Changes/GHC 8.0

GHC 8.0

Summary

Update the GHC Haskell compiler in Fedora from version 7.10 to the current stable version 8.0, with much improved support for aarch64, ppc64, and ppc64le.

Owner

• Name: Jens Petersen, Haskell_SIG
• Email: <petersen@redhat.com>, <haskell@lists.fedoraproject.org>
• Release notes owner: Simon Clark (sclark)

Current status

• Targeted release: Fedora 26
• Last updated: 2017-07-03
• Tracker bug: #1401438

Detailed Description

GHC 8.0 contains many new features, fixes, and improvements including performance. Other distros are already moving to it and Fedora users will benefit from it too. This will require updating some and rebuilding all of the Haskell packages in Fedora.

Benefit to Fedora

Fedora users will be able to use the latest stable version of the GHC Haskell compiler, and enjoy new features, bugfixes, and performance improvements.

Scope

• Proposal owners: all building work will be done in f26-ghc [done]
  • We will follow versions from latest Stackage LTS 8.2

• Other developers: Negligible work outside Haskell SIG, but the SIG can try to help resolve any issues which should arise. [done]
• Release engineering: f26-ghc needs to be created and once all rebuilding there is completed the builds need to be tagged into f26 [done]
  • List of deliverables: mostly just version bumps

• Policies and guidelines: no Haskell Packaging changes currently planned

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

Upgrade/compatibility impact

System upgrades should be smooth but users may have to update their code to make it recompile after upgrading.

How To Test

• dnf install ghc cabal-install alex happy pandoc hlint
• dnf install @haskell
• dnf install ghc-*-devel

User Experience

They will have access to GHC 8.0 in Fedora, and be able to install and use it easily.

• http://downloads.haskell.org/~ghc/8.0.1/docs/html/users_guide/8.0.1-notes.html#highlights

Dependencies

Very few packages with any Haskell dependencies outside the Haskell SIG.

Contingency Plan

• Contingency mechanism: (What to do? Who will do it?)
  • If any key packages or sufficient number can't be updated and built in time, we (owner) will drop all the partial builds in f26-ghc and revert git master branches to the current ghc-7.10 package set from F25.
• Contingency deadline: before Mass Rebuild
• Blocks release? No

Documentation

• http://downloads.haskell.org/~ghc/8.0.2/docs/html/users_guide/8.0.1-notes.html
• http://downloads.haskell.org/~ghc/8.0.2/docs/html/users_guide/8.0.2-notes.html
• https://ghc.haskell.org/trac/ghc/wiki/Migration/8.0

Release Notes

The GHC Haskell Compiler has been upgraded to version 8.0.2, and all Haskell packages rebuilt and many updated.