
The GHC developers are very pleased to announce the availability of the second release candidate of GHC 9.6.7. Binary distributions, source distributions, and documentation are available at https://downloads.haskell.org/ghc/9.6.7-rc2 We hope to have this release available via ghcup shortly. Haskell Language Server does not yet build with GHC 9.6.7. See the note below. If all goes according to plan, we expect that the final release of GHC 9.6.7 will be available on February 28. Release candidate 2 contains the following changes relative to (the unannounced) release candidate 1: - the symbol atomic_inc64 is no longer exported from the RTS GHC 9.6.7 will bring a number of fixes, including: - GHC’s internal Unique type has been widened to 64-bits on 32-bit architectures, avoiding potential miscompilations on large projects. - Fix a runtime crash when using the compacting GC, caused by black holes in large objects. - Added new flags -fspec-eval and -fspec-eval-dictfun to allow switching off speculative evaluation. The following libraries have been updated since GHC 9.6.6: - base-4.18.3.0 (the version number in the rc2 release notes is incorrect) - filepath-1.4.301.0 - unix-2.8.6.0 - bytestring-0.11.5.4 - array-0.5.8.0 A more detailed description can be found in the [release notes] and a full list of changes in [GHC!13841] and [GHC!13891] Note about Haskell Language Server and building GHC 9.8+: The change of Unique to 64 bit [GHC#22010] adds the exported symbol ghc_unique_counter64 to the RTS. Unfortunately it's impossible to avoid this without breaking other things. If you encounter a linker error related to ghc_unique_counter64 when building GHC (or building a GHC-derived package like ghc-lib-parser) with GHC 9.6.7, you probably have to add this [fix] to the program you're building. At the time of writing all released GHC 9.8 versions are affected, as well as the latest version of ghc-lib-parser-9.8 on hackage (which is a dependency of Haskell Language Server). We would like to thank GitHub, IOG, the Zw3rk stake pool, Well-Typed, Tweag I/O, Serokell, Equinix, SimSpace, the Haskell Foundation, and other anonymous contributors whose on-going financial and in-kind support has facilitated GHC maintenance and release management over the years. Finally, this release would not have been possible without the hundreds of open-source contributors whose work comprise this release. Please give this release candidate a try and open a [ticket] if you see anything amiss. ~ Luite [release notes]: https://downloads.haskell.org/ghc/9.6.7-rc2/docs/users_guide/9.6.7-notes.htm... [GHC!13841]: https://gitlab.haskell.org/ghc/ghc/-/merge_requests/13841 [GHC!13891]: https://gitlab.haskell.org/ghc/ghc/-/merge_requests/13891 [GHC#22010]: https://gitlab.haskell.org/ghc/ghc/-/issues/22010 [fix] https://gitlab.haskell.org/ghc/ghc/-/merge_requests/13743 [ticket] https://gitlab.haskell.org/ghc/ghc/-/issues/new P.S. Apologies if you already received this mail.

Thanks Luite, I want to try to build the RC at least - just noting the RC version number is not ideal (since 9.6.7.20250131 > 9.6.7 - we don't really have a great versioning scheme for snapshots...) Cheers, Jens

I haven't actually run it yet, but from building it the only major thing I
noticed so far is:
- Hadrian requires 'directory' newer than both current ghc-9.8 and ghc-9.10
😢 (as new as 9.12) - I would expect hadrian in 9.6 to be buildable with
9.6's 'directory', etc.
I can probably workaround it for Fedora (a bit tedious) but it feels
excessive: the overall trend that hadrian is getting harder and harder to
build without cabal-install in particular.
Jens
On Wed, 26 Feb 2025 at 18:33, Jens Petersen
Thanks Luite,
I want to try to build the RC at least - just noting the RC version number is not ideal (since 9.6.7.20250131 > 9.6.7 - we don't really have a great versioning scheme for snapshots...)
Cheers, Jens
participants (2)
-
Jens Petersen
-
Luite Stegeman