Preparing for coming Stackage major version bumps

The Stackage team is starting to prepare for the coming Stackage LTS 21 release (which will be based off current ghc-9.4 nightly) and shortly afterwards bumping Stackage Nightly to ghc-9.6.

Now is a great chance to check if your packages are in Stackage Nightly (before lts-21 branches) and also if they can build with the ghc-9.6 core library versions.

So please help us to help you by opening a stackage PR to enable your packages under ghc-9.4 (for 9.6, initial bounds detection should be automatic with our tooling).


Hi @juhp in the past you’ve opened issues in my package repos to tell me that my package was failing to build in Stackage. Thanks for taking the time to do that, I really appreciate it.

In the future when you talk to neglectful maintainers you might consider referring them to the Haskell GitHub Trust as a long-term maintenance option.


Hi @jamesbrock, ideally we would open upstream tickets, but when doing ghc major upgrades the number of affected packages is too large and we don’t have automation for it - for packages against your github account mentioned in stackage you should receive a github notification in the related 9.6 Stackage issues I opened at least.

However there will inevitably be some build failures etc and we don’t have a fast way to inform maintainers of such disabling of packages. Though we would welcome help with notification tooling.

(I don’t think Haskell Trustees have the bandwidth to handle this volume of changes at all, though they may assist in some specific cases, where packages are holding up the ecosystem.)


@juhp thank you for your work! Question: is there any place on the internet where i can track the progress towards the new LTS? GitHub milestone or something. I’m curious about approximate timeline for it.

Commenting here, since I havent seen anyone mention it yet:

LTS 21 has been released, on 9.4, with nightlt updated to use GHC 9.6! Thanks to the Stackage team for all your hard work!


@artem there was this issue: Please create LTS 21 for ghc-9.4 · Issue #355 · commercialhaskell/lts-haskell · GitHub

1 Like