[Haskell-cafe] Haskell CI with many repositories/packages

[Jeroen Bransen]

Hi cafe,

Does anyone know of a good setup for doing continuous integration with a 
set of Haskell packages, each in its own repository? Just building 
everything upon every commit is not so hard, but to speed up building 
times I'd like to build and test only the minimal set of packages. In 
particular, at a commit for some package A, I would like to build and 
test A and all packages that depend on A.

The problem is that most CI tools use some notion of 'build artefact', 
which Stack doesn't really seem to give me. Ideally building a package 
results in some object file, which can then be used by the other 
packages. When building failed, packages that depend on it can still use 
the last succesful build. I've tried to look up some Haskell projects, 
but most of them seem to use some ad hoc setup.

Some pointers are appreciated, as we are using Gitlab a gitlab-runner 
specific option would be great, but I am also open to use Jenkins or 
other tools. And I guess my main struggle now is on the stack/Haskell side.

Regards,
Jeroen Bransen