indicate clearly in the docs & cabal.project file exactly how unsupported Cabal is “it’s likely to be broken from time to time, but we’re open to PRs that remedy that”.

Make Cabal completely unsupported by removing the cabal.project.

I’m not a fan of either of these, especially since Cabal is the de facto tool for so much in the Haskell ecosystem.