GHC 9.12.3-rc2 is now available
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-notes.rst?ref_type=heads&plain=1 [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
Thanks Zubin. I found a small problem; hopefully it is unique to me:
% ghc --version
The Glorious Glasgow Haskell Compilation System, version 9.12.2.20251110
% ghc -O2 -fllvm prob214ff.hs
Loaded package environment from
/Users/gcolpitts/.ghc/aarch64-darwin-9.12.2.20251110/environments/default
[1 of 2] Compiling Main ( prob214ff.hs, prob214ff.o ) [Missing
object file]
<no location info>: warning: [GHC-66599]
GHC was not configured with a supported LLVM toolchain
Make sure you have installed LLVM between [13 and 20) and reinstall GHC
to ensure -fllvm works
<no location info>: error:
Warning: Couldn't figure out LLVM version!
Make sure you have installed LLVM between [13 and 20)
Failed to detect LLVM version!
Make sure LLVM is installed correctly.
We will try though...
<no location info>: error: LLVM Optimiser: could not execute:
Although llvm 21 is not supported my understanding is that it is supposed
to try as it says above. I do have llvm installed:
opt --version
Homebrew LLVM version 21.1.5
Optimized build.
Default target: arm64-apple-darwin25.1.0
Host CPU: apple-m4
(base) gcolpitts@Mac haskell %
Plus configure also thinks I have it installed:
checking for llc... llc
checking llc version (21.1.5) is between 13 and 20... no
configure: We only support llvm 13 upto 20 (non-inclusive) *(found 21.1.5).*
checking for opt-19... no
checking for opt-19.0... no
checking for opt19... no
checking for opt-18... no
checking for opt-18.0... no
checking for opt18... no
checking for opt-17... no
checking for opt-17.0... no
checking for opt17... no
checking for opt-16... no
checking for opt-16.0... no
checking for opt16... no
checking for opt-15... no
checking for opt-15.0... no
checking for opt15... no
checking for opt-14... no
checking for opt-14.0... no
checking for opt14... no
checking for opt-13... no
checking for opt-13.0... no
checking for opt13... no
checking for opt... opt
checking opt version (21.1.5) is between 13 and 20... no
configure: We only support llvm 13 upto 20 (non-inclusive)
checking for llc... llc
checking llc version (21.1.5) is between 13 and 20... no
configure: We only support llvm 13 upto 20 (non-inclusive) *(found 21.1.5).*
checking for opt-19... no
checking for opt-19.0... no
checking for opt19... no
checking for opt-18... no
checking for opt-18.0... no
checking for opt18... no
checking for opt-17... no
checking for opt-17.0... no
checking for opt17... no
checking for opt-16... no
checking for opt-16.0... no
checking for opt16... no
checking for opt-15... no
checking for opt-15.0... no
checking for opt15... no
checking for opt-14... no
checking for opt-14.0... no
checking for opt14... no
checking for opt-13... no
checking for opt-13.0... no
checking for opt13... no
checking for opt... opt
checking opt version (21.1.5) is between 13 and 20... no
configure: We only support llvm 13 upto 20 (non-inclusive) *(found 21.1.5).*
Suggestions?
Thanks
George
On Tue, Nov 11, 2025 at 4:02 AM Zubin Duggal
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-notes.rst?ref_type=heads&plain=1 [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 _______________________________________________ ghc-devs mailing list -- ghc-devs@haskell.org To unsubscribe send an email to ghc-devs-leave@haskell.org
Can you open a ticket for this please? On 25/11/11 14:17, George Colpitts wrote:
Thanks Zubin. I found a small problem; hopefully it is unique to me:
% ghc --version The Glorious Glasgow Haskell Compilation System, version 9.12.2.20251110
% ghc -O2 -fllvm prob214ff.hs Loaded package environment from /Users/gcolpitts/.ghc/aarch64-darwin-9.12.2.20251110/environments/default [1 of 2] Compiling Main ( prob214ff.hs, prob214ff.o ) [Missing object file] <no location info>: warning: [GHC-66599] GHC was not configured with a supported LLVM toolchain Make sure you have installed LLVM between [13 and 20) and reinstall GHC to ensure -fllvm works
<no location info>: error: Warning: Couldn't figure out LLVM version! Make sure you have installed LLVM between [13 and 20)
Failed to detect LLVM version! Make sure LLVM is installed correctly. We will try though... <no location info>: error: LLVM Optimiser: could not execute:
Although llvm 21 is not supported my understanding is that it is supposed to try as it says above. I do have llvm installed:
opt --version Homebrew LLVM version 21.1.5 Optimized build. Default target: arm64-apple-darwin25.1.0 Host CPU: apple-m4 (base) gcolpitts@Mac haskell %
Plus configure also thinks I have it installed:
