Release for ghc-8.6.1

[mpickering]

This issue is to track progress towards releasing a version of proto-lens which is compatible with ghc-8.6.1 which will be released in the next few days.

[judah]

I just tried a quick hack to the repo's stack.yaml to see where the build currently fails:

https://gist.github.com/judah/02672a86ba65852e5a57fbefd65767bb

Some packages (both dependencies and proto-lens-*) need bounds to be bumped, which I assume will happen after the actual release of 8.6.1. Notably, polyparse which is used transitively by haskell-src-exts also needs an update due to how MonadFail works.

Log: https://gist.github.com/judah/02672a86ba65852e5a57fbefd65767bb

[mpickering]

haskell-src-exts is my responsibility but like you say, I can't do a release until polyparse is updated.

[mpickering]

I just released haskell-src-exts-1.20.3 which is compatible with ghc-8.6.1.

[judah]

Update: I've created a branch (ghc-8.6) for this task, which mostly works: https://github.com/google/proto-lens/compare/ghc-8.6?expand=1

However, this requires using some dependencies that aren't released yet (e.g. tagged, contravariant), and a couple local packages still aren't built (proto-lens-benchmarks and proto-lens-discrimination) due to dependencies that haven't been upgraded yet.

At this point I'm planning to wait another couple weeks for the dependencies to get updated and released.

[mpickering]

Thanks Judah. That will be enough for me to get started.

[judah]

I've released proto-lens-0.4.0.1 (and related versions of the other packages) which are all compatible with ghc-8.6.1.