Support for GHC-9.12.x?

[mouse07410]

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

GHC-9.12.1 has been around for a while, and 9.12.2 is on the horizon. It would be nice to have HLS supporting these.

Describe the solution you'd like

Added support for GHC-9.12.x. Current master doesn't seem to work because of (at least?) two dependent packages failing to compile under 9.12.1:

• ghc-exactprint-1.10.0.0
• ormolu-0.7.7.0

Describe alternatives you've considered

There's no alternative, except for downgrading GHC to 9.10.1. Which is not that attractive for those living on the "bleeding edge". ;-)

[eldritch-cookie]

For ghc-exactprint a version is compatible with only one major version of GHC so 1.10.0.0 only works with GHC 9.10.x
but the solution is simple just upgrade to 1.12.0.0,
however given that it is a major version upgrade it is highly likely there will be breakages that need to be fixed.
Regarding ormolu there is a newer version that has a built with that claims compability with GHC 9.12.1 which i am inclined to believe as the latest fourmolu can in fact be compiled on GHC 9.12.1

[fendor]

There will not be binaries for 9.12.1, as the GHC 9.12.1 release is broken.

However, we are actively working on 9.12.2 support as soon as it releases.

[sohang3112]

There will not be binaries for 9.12.1, as the GHC 9.12.1 release is broken.

@fendor Can you please clarify, how is GHC 9.12.1 release "broken"?

[jhrcek]

In general you can find the list of issues via GHC status page.
GHC 9.12.1 in particular has some "incorrect runtime result" issues: https://gitlab.haskell.org/ghc/ghc/-/milestones/405#tab-issues

[fendor]

@sohang3112 I am referring to the issue https://gitlab.haskell.org/ghc/ghc/-/issues/25653. There was also this announcement: https://discourse.haskell.org/t/psa-correctness-issue-in-ghc-9-12/11204