November 2025 - Glasgow-haskell-users

GHC 9.12.3-rc2 is now available
by Zubin Duggal 12 Nov '25

12 Nov '25

The GHC developers are very pleased to announce the availability of the second release candidate for GHC 9.12.3. Binary distributions, source distributions, and documentation are available at [downloads.haskell.org][] and via [GHCup](https://www.haskell.org/ghcup/). GHC 9.12.3 is a bug-fix release fixing several issues of a variety of severities and scopes. A full accounting of these fixes can be found in the [release notes][]. As always, GHC's release status, including planned future releases, can be found on the GHC Wiki [status][]. This release candidate will have a two-week testing period. If all goes well the final release will be available the week of 24 November 2025. The changes from the first release candidate are * Fix a regression resulting in a panic with empty cases (#26442, #25960). * Fix for a potential segfault in the bytecode interpreter (#23210). * Fix for a regression with tabs not being allowed in string gaps (#26415). * Fix for a crash with the non-moving GC (#26204). * A rework of how internal symbols used by the code-generator are handled to adapt to changes in the Apple toolchain, enabling this release to bootstrap on macOS 26 Tahoe (#26166). GHC development is sponsored by: * [Juspay](https://juspay.com/) * [QBayLogic](https://qbaylogic.com/) * [Channable](https://www.channable.com/) * [Haskell Foundation](https://haskell.foundation/) * [Serokell](https://serokell.io/) * [Well-Typed](https://well-typed.com/) * [Tweag](https://www.tweag.io/) * [Dotcom-Monitor](https://www.dotcom-monitor.com/) * [LoadView](https://www.loadview-testing.com/) * [Web Hosting Buddy](https://webhostingbuddy.com/) * [Find My Electric](https://www.findmyelectric.com/) * [Standard Chartered](https://www.sc.com) * [UpCloud](https://upcloud.com) We would like to that these sponsors and other anonymous contributors whose on-going financial and in-kind support has facilitated GHC maintenance and release management over the years. Finally, this release would not have been possible without the hundreds of open-source contributors whose work comprise this release. As always, do give this release a try and open a [ticket][] if you see anything amiss. [release notes]: https://gitlab.haskell.org/ghc/ghc/-/blob/ghc-9.12/docs/users_guide/9.12.3-… [status]: https://gitlab.haskell.org/ghc/ghc/-/wikis/GHC-status [downloads.haskell.org] https://downloads.haskell.org/ghc/9.12.3-rc2 [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new

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GHC 9.14.1-rc2 is now available
by Zubin Duggal 07 Nov '25

07 Nov '25

The GHC developers are very pleased to announce the availability of the second release candidate of GHC 9.14.1. Binary distributions, source distributions, and documentation are available at [downloads.haskell.org][]. The changes from the first release candidate are: * Bump the exceptions submodule to 0.10.11 * Bump the os-string submodule to 2.0.8 * Fix a driver regression causing an infinite loop with cyclic imports GHC 9.14 will bring a number of new features and improvements, including: * Significant improvements in specialisation: * The `SPECIALISE` pragma now allows use of type application syntax * The `SPECIALISE` pragma can be used to specialise for expression arguments as well as type arguments. * Specialisation is now considerably more reliable in the presence of `newtype`s * Significant GHCi improvements including: * Correctness and performance improvements in the bytecode interpreter * Features in the GHCi debugger * Support for multiple home units in GHCi * Implementation of the [Explicit Level Imports proposal][levels] * `RequiredTypeArguments` can now be used in more contexts * SSE/AVX2 support in the x86 native code generator backend * A major update of the Windows toolchain and improved compatibility with macOS Tahoe * ... and many more A full accounting of changes can be found in the [release notes][]. Given the many specialisation improvements and their potential for regression, we would very much appreciate testing and performance characterisation on downstream workloads. Note that while this release makes many improvements in the specialisation optimisation, polymorphic specialisation will remain disabled by default in the final release due to concern over regressions of the sort identified in [#26329][T26329]. Users needing more aggressive specialisation can explicitly enable this feature with the `-fpolymorphic-specialisation` flag. Depending upon our experience with 9.14.1, we may enable this feature by default in a later minor release. We would like to thank the Zw3rk stake pool, Well-Typed, Mercury, Channable, Tweag I/O, Serokell, SimSpace, the Haskell Foundation, and other anonymous contributors whose on-going financial and in-kind support has facilitated GHC maintenance and release management over the years. Finally, this release would not have been possible without the hundreds of open-source contributors whose work have made the Haskell ecosystem what it is today. As always, do give this release a try and open a [ticket][] if you see anything amiss. [downloads.haskell.org] https://downloads.haskell.org/ghc/9.14.1-rc2 [release notes]: https://downloads.haskell.org/ghc/9.14.1-rc2/docs/users_guide/9.14.1-notes.… [ticket]: https://gitlab.haskell.org/ghc/homepage/-/issues/new [macos]: https://gitlab.haskell.org/ghc/ghc/-/issues/26166 [T26329]: https://gitlab.haskell.org/ghc/ghc/-/issues/26329 [levels]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0682-e…