checking for llc... llc checking llc version (21.1.5) is between 13 and 20... no configure: We only support llvm 13 upto 20 (non-inclusive) *(found 21.1.5).* checking for opt-19... no checking for opt-19.0... no checking for opt19... no checking for opt-18... no checking for opt-18.0... no checking for opt18... no checking for opt-17... no checking for opt-17.0... no checking for opt17... no checking for opt-16... no checking for opt-16.0... no checking for opt16... no checking for opt-15... no checking for opt-15.0... no checking for opt15... no checking for opt-14... no checking for opt-14.0... no checking for opt14... no checking for opt-13... no checking for opt-13.0... no checking for opt13... no checking for opt... opt checking opt version (21.1.5) is between 13 and 20... no configure: We only support llvm 13 upto 20 (non-inclusive) checking for llc... llc checking llc version (21.1.5) is between 13 and 20... no configure: We only support llvm 13 upto 20 (non-inclusive) *(found 21.1.5).* checking for opt-19... no checking for opt-19.0... no checking for opt19... no checking for opt-18... no checking for opt-18.0... no checking for opt18... no checking for opt-17... no checking for opt-17.0... no checking for opt17... no checking for opt-16... no checking for opt-16.0... no checking for opt16... no checking for opt-15... no checking for opt-15.0... no checking for opt15... no checking for opt-14... no checking for opt-14.0... no checking for opt14... no checking for opt-13... no checking for opt-13.0... no checking for opt13... no checking for opt... opt checking opt version (21.1.5) is between 13 and 20... no configure: We only support llvm 13 upto 20 (non-inclusive) *(found 21.1.5).*
Suggestions?
Thanks George
On Tue, Nov 11, 2025 at 4:02 AM Zubin Duggal
wrote: 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-notes.rst?ref_type=heads&plain=1 [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 _______________________________________________ ghc-devs mailing list -- ghc-devs@haskell.org To unsubscribe send an email to ghc-devs-leave@haskell.org
1. #26564 https://gitlab.haskell.org/ghc/ghc/-/issues/26564
On Wed, Nov 12, 2025 at 2:54 AM Zubin Duggal
Can you open a ticket for this please?
Thanks Zubin. I found a small problem; hopefully it is unique to me:
% ghc --version The Glorious Glasgow Haskell Compilation System, version 9.12.2.20251110
% ghc -O2 -fllvm prob214ff.hs Loaded package environment from /Users/gcolpitts/.ghc/aarch64-darwin-9.12.2.20251110/environments/default [1 of 2] Compiling Main ( prob214ff.hs, prob214ff.o ) [Missing object file] <no location info>: warning: [GHC-66599] GHC was not configured with a supported LLVM toolchain Make sure you have installed LLVM between [13 and 20) and reinstall GHC to ensure -fllvm works
<no location info>: error: Warning: Couldn't figure out LLVM version! Make sure you have installed LLVM between [13 and 20)
Failed to detect LLVM version! Make sure LLVM is installed correctly. We will try though... <no location info>: error: LLVM Optimiser: could not execute:
Although llvm 21 is not supported my understanding is that it is supposed to try as it says above. I do have llvm installed:
opt --version Homebrew LLVM version 21.1.5 Optimized build. Default target: arm64-apple-darwin25.1.0 Host CPU: apple-m4 (base) gcolpitts@Mac haskell %
Plus configure also thinks I have it installed:
checking for llc... llc checking llc version (21.1.5) is between 13 and 20... no configure: We only support llvm 13 upto 20 (non-inclusive) *(found 21.1.5).* checking for opt-19... no checking for opt-19.0... no checking for opt19... no checking for opt-18... no checking for opt-18.0... no checking for opt18... no checking for opt-17... no checking for opt-17.0... no checking for opt17... no checking for opt-16... no checking for opt-16.0... no checking for opt16... no checking for opt-15... no checking for opt-15.0... no checking for opt15... no checking for opt-14... no checking for opt-14.0... no checking for opt14... no checking for opt-13... no checking for opt-13.0... no checking for opt13... no checking for opt... opt checking opt version (21.1.5) is between 13 and 20... no configure: We only support llvm 13 upto 20 (non-inclusive) checking for llc... llc checking llc version (21.1.5) is between 13 and 20... no configure: We only support llvm 13 upto 20 (non-inclusive) *(found 21.1.5).* checking for opt-19... no checking for opt-19.0... no checking for opt19... no checking for opt-18... no checking for opt-18.0... no checking for opt18... no checking for opt-17... no checking for opt-17.0... no checking for opt17... no checking for opt-16... no checking for opt-16.0... no checking for opt16... no checking for opt-15... no checking for opt-15.0... no checking for opt15... no checking for opt-14... no checking for opt-14.0... no checking for opt14... no checking for opt-13... no checking for opt-13.0... no checking for opt13... no checking for opt... opt checking opt version (21.1.5) is between 13 and 20... no configure: We only support llvm 13 upto 20 (non-inclusive) *(found 21.1.5).*
Suggestions?
