F35 Change: GHC 8.10 and Stackage lts-18 (Self-Contained Change proposal)

[Ben Cotton]

https://fedoraproject.org/wiki/Changes/GHC_8.10_%26_Stackage_18

== Summary ==
The GHC Haskell compiler will be updated from major version 8.8 to 8.10,
and Haskell packages will be updated from Stackage LTS 16 to LTS 18 versions.

== Owner ==
* Name: [[User:Petersen| Jens Petersen]] (Haskell SIG)
* Email: <petersen(a)redhat.com&gt;


== Detailed Description ==
For Fedora 35, the GHC Haskell compiler will be updated from version
8.8.4 to the latest stable 8.10.5 release (rebasing from the ghc:8.10
module stream).
Along with this, Haskell packages in [https://www.stackage.org
Stackage] (the stable Haskell source package distribution) will be
updated from the versions in LTS 16 to latest LTS 18 release.
Haskell packages not in Stackage will be updated to the latest
appropriate version in the upstream [https://hackage.haskell.org
Hackage] package repository.

On the s390x architecture, ghc-8.10 now supports the llvm backend,
which should improve s390x performance significantly.


== Benefit to Fedora ==
Fedora users will benefit from access to the latest stable Haskell
compiler release, package tools, and current stable Haskell packages
from Stackage LTS.

GHC 8.10 features performance improvements, new language extension
features, and bugfixes (see the release notes linked in the
Documentation section for more details).

== Scope ==
* Proposal owners:
** rebase ghc to 8.10.5
** update ghc-rpm-macros to the final version for F35 [done]
** refresh packagings with the latest cabal-rpm release
** update packages to latest [https://www.stackage.org/lts-18.1
Stackage LTS 18.1] versions using cabal-rpm
** build all the packages in a Koji sidetag repo in dependency order
** When finished push all builds through Bodhi to Rawhide before the
mass rebuild

* Release engineering: N/A
* Policies and guidelines: N/A (not needed for this Change)
* Trademark approval: N/A (not needed for this Change)

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

Users' Haskell projects will get rebuilt with ghc-8.10 when they next
build them and might need small tweaks.

== How To Test ==
* install ghc and cabal-install
* install pandoc, ShellCheck, git-annex
* install ghc-*-devel or ghc-*-prof or ghc-*-doc
* cabal-rpm builddep <favouritepackage>; cabal install <favouritepackage>
* test upgrades of F34 Haskell packages to F35

== 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 be updated from 3.0 to 3.2 and
`stack` from 2.3 to 2.7.

== Dependencies ==
(not provided)

== Contingency Plan ==
* Contingency mechanism: (What to do?  Who will do it?)
** Change owner will drop the new builds and revert back to the versions in F34.
* Contingency deadline: Beta Freeze

== Documentation ==
https://downloads.haskell.org/~ghc/8.10.5/docs/html/users_guide/8.10.1-no...


-- 
Ben Cotton
He / Him / His
Fedora Program Manager
Red Hat
TZ=America/Indiana/Indianapolis