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Re: [Haskell-cafe] Re: GHC 9.14.1-rc2 is now available
by George Colpitts 06 Nov '25

06 Nov '25

solved it for me also. thanks! On Thu, Nov 6, 2025 at 12:44 PM Noon van der Silk <noonsilk(a)gmail.com> wrote: > Success. > > On Thu, 6 Nov 2025 at 16:41, Zubin Duggal <zubin(a)well-typed.com> wrote: > >> Try refreshing https://downloads.haskell.org/ghc/9.14.1-rc2/, >> I purged the CDN cache. >> >> On 25/11/06 12:34, George Colpitts wrote: >> >I get a 404 Not Found when I click on any of the darwin releases, e.g. >> > >> https://downloads.haskell.org/ghc/9.14.1-rc2/ghc-9.14.0.20251031-aarch64-ap… >> > >> >On Thu, Nov 6, 2025 at 12:12 PM Zubin Duggal <zubin(a)well-typed.com> >> wrote: >> > >> >> The GHC developers are very pleased to announce the availability of the >> >> second release candidate of GHC 9.14.1. Binary distributions, source >> >> distributions, and documentation are available at [ >> downloads.haskell.org >> >> ][]. >> >> >> >> The changes from the first release candidate are: >> >> >> >> * Bump the exceptions submodule to 0.10.11 >> >> * Bump the os-string submodule to 2.0.8 >> >> * Fix a driver regression causing an infinite loop with cyclic imports >> >> >> >> GHC 9.14 will bring a number of new features and improvements, >> including: >> >> >> >> * Significant improvements in specialisation: >> >> * The `SPECIALISE` pragma now allows use of type application syntax >> >> * The `SPECIALISE` pragma can be used to specialise for expression >> >> arguments >> >> as well as type arguments. >> >> * Specialisation is now considerably more reliable in the presence >> of >> >> `newtype`s >> >> >> >> * Significant GHCi improvements including: >> >> * Correctness and performance improvements in the bytecode >> interpreter >> >> * Features in the GHCi debugger >> >> * Support for multiple home units in GHCi >> >> >> >> * Implementation of the [Explicit Level Imports proposal][levels] >> >> >> >> * `RequiredTypeArguments` can now be used in more contexts >> >> >> >> * SSE/AVX2 support in the x86 native code generator backend >> >> >> >> * A major update of the Windows toolchain and improved compatibility >> with >> >> macOS Tahoe >> >> >> >> * ... and many more >> >> >> >> A full accounting of changes can be found in the [release notes][]. >> Given >> >> the >> >> many specialisation improvements and their potential for regression, we >> >> would >> >> very much appreciate testing and performance characterisation on >> downstream >> >> workloads. >> >> >> >> Note that while this release makes many improvements in the >> specialisation >> >> optimisation, polymorphic specialisation will remain disabled by >> default >> >> in the >> >> final release due to concern over regressions of the sort identified in >> >> [#26329][T26329]. Users needing more aggressive specialisation can >> >> explicitly >> >> enable this feature with the `-fpolymorphic-specialisation` flag. >> Depending >> >> upon our experience with 9.14.1, we may enable this feature by default >> in a >> >> later minor release. >> >> >> >> We would like to thank the Zw3rk stake pool, Well-Typed, Mercury, >> >> Channable, >> >> Tweag I/O, Serokell, SimSpace, the Haskell Foundation, and other >> anonymous >> >> contributors whose on-going financial and in-kind support has >> facilitated >> >> GHC >> >> maintenance and release management over the years. Finally, this >> release >> >> would >> >> not have been possible without the hundreds of open-source contributors >> >> whose >> >> work have made the Haskell ecosystem what it is today. >> >> >> >> As always, do give this release a try and open a [ticket][] if you see >> >> anything amiss. >> >> >> >> >> >> [downloads.haskell.org] https://downloads.haskell.org/ghc/9.14.1-rc2 >> >> [release notes]: >> >> >> https://downloads.haskell.org/ghc/9.14.1-rc2/docs/users_guide/9.14.1-notes.… >> >> [ticket]: https://gitlab.haskell.org/ghc/homepage/-/issues/new >> >> [macos]: https://gitlab.haskell.org/ghc/ghc/-/issues/26166 >> >> [T26329]: https://gitlab.haskell.org/ghc/ghc/-/issues/26329 >> >> [levels]: >> >> >> https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0682-e… >> >> _______________________________________________ >> >> Glasgow-haskell-users mailing list -- >> glasgow-haskell-users(a)haskell.org >> >> To unsubscribe send an email to >> glasgow-haskell-users-leave(a)haskell.org >> >> >> _______________________________________________ >> Haskell-Cafe mailing list -- haskell-cafe(a)haskell.org >> To (un)subscribe, modify options or view archives go to: >> Only members subscribed via the mailman list are allowed to post. > > > > -- > Noon van der Silk > > http://silky.github.io/ > > "My programming language is kindness." >

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