GHC 9.12.4 is now available

Ambrose: > How fast do releases make it into nixpkgs? It seems that for recent releases we have been reasonably quick in preparing and merging the update change. The main delays here are associated with doing test builds on my own hardware which takes a while (since I usually try to build a few packages with a non trivial dependency tree) and the availability of reviewers familiar with GHC. I’ve also had releases come at a bad time in the past which delayed things further. * 9.10.3 2-3 days * 9.14.1 3 days * 9.12.3 3 days * 9.12.4 2 days With Nixpkgs, this doesn’t mean availability after 2-3 days though, since there are additional delays associated with how the NixOS/Nixpkgs channels update (all builds have to finish and certain checks to pass) which generally means a few days. Updating the GHC version which is used to build all Haskell based packages in Nixpkgs takes multiple weeks, mainly because pandoc has become popular enough as a tool for dealing with package documentation that the entirety of Nixpkgs (indirectly) depends on pandoc. A change to the default GHC causes a rebuild of pandoc which causes a rebuild of the entirety of Nixpkgs. For this reason, I usually try to merge a mere addition of the GHC version which makes it available to users who explicitly look for it as quickly as possible and perform any default version updates later. This also gives time for any bugs in the release to come apparent on development branches. This is just an informal report of how I’ve been doing things, not an official policy, guarantee or statement of intent. My main goal is keeping everything Haskell-related in Nixpkgs as maintainable as possible since bus factor is already an issue as things stand. andreasabel: > delay the announcements of new GHC versions here until they become available with ghcup I don’t see why, as GHCup is just a distribution channel like others. In the past, I’ve frequently first heard about a GHC release from the E-Mail release announcement, I imagine it’s similar for other GHC package maintainers. If this was delayed until GHCup had the chance to update its channels, it may well further delay the update in other distribution channels.