nektos/act compatibility

[ruby0b]

It's nice to be able to test github CI locally without pushing to some remote.
https://github.com/nektos/act makes this possible but due to an issue with the actions/cache action haskell-ci won't work out of the box with it (nektos/act#285).

The workaround is simply guarding the cache step using if: ${{ !env.ACT }} as mentioned in nektos/act#285 (comment).
Including this would make act work without having to manually edit the CI file generated by haskell-ci and tracking down the workaround in the first place.

[phadej]

I'm not a fan. Why cannot act be taught to skip (or mock) actions/cache steps. That would solve issue for all.

I don't want to keep track of third party things, there are already enough.

[ruby0b]

Yeah that's fair, I agree.

For future reference:

1. I did find an act issue for fixing actions/cache: Enhancement: Automatically disable unsupported cache actions nektos/act#989
2. That issue is not actually why the cache step fails in this case though. The caching should just not do anything and output a warning. The reason it fails is that act does not auto-install node when using container:. (See Issue: exec: "node": executable file not found in $PATH: unknown nektos/act#973 (comment))

So for now you're probably best off adding if: ${{ !env.ACT }} to the cache action whenever you want to run act (and invoking act -r to reuse the container).