This kind of cache is probably good enough for this repo (we also use it for Ormolu Live), but it has the notorious unbounded cache growth problem because nothing is ever deleted from the Cabal store. (Usually, this doesn't end up being a big problem because of a combination of sufficiently slow growth, cache expiry and manual deleting cache entries.)

I have been wanting to try out @andreabedini's https://github.com/andreabedini/cabal-cache-native that promises to do this properly, we could try it here. WDYT?

Nice idea! And TIL cabal-cache-native, I'll give it a try instead of the home cooked cache here

Unfortunately the action doesn't seem to work for our case yet: https://github.com/tweag/ghc-wasm-miso-examples/actions/runs/11872593951

Yeah, makes sense to revert to actions/cache in that case. Thanks for putting in the effort for trying it out!

No worries! The time is not wasted, given we have an extra step to generate plan.json now I'm hashing plan.json as cache key to avoid uploading the whole store each single time, let's see if that'll work

It works! I'm landing this patch. You might want to do something similar in ormolu. There's a slight downside that if plan.json doesn't change but home module source is changed, then there won't be a new cache with updated dist-newstyle and home modules may see more recompilation in ci. I think that's not a big deal though.