Changes/Haskell GHC 9.6 and Stackage 22

Haskell GHC 9.6 and Stackage LTS 22

This is a proposed Change for Fedora Linux.
This document represents a proposed Change. As part of the Changes process, proposals are publicly announced in order to receive community feedback. This proposal will only be implemented if approved by the Fedora Engineering Steering Committee.

Summary

Update the GHC Haskell compiler from major version 9.4 to 9.6 and Haskell packages from Stackage LTS 21 to LTS 22 versions.

Owner

• Name: Jens Petersen
• Email: <petersen@redhat.com>

Current status

• Targeted release: Fedora Linux 40
• Last updated: 2023-12-22
• Announced
• Discussion thread
• FESCo issue: <will be assigned by the Wrangler>
• Tracker bug: <will be assigned by the Wrangler>
• Release notes tracker: <will be assigned by the Wrangler>

Detailed Description

For Fedora 40, the main GHC Haskell compiler package will be updated from version 9.4.5 to the latest stable 9.6.3 or newer bugfix release (rebasing the ghc package with the ghc9.6 package). Along with this, Haskell packages in Stackage (the stable Haskell source package distribution) will be updated from the versions in LTS 21 to latest LTS 22 release. Haskell packages not in Stackage will be updated to the latest appropriate version in the upstream Hackage package repository.

Benefit to Fedora

Fedora users will have the latest stable Haskell compiler release, package tools, and current Haskell packages from latest Stackage LTS.

GHC 9.6.3 is the latest current stable version of GHC with various enhancements and fixes (see the release notes linked in the Documentation section for more details about new features and improvements in 9.6).

Scope

• Proposal owners:
  • update rawhide ghc9.4 is build against itself
  • rebase ghc to 9.6.3
  • refresh packagings with the latest cabal-rpm release if needed
  • update packages to latest Stackage LTS 22 versions using cabal-rpm
  • build all the packages in a Koji sidetag repo in dependency order using fbrnch
  • push the sidetag through Bodhi to rawhide
  • deal with obsoleting ghc9.6 if needed

• Other developers: no actions should be needed

• Release engineering: #Releng issue number

• Policies and guidelines: N/A (not needed for this Change)

• Trademark approval: N/A (not needed for this Change)

• Alignment with Community Initiatives: N/A

Upgrade/compatibility impact

Any dropped packages will have obsoletes added. Otherwise there should not be any direct upgrade impact.

Users' Haskell projects will get built with ghc-9.6 when they next build them and might need some minor code tweaks (see the release notes linked below).

How To Test

• install ghc and cabal-install
• install pandoc, ShellCheck, ghcid, git-annex, hadolint, stack, xmonad, Agda
• install ghc-*-devel or ghc-*-prof or ghc-*-doc
• cabal-rpm builddep <favouritepackage>; cabal install <favouritepackage>
• install ghc8.10, ghc9.0, ghc9.2, ghc9.4, or ghc*devel
• test upgrades of F39 Haskell packages to F40

User Experience

Users will have the most recent stable major version of ghc and Haskell libraries and tools available to them. This makes it easier to build the latest versions of Haskell projects.

In particular cabal-install will also be updated from 3.8 to 3.10, pandoc will be updated to 3.1, and stack to 2.13.

Contingency Plan

• Contingency mechanism:
  • Change owner will drop the new builds and revert dist-git back to the versions in F39
• Contingency deadline: Beta Freeze
• Blocks release? No

Documentation

• https://downloads.haskell.org/~ghc/9.6.3/docs/html/users_guide/9.6.1-notes.html