Thanks George
On Tue, Nov 11, 2025 at 4:02 AM Zubin Duggal
wrote: 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
On 25/11/11 14:17, George Colpitts wrote: 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]:
[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 _______________________________________________ ghc-devs mailing list -- ghc-devs@haskell.org To unsubscribe send an email to ghc-devs-leave@haskell.org
Somehow when I created the bug I deleted
/label ~bug
/label ~"needs triage"
Editing and adding them doesn't work. Can someone fix this?
Thanks
George
On Wed, Nov 12, 2025 at 10:35 AM George Colpitts
1. #26564 https://gitlab.haskell.org/ghc/ghc/-/issues/26564
On Wed, Nov 12, 2025 at 2:54 AM Zubin Duggal
wrote: Can you open a ticket for this please?
On 25/11/11 14:17, George Colpitts wrote:
Thanks Zubin. I found a small problem; hopefully it is unique to me:
% ghc --version The Glorious Glasgow Haskell Compilation System, version 9.12.2.20251110
% ghc -O2 -fllvm prob214ff.hs Loaded package environment from /Users/gcolpitts/.ghc/aarch64-darwin-9.12.2.20251110/environments/default [1 of 2] Compiling Main ( prob214ff.hs, prob214ff.o ) [Missing object file] <no location info>: warning: [GHC-66599] GHC was not configured with a supported LLVM toolchain Make sure you have installed LLVM between [13 and 20) and reinstall GHC to ensure -fllvm works
<no location info>: error: Warning: Couldn't figure out LLVM version! Make sure you have installed LLVM between [13 and 20)
Failed to detect LLVM version! Make sure LLVM is installed correctly. We will try though... <no location info>: error: LLVM Optimiser: could not execute:
Although llvm 21 is not supported my understanding is that it is supposed to try as it says above. I do have llvm installed:
opt --version Homebrew LLVM version 21.1.5 Optimized build. Default target: arm64-apple-darwin25.1.0 Host CPU: apple-m4 (base) gcolpitts@Mac haskell %
Plus configure also thinks I have it installed:
checking for llc... llc checking llc version (21.1.5) is between 13 and 20... no configure: We only support llvm 13 upto 20 (non-inclusive) *(found 21.1.5).* checking for opt-19... no checking for opt-19.0... no checking for opt19... no checking for opt-18... no checking for opt-18.0... no checking for opt18... no checking for opt-17... no checking for opt-17.0... no checking for opt17... no checking for opt-16... no checking for opt-16.0... no checking for opt16... no checking for opt-15... no checking for opt-15.0... no checking for opt15... no checking for opt-14... no checking for opt-14.0... no checking for opt14... no checking for opt-13... no checking for opt-13.0... no checking for opt13... no checking for opt... opt checking opt version (21.1.5) is between 13 and 20... no configure: We only support llvm 13 upto 20 (non-inclusive) checking for llc... llc checking llc version (21.1.5) is between 13 and 20... no configure: We only support llvm 13 upto 20 (non-inclusive) *(found 21.1.5).* checking for opt-19... no checking for opt-19.0... no checking for opt19... no checking for opt-18... no checking for opt-18.0... no checking for opt18... no checking for opt-17... no checking for opt-17.0... no checking for opt17... no checking for opt-16... no checking for opt-16.0... no checking for opt16... no checking for opt-15... no checking for opt-15.0... no checking for opt15... no checking for opt-14... no checking for opt-14.0... no checking for opt14... no checking for opt-13... no checking for opt-13.0... no checking for opt13... no checking for opt... opt checking opt version (21.1.5) is between 13 and 20... no configure: We only support llvm 13 upto 20 (non-inclusive) *(found 21.1.5).*
Suggestions?
Thanks George
On Tue, Nov 11, 2025 at 4:02 AM Zubin Duggal
wrote: 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]:
[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 _______________________________________________ ghc-devs mailing list -- ghc-devs@haskell.org To unsubscribe send an email to ghc-devs-leave@haskell.org
participants (2)
-
George Colpitts -
Zubin Duggal