- ghc-releases - Haskell.org

Boot libraries for GHC 10.0
by Zubin Duggal 02 Apr '26

02 Apr '26

Hi all, The GHC 10.0 branch is scheduled to be cut next week. You are receiving this email because you are listed as a maintainer on a boot library or have uploaded a version to hackage recently. Below are the current versions of all boot libraries and submodules in the GHC tree. Libraries behind Hackage: - file-io: 0.1.5 in tree, 0.2.0 on Hackage - filepath: 1.5.4.0 in tree, 1.5.5.0 on Hackage - os-string: 2.0.8 in tree, 2.0.10 on Hackage - process: 1.6.26.1 in tree, 1.6.27.0 on Hackage Unless there are objections, we will attempt to bump these four libraries to their latest Hackage versions before the fork. Libraries currently at the latest Hackage version: - Cabal 3.16.1.0 - Cabal-syntax 3.16.1.0 - Win32 2.14.2.1 - array 0.5.8.0 - binary 0.8.9.3 - bytestring 0.12.2.0 - containers 0.8 - deepseq 1.5.2.0 - directory 1.3.10.1 - exceptions 0.10.12 - haskeline 0.8.4.1 - hpc 0.7.0.2 - hsc2hs 0.68.10 - libffi-clib 3.5.2 - mtl 2.3.2 - parsec 3.1.18.0 - pretty 1.1.3.6 - semaphore-compat 1.0.0 - stm 2.5.3.1 - template-haskell-lift 0.1.0.0 - template-haskell-quasiquoter 0.1.0.0 - terminfo 0.4.1.7 - text 2.1.4 - time 1.15 - transformers 0.6.3.0 - unix 2.8.8.0 - xhtml 3000.4.0.0 I presume there will also be a corresponding Cabal 3.18 release, which we will coordinate with the Cabal developlers. Otherwise, if you would like a different version of any library to ship with GHC 10.0, please open a GHC ticket at https://gitlab.haskell.org/ghc/ghc/-/issues/new so we can track it. Thanks, Zubin

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GHC 9.12.4 is now available
by Zubin Duggal 27 Mar '26

27 Mar '26

The GHC developers are very pleased to announce the release of GHC 9.12.4. Binary distributions, source distributions, and documentation are available at [downloads.haskell.org][] and via [GHCup](https://www.haskell.org/ghcup/). GHC 9.12.4 is a bug-fix release fixing many issues of a variety of severities and scopes, including: * Fixed a critical code generation regression where sub-word division produced incorrect results (#26711, #26668), similar to the bug fixed in 9.12.2 * Numerous fixes for register allocation bugs, preventing data corruption when spilling and reloading registers (#26411, #26526, #26537, #26542, #26550) * Fixes for several compiler crashes, including issues with CSE (#25468), and the simplifier(#26681), implicit parameters (#26451), and the type-class specialiser (#26682) * Fixed cast worker/wrapper incorrectly firing on INLINE functions (#26903) * Fixed LLVM backend miscompilation of bit manipulation operations (#20645, #26065, #26109) * Fixed associated type family and data family instance changes not triggering recompilation (#26183, #26705) * Fixed negative type literals causing the compiler to hang (#26861) * Improvements to determinism of compiler output (#26846, #26858) * Fixes for eventlog shutdown deadlocks (#26573) and lost wakeups in the RTS (#26324) * Fixed split sections support on Windows (#26696, #26494) and the LLVM backend (#26770) * Fixes for the bytecode compiler, PPC native code generator, and Wasm backend * The runtime linker now supports COMMON symbols (#6107) * Improved backtrace support: backtraces for `error` exceptions are now evaluated at throw time * `NamedDefaults` now correctly requires the class to be standard or have an in-scope default declaration, and handles poly-kinded classes (#25775, #25778, #25882) * ... and many more 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][]. 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) * [Mercury](https://mercury.com) We would like to thank 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/9.12.4-… [status]: https://gitlab.haskell.org/ghc/ghc/-/wikis/GHC-status [downloads.haskell.org] https://downloads.haskell.org/ghc/9.12.4 [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new

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Re: GHC 9.12.4-rc1 is now available
by Zubin Duggal 18 Mar '26

18 Mar '26

Can you clarify what behavior you are seeing? I just tested with fresh install ❯ test/bin/ghc --version The Glorious Glasgow Haskell Compilation System, version 9.12.3.20260311 ❯ test/bin/ghc $PROJECT_DIR/Main.hs -fforce-recomp [1 of 2] Compiling Main ( /home/zubin/ghcs/exprType/Main.hs, /home/zubin/ghcs/exprType/Main.o ) [2 of 2] Linking /home/zubin/ghcs/exprType/Main [Objects changed] ❯ cat $PROJECT_DIR/Main.hs {-# OPTIONS_GHC -O #-} import Data.Word prop :: Word8 -> IO () prop x = do print (x, x `quot` 7, x `rem` 7, x `quotRem` 7) {-# NOINLINE prop #-} main :: IO () main = prop 0 ❯ /home/zubin/ghcs/exprType/Main (0,0,0,(0,0)) On 26/03/18 11:01, George Colpitts wrote: >Hello > >Below it states > > - Fixed a critical code generation regression where sub-word division > produced incorrect results (#26711 </ghc/ghc/-/issues/26711>, #26668 > (closed) </ghc/ghc/-/issues/26668>), similar to the bug fixed in 9.12.2 > >However when I test 26711 it on 9.12.3.20260311 ( 9.12.3.20260311) on my >Apple Silicon Mac it is still broken, I've updated 26711. Maybe the above >means that just 26668 is fixed but 26711 is not? > >On Fri, Mar 13, 2026 at 6:15 AM Zubin Duggal via ghc-devs < >ghc-devs(a)haskell.org> wrote: > >> The GHC developers are very pleased to announce the availability >> of the release candidate for GHC 9.12.4. Binary distributions, source >> distributions, and documentation are available at [downloads.haskell.org][] >> and >> via [GHCup](https://www.haskell.org/ghcup/). >> >> GHC 9.12.4 is a bug-fix release fixing many issues of a variety of >> severities and scopes, including: >> >> * Fixed a critical code generation regression where sub-word division >> produced >> incorrect results (#26711, #26668), similar to the bug fixed in 9.12.2 >> * Numerous fixes for register allocation bugs, preventing data corruption >> when spilling and reloading registers >> (#26411, #26526, #26537, #26542, #26550) >> * Fixes for several compiler crashes, including issues with >> CSE (#25468), SetLevels (#26681), >> implicit parameters (#26451), and the type-class specialiser (#26682) >> * Fixed cast worker/wrapper incorrectly firing on INLINE functions (#26903) >> * Fixed LLVM backend miscompilation of bit manipulation operations >> (#20645, #26065, #26109) >> * Fixed associated type family and data family instance changes not >> triggering >> recompilation (#26183, #26705) >> * Fixed negative type literals causing the compiler to hang (#26861) >> * Improvements to determinism of compiler output (#26846, #26858) >> * Fixes for eventlog shutdown deadlocks (#26573) >> and lost wakeups in the RTS (#26324) >> * Fixed split sections support on Windows (#26696, #26494) and the LLVM >> backend (#26770) >> * Fixes for the bytecode compiler, PPC native code generator, and Wasm >> backend >> * The runtime linker now supports COMMON symbols (#6107) >> * Improved backtrace support: backtraces for `error` exceptions are now >> evaluated at throw time >> * `NamedDefaults` now correctly requires the class to be standard or have >> an >> in-scope default declaration, and handles poly-kinded classes (#25775, >> #25778, #25882) >> * ... and many more >> >> 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 26 March 2026. >> >> 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) >> * [Mercury](https://mercury.com) >> >> We would like to thank 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/9.12.4-… >> [status]: https://gitlab.haskell.org/ghc/ghc/-/wikis/GHC-status >> [downloads.haskell.org] https://downloads.haskell.org/ghc/9.12.4-rc1 >> [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new >> _______________________________________________ >> ghc-devs mailing list -- ghc-devs(a)haskell.org >> To unsubscribe send an email to ghc-devs-leave(a)haskell.org >>

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GHC 9.12.4-rc1 is now available
by Zubin Duggal 13 Mar '26

13 Mar '26

The GHC developers are very pleased to announce the availability of the release candidate for GHC 9.12.4. Binary distributions, source distributions, and documentation are available at [downloads.haskell.org][] and via [GHCup](https://www.haskell.org/ghcup/). GHC 9.12.4 is a bug-fix release fixing many issues of a variety of severities and scopes, including: * Fixed a critical code generation regression where sub-word division produced incorrect results (#26711, #26668), similar to the bug fixed in 9.12.2 * Numerous fixes for register allocation bugs, preventing data corruption when spilling and reloading registers (#26411, #26526, #26537, #26542, #26550) * Fixes for several compiler crashes, including issues with CSE (#25468), SetLevels (#26681), implicit parameters (#26451), and the type-class specialiser (#26682) * Fixed cast worker/wrapper incorrectly firing on INLINE functions (#26903) * Fixed LLVM backend miscompilation of bit manipulation operations (#20645, #26065, #26109) * Fixed associated type family and data family instance changes not triggering recompilation (#26183, #26705) * Fixed negative type literals causing the compiler to hang (#26861) * Improvements to determinism of compiler output (#26846, #26858) * Fixes for eventlog shutdown deadlocks (#26573) and lost wakeups in the RTS (#26324) * Fixed split sections support on Windows (#26696, #26494) and the LLVM backend (#26770) * Fixes for the bytecode compiler, PPC native code generator, and Wasm backend * The runtime linker now supports COMMON symbols (#6107) * Improved backtrace support: backtraces for `error` exceptions are now evaluated at throw time * `NamedDefaults` now correctly requires the class to be standard or have an in-scope default declaration, and handles poly-kinded classes (#25775, #25778, #25882) * ... and many more 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 26 March 2026. 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) * [Mercury](https://mercury.com) We would like to thank 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/9.12.4-… [status]: https://gitlab.haskell.org/ghc/ghc/-/wikis/GHC-status [downloads.haskell.org] https://downloads.haskell.org/ghc/9.12.4-rc1 [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new

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Upcoming ghc-10.0 fork
by Andreas Klebinger 09 Mar '26

09 Mar '26

Hello everyone, time marches and so do our plans for future releases. We plan to fork the 10.0 branch early on in April (likely the 1st). If you have work you want to see land in 10.0 please try to land it on ghc-master before that time, as we plan to do no *feature* backports beyond that point. Bugfixes of course will continue to be backported beyond the fork date. If you are maintaining a boot library and you expect any issues or want to make a new release specificly for the release please let us know. Ideally on the release tracking ticket: https://gitlab.haskell.org/ghc/ghc/-/issues/26992 Unless we hear otherwise we plan to bump all boot libraries to their latest published version over the next few weeks and we will let you know if we run into any issues while doing so. Cheers Andreas

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Critical code generation bug with GHC 9.12.3
by Zubin Duggal 08 Jan '26

08 Jan '26

Hello all, Unfortunately we discovered a major code generation regression in GHC 9.12.3 that results in incorrect runtime results for certain operations involving sub-word divisions. We recommend avoiding upgrading to this minor release at this time. See https://gitlab.haskell.org/ghc/ghc/-/issues/26711 for more details. This is the same bug that affected GHC 9.12.1. A patch re-introducing this bug was accidently backported onto the 9.12.3 branch and went unnoticed throughout the testing period. We are taking steps to ensure similar situations are less likely to occur again, including looking at ways to improve our testing procedure for minor GHC release, potentially using the Stackage infrastructure to run the testsuites of a broad range of packages to detect such issues. We are also starting to prepare GHC 9.12.4 with a fix, which we hope to release soon. However, a significant amount of time has passed since the initial set of backports to GHC 9.12.3 were completed, which means that a number of merge requests addressing issues of various severities has been marked for backporting to the GHC 9.12 branch. We are in the process of triaging this list and preparing a robust and reliable GHC 9.12.4 release. Thanks, Zubin.

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GHC 9.12.3 is now available
by Zubin Duggal 27 Dec '25

27 Dec '25

The GHC developers are very pleased to announce the release of GHC 9.12.3. Binary distributions, source distributions, and documentation are available at [downloads.haskell.org][]. GHC 9.12.3 is a bug-fix release fixing many issues of a variety of severities and scopes, including: * Fix a number of crashes and miscompilations in the compiler frontend (#25004, #25960, #26256) * Improvements to efficiency of the runtime linker (#26009) * Fixes for several bugs in bytecode generation and the bytecode interpreter (#23210, #25975, #25750) * Fixes for bugs in the handling of WHITEHOLEs in the RTS (#26204, #26205) * Fix incorrect code generation for SSE vector operations (#25859) * Fix a use-after-free in the Windows runtime linker (#26613) * Support for synchronous JSFFI exports for the wasm backend * And many more! 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][]. 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) * [Mercury](https://mercury.com) We would like to thank 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://downloads.haskell.org/~ghc/9.12.3/docs/users_guide/9.12.3-notes.html [status]: https://gitlab.haskell.org/ghc/ghc/-/wikis/GHC-status [downloads.haskell.org] https://downloads.haskell.org/ghc/9.12.3 [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new

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GHC 9.14.1 is now available
by Zubin Duggal 19 Dec '25

19 Dec '25

The GHC developers are very pleased to announce the release of GHC 9.14.1. Binary distributions, source distributions, and documentation are available at [downloads.haskell.org][]. GHC 9.14 brings 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 * Greatly improved [SSE/AVX2 support][sse] in the x86 native code generator backend * Initial native code generator support for LoongArch * The WebAssembly backend now supports [evaluation via the interpreter][wasm-ghci], allowing GHCi and TemplateHaskell evaluation, including `foreign import javascript` usage from within the browser * A new primop [`annotateStack#`][annotate-stack] for pushing arbitrary data onto the call stack for later extraction when decoding stack traces * [`-Wincomplete-record-selectors`][incomplete-selectors] is now part of `-Wall`. Libraries compiled with `-Werror` may need adjustment. * A major update of the Windows toolchain * Improved compatibility with [macOS Tahoe][macos] * ... and many more A full accounting of changes can be found in the [release notes][]. See the [migration guide][] for guidance on migrating programs to this release. Note that while this release makes many improvements in the specialisation optimisation, polymorphic specialisation remains disabled by default in the 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. 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 thank 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 comprises this release. 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 [release notes]: https://downloads.haskell.org/ghc/9.14.1/docs/users_guide/9.14.1-notes.html [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… [wasm-ghci]: https://www.tweag.io/blog/2025-04-17-wasm-ghci-browser/ [incomplete-selectors]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0516-i… [annotate-stack]: https://gitlab.haskell.org/ghc/ghc/-/issues/26218 [migration guide]: https://gitlab.haskell.org/ghc/ghc/-/wikis/migration/9.14 [sse]: https://gitlab.haskell.org/ghc/ghc/-/issues/25030

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GHC 9.12.3-rc3 is now available
by Zubin Duggal 11 Dec '25

11 Dec '25

The GHC developers are very pleased to announce the availability of the third 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 22 December 2025. The changes from the first release candidate are - Fix use after free on windows due to a linker optimisation introduced in an earlier RC (#26613) - A fix for a bug in the configure script which result in the LLVM toolchain not being detected in certain situations (#26564) - Fixes for the WASM backend 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-rc3 [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new

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GHC 9.14.1-rc3 is now available
by Zubin Duggal 02 Dec '25

02 Dec '25

The previous email had an incorrect subject line, GHC 9.14.1-rc3 is what it was intended to say. The contents following this are the same. The GHC developers are very pleased to announce the availability of the third release candidate of GHC 9.14.1. Binary distributions, source distributions, and documentation are available at [downloads.haskell.org][]. The changes from the second release candidate are: - Fix RTS segfaults in certain situations (#26495) - Fix use after free on windows due to a linker optimisation introduced in an earlier RC (#26613) 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. 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. [downloads.haskell.org] https://downloads.haskell.org/ghc/9.14.1-rc3 [release notes]: https://downloads.haskell.org/ghc/9.14.1-rc3/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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