- Glasgow-haskell-users

GHC 9.8.3 plans
by Ben Gamari 30 Sep '24

30 Sep '24

Hi all, I am currently in the process of preparing our next release in the 9.8 series, 9.8.3. This release will include well over 70 backports. As I am a bit less than half-way through the backport process I have currently scheduled the release date for Wednesday 16 October 2024. I have included a list of currently-planned backports below (however it is possible that some of those in the to-do section may be dropped due to feasibility). If you know of anything else which you suspect should be backported do let me know on this thread and by applying the usual ~"backport needed:9.8" label. Cheers, - Ben # Already backported * [x] !12748: rts: fix checkClosure error message * [x] !12734: Various rts fixes for issues spotted by UndefinedBehaviorSanitizer * [x] !13252: Bump submodule array to 0.5.8.0 * [x] !13240: Bump submodule deepseq to 1.5.1.0 * [x] !13306: ci: Fix variable inheritence for ghcup-metadata testing job * [x] !13276: Fix interaction between fork and kqueue (#24672) * [x] !13151: JS: support rubbish static literals (#25177) * [x] !13113: AARCH64 linker: skip NONE relocations * [x] !13096: Cmm: don't perform unsound optimizations on 32-bit compiler hosts (#24893 #24700) * [x] !13091: GHCi debugger: drop record name spaces for Ids * [x] !13070: Only lookup ghcversion.h file in the RTS include-dirs by default. * [x] !13038: Address #25055, by disabling case-of-runRW# in Gentle phase * [x] !13010: Linker: Add windows R_X86_64_PC64 relocation support * [x] !12990: Fix -freg-graphs for FP and AARch64 NCG (#24941). * [x] !12885: PPC NCG: Fix sign hints in C calls * [x] !12975: X86 NCG: Fix argument promotion in foreign C calls * [x] !12914: Linker: use m32 allocator for sections when NEED_PLT (#24432) * [x] !12784: compiler: emit NaturallyAligned when element type & index type are the same width * [x] !12773: GHCi interpreter: Tag constructor closures when possible. * [x] !12713: user_guide: Fix typo in MultiWayIf chapter * [x] !12665: Add missing parenthesizePat in cvtp * [x] !12655: Reverse arguments to stgCallocBytes (fix #24828) * [x] !12574: doc: Fix type error in hs_try_putmvar example * [x] !12558: Add test cases for #24664 * [x] !12484: compiler: Fingerprint -fwrite-if-simplified-core * [x] !12463: JS: correctly handle RUBBISH literals (#24664) * [x] !12459: Don't depend on registerPackage function in Cabal * [x] !12432: Fix ghc API link in docs/index.html # To-do * [ ] !13237: Add `IsBootInterface` to finder cache keys * [ ] !12756: WIP: GHC.Cmm.Opt: Fix overflow on 32bit hosts (error) * [ ] !12639: Bump os-string submodule to 2.0.2.2 * [ ] !12607: refactor quadratic search in warnMissingHomeModules * [ ] !12603: Compatibility with 9.8.1 as boot compiler (error) * [ ] !12548: driver: always merge objects when possible * [ ] !12514: Track in-scope variables in ruleCheckProgram * [ ] !12500: GHCi: support cross-module inlining of breakpoints (#24712) * [ ] !12416: Don't generate wrappers for `type data` constructors with StrictData * [ ] !12370: NCG: Fix a bug where we errounously removed a required jump instruction. * [ ] !12344: Fix off by one error in seekBinNoExpand and seekBin * [ ] !12328: Improve the duplicate-tyvar check * [ ] !12321: Fix type of _get_osfhandle foreign import * [ ] !12313: driver: force merge objects when building dynamic objects * [ ] !12308: JS: fix for h$appendToHsString (#24495) * [ ] !12299: libffi-tarballs: bump libffi-tarballs submodule to libffi 3.4.6 * [ ] !12282: configure: Use LDFLAGS when trying linkers * [ ] !12264: rts: Lookup symbols in relevant DLLs only (originally !11164) * [ ] !12256: NCG: Fix a bug in jump shortcutting. * [ ] !12227: rts: fix clang compilation on aarch64 * [ ] !12184: Use "module" instead of "library" when applicable in base haddocks * [ ] !12177: Update correct counter in bumpTickyAllocd * [ ] !12162: driver: Make `checkHomeUnitsClosed` faster * [ ] !12161: Fix haddock source links and hyperlinked source * [ ] !12158: x86-ncg: Fix fma codegen when arguments are globals. * [ ] !12146: rts: avoid checking bdescr of value outside of Haskell heap * [ ] !12122: Improve base library synopsis and description * [ ] !12116: rel-eng/fetch-gitlab.py: Fix name of aarch64 alpine 3_18 release job * [ ] !12042: rts: only collect live words in nonmoving census when non-concurrent * [ ] !12016: Enhance documentation of Data.Complex * [ ] !12011: Add @since annotation to Data.Data.mkConstrTag * [ ] !11989: Fix ffi callbacks with >6 args and non-64bit args. * [ ] !11938: Escape multiple arguments in the settings file * [ ] !11575: configure: Do not override existing linker flags in FP_LD_NO_FIXUP_CHAINS * [ ] !11548: Update the unification count in wrapUnifierX * [ ] !11541: Compability with 9.8.1 as boot compiler (error) * [ ] !11384: hadrian: Move hsc2hs wrapper generation to bindist installation * [ ] !11383: testsuite: Run some tests unconditionally in nonmoving ways (error) * [ ] !11285: Draft: hadrian: Update bootstrap plans (error) * [ ] !11181: Bump Haddock to fix #23616 [GHC 9.8 branch] (error) * [ ] !10995: Fix (~) and (@) infix operators in TH splices (#23748) * [ ] !10890: nonmoving: Add support for heap profiling * [ ] !10659: nonmoving: introduce a family of dense allocators * [ ] !10523: Add missing BCO handling in scavenge_one (#23375) * [ ] !10417: StgToByteCode: Don't assume that data con workers are nullary (error) * [ ] !9762: nativeGen/AArch64: Fix graph-colouring register allocator

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[ANNOUNCE] GHC 9.6.6 is now available
by Zubin Duggal 01 Jul '24

01 Jul '24

The GHC developers are happy to announce the availability of GHC 9.6.6. Binary distributions, source distributions, and documentation are available on the [release page](https://www.haskell.org/ghc/download_ghc_9_6_6.html). Blog Post: https://www.haskell.org/ghc/blog/20240701-ghc-9.6.6-released.html This release is primarily a bugfix release addressing some issues found in the 9.6 series. These include: * A fix for a bug in the NCG that could lead to incorrect runtime results due to erroneously removing a jump instruction (#24507). * A fix for a linker error that manifested on certain platform/toolchain combinations, particularly darwin with a brew provisioned toolchain, arising due to a confusion in linker options between GHC and cabal (#22210). * A fix for a compiler panic in the simplifier due to incorrect eta expansion (#24718). * A fix for possible segfaults when using the bytecode interpreter due to incorrect constructor tagging (#24870). * And a few more fixes A full accounting of changes can be found in the [release notes]. As some of the fixed issues do affect correctness users are encouraged to upgrade promptly. We would like to thank Microsoft Azure, GitHub, IOG, the Zw3rk stake pool, Well-Typed, Tweag I/O, Serokell, Equinix, SimSpace, 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 comprise this release. As always, do give this release a try and open a [ticket][] if you see anything amiss. Happy Hacking! -Zubin [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new [release notes]: https://downloads.haskell.org/~ghc/9.6.6/docs/users_guide/9.6.6-notes.html

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Priorities for upcoming GHC releases
by Zubin Duggal 21 May '24

21 May '24

Hi all, We detail our plans for upcoming GHC releases in a new blog post: https://www.haskell.org/ghc/blog/20240521-ghc-release-priorities.html The summary is that we will prioritise work on the 9.10, 9.6 and master branches over work on the 9.8 branch for the coming few months due to time and resource constraints. This does not mean that we are dropping support for GHC 9.8, but that releases in this series might be made at a slower pace than usual. Cheers, Zubin.

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GHC 9.10.1 is now available
by Ben Gamari 11 May '24

11 May '24

The GHC developers are very pleased to announce the release of GHC 9.10.1. Binary distributions, source distributions, and documentation are available at [downloads.haskell.org] and shortly via [GHCup]. GHC 9.10 brings a number of new features and improvements, including: * The introduction of the `GHC2024` language edition, building upon `GHC2021` with the addition of a number of widely-used extensions. * Partial implementation of the [GHC Proposal #281], allowing visible quantification to be used in the types of terms. * [Extension] of LinearTypes to allow linear `let` and `where` bindings * The implementation of the [exception backtrace proposal], allowing the annotation of exceptions with backtraces, as well as other user-defined context * Further improvements in the info table provenance mechanism, reducing code size to allow IPE information to be enabled more widely * Javascript FFI support in the WebAssembly backend * Improvements in the fragmentation characteristics of the low-latency non-moving garbage collector. * ... and many more A full accounting of changes can be found in the [release notes]. As always, GHC's release status, including planned future releases, can be found on the [GHC Wiki]. We would like to thank GitHub, IOG, the Zw3rk stake pool, Well-Typed, Tweag I/O, Serokell, Equinix, 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 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/9.10.1/docs/users_guide/9.10.1-notes.html [GHC Wiki]: https://gitlab.haskell.org/ghc/ghc/-/wikis/GHC-status [exception backtrace]: https://github.com/ghc-proposals/ghc-proposals/pull/330 [GHC Proposal #281]: https://github.com/ghc-proposals/ghc-proposals/pull/281 [linear let]: https://github.com/ghc-proposals/ghc-proposals/pull/624 [downloads.haskell.org] https://downloads.haskell.org/ghc/9.10.1 [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new [GHCup]: https://www.haskell.org/ghcup/

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[ANNOUNCE] GHC 9.6.5 is now available
by Zubin Duggal 16 Apr '24

16 Apr '24

The GHC developers are happy to announce the availability of GHC 9.6.5. Binary distributions, source distributions, and documentation are available on the [release page](https://www.haskell.org/ghc/download_ghc_9_6_5.html). GHC Blog Post: https://www.haskell.org/ghc/blog/20240416-ghc-9.6.5-released.html This release is primarily a bugfix release addressing some issues found in the 9.6 series. These include: * Bumping the bundled `process` library to 1.6.19.0 to avoid a potential [command injection vulnerability] on Windows for clients of this library. This isn't known to affect GHC itself, but allows users who depend on the installed version of the `process` to avoid the issue. * Fixing a bug resulting in the distributed ``hsc2hs`` wrapper using flags from the compiler build environment (#24050). * Disabling the `-fasm-shortcutting` optimisation with `-O2` as it is known to result in unsoundess and incorrect runtime results in some cases (#24507). * Ensuring we take ``LDFLAGS`` into account when configuring a linker (#24565). * Fixing a bug arising from incorrect parsing of paths containing spaces in the settings file (#24265). * And many more fixes A full accounting of changes can be found in the [release notes]. As some of the fixed issues do affect correctness users are encouraged to upgrade promptly. We would like to thank Microsoft Azure, GitHub, IOG, the Zw3rk stake pool, Well-Typed, Tweag I/O, Serokell, Equinix, SimSpace, 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 comprise this release. As always, do give this release a try and open a [ticket][] if you see anything amiss. Enjoy! -Zubin [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new [release notes]: https://downloads.haskell.org/~ghc/9.6.5/docs/users_guide/9.6.5-notes.html [command injection vulnerability]: https://github.com/haskell/security-advisories/blob/main/advisories/hackage…

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[ANNOUNCE] GHC 9.10.1-alpha3 is now available
by Ben Gamari 15 Apr '24

15 Apr '24

The GHC developers are very pleased to announce the availability of the third alpha release of GHC 9.10.1. Binary distributions, source distributions, and documentation are available at https://downloads.haskell.org/ghc/9.10.1-alpha3 We hope to have this release available via ghcup shortly. GHC 9.10 will bring a number of new features and improvements, including: * The introduction of the `GHC2024` language edition, building upon `GHC2021` with the addition of a number of widely-used extensions. * Partial implementation of the [GHC Proposal #281], allowing visible quantification to be used in the types of terms. * [Extension] of LinearTypes to allow linear `let` and `where` bindings ([linear let]) * The implementation of the [exception backtrace proposal], allowing the annotation of exceptions with backtraces, as well as other user-defined context * Further improvements in the info table provenance mechanism, reducing code size to allow IPE information to be enabled more widely * Javascript FFI support in the WebAssembly backend * Improvements in the fragmentation characteristics of the low-latency non-moving garbage collector. * ... and many more A full accounting of changes 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 alpha is the penultimate prerelease leading to 9.10.1. In two weeks we plan to publish a release candidate, followed, if all things go well, by the final release a week later. We would like to thank GitHub, IOG, the Zw3rk stake pool, Well-Typed, Tweag I/O, Serokell, Equinix, 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 comprise this release. As always, do give this release a try and open a [ticket] if you see anything amiss. Cheers, ~ Ben [release notes]: https://downloads.haskell.org/ghc/9.10.1-alpha3/docs/users_guide/9.10.1-not… [status]: https://gitlab.haskell.org/ghc/ghc/-/wikis/GHC-status [exception backtrace]: https://github.com/ghc-proposals/ghc-proposals/pull/330 [GHC Proposal #281]: https://github.com/ghc-proposals/ghc-proposals/pull/281 [linear let]: https://github.com/ghc-proposals/ghc-proposals/pull/624 [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new

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[ANNOUNCE] GHC 9.10.1-alpha2 is now available
by Ben Gamari 29 Mar '24

29 Mar '24

The GHC developers are very pleased to announce the availability of the second alpha release of GHC 9.10.1. Binary distributions, source distributions, and documentation are available at https://downloads.haskell.org/ghc/9.10.1-alpha2 We hope to have this release available via ghcup shortly. GHC 9.10 will bring a number of new features and improvements, including: * The introduction of the `GHC2024` language edition, building upon `GHC2021` with the addition of a number of widely-used extensions. * Partial implementation of the [GHC Proposal #281], allowing visible quantification to be used in the types of terms. * [Extension] of LinearTypes to allow linear `let` and `where` bindings ([linear let]) * The implementation of the [exception backtrace proposal], allowing the annotation of exceptions with backtraces, as well as other user-defined context * Further improvements in the info table provenance mechanism, reducing code size to allow IPE information to be enabled more widely * Javascript FFI support in the WebAssembly backend * Improvements in the fragmentation characteristics of the low-latency non-moving garbage collector. * ... and many more A full accounting of changes 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]. We would like to thank GitHub, IOG, the Zw3rk stake pool, Well-Typed, Tweag I/O, Serokell, Equinix, 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 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/9.10.1-alpha2/docs/users_guide/9.10.1-not… [status]: https://gitlab.haskell.org/ghc/ghc/-/wikis/GHC-status [exception backtrace]: https://github.com/ghc-proposals/ghc-proposals/pull/330 [GHC Proposal #281]: https://github.com/ghc-proposals/ghc-proposals/pull/281 [linear let]: https://github.com/ghc-proposals/ghc-proposals/pull/624 [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new

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[ANNOUNCE] GHC 9.10.1-alpha1 is now available
by Ben Gamari 13 Mar '24

13 Mar '24

The GHC developers are very pleased to announce the availability of the first alpha release of GHC 9.10.1. Binary distributions, source distributions, and documentation are available at https://downloads.haskell.org/ghc/9.10.1-alpha1 We hope to have this release available via ghcup shortly. GHC 9.10 will bring a number of new features and improvements, including: * The introduction of the GHC2024 language edition, building upon GHC2021 with the addition of a number of widely-used extensions. * Partial implementation of the [GHC Proposal #281], allowing visible quantification to be used in the types of terms. * Extension of LinearTypes to allow linear `let` and `where` bindings ([linear-let]) * The implementation of the exception backtrace proposal, allowing the annotation of exceptions with backtraces, as well as other user-defined context [exception backtrace] * Further improvements in the info table provenance mechanism, reducing code size to allow IPE information to be enabled more widely * Javascript FFI support in the WebAssembly backend * Improvements in the fragmentation characteristics of the low-latency non-moving garbage collector. * ... and many more A full accounting of changes 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]. Many will notice that this release comes a fair bit later than the previously-announced schedule. While this delay has been attributable to a variety factors, the most recent cause is a set of issues with GHC 9.10's binary distributions on Windows (#24542). Instead of continuing to hold up the release process while we sort out this situation, we have instead provided this alpha without the usual assortment of Windows binary distributions. We expect to have this resolved by alpha 2; apologies to eager Windows testers for this delay. We would like to thank GitHub, IOG, the Zw3rk stake pool, Well-Typed, Tweag I/O, Serokell, Equinix, 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 comprise this release. As always, do give this release a try and open a [ticket] if you see anything amiss. Happy compiling, ~ Ben [release notes]: https://downloads.haskell.org/ghc/9.10.1-alpha1/docs/users_guide/9.10.1-not… [status]: https://gitlab.haskell.org/ghc/ghc/-/wikis/GHC-status [exception backtrace]: https://github.com/ghc-proposals/ghc-proposals/pull/330 [GHC Proposal #281]: https://github.com/ghc-proposals/ghc-proposals/pull/281 [linear let]: https://github.com/ghc-proposals/ghc-proposals/pull/624

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[ANNOUNCE] GHC 9.8.2 is now available
by Zubin Duggal 23 Feb '24

23 Feb '24

The GHC developers are happy to announce the availability of GHC 9.8.2. Binary distributions, source distributions, and documentation are available on the [release page](https://www.haskell.org/ghc/download_ghc_9_8_2.html). GHC Blog Post: https://www.haskell.org/ghc/blog/20240223-ghc-9.8.2-released.html This release is primarily a bugfix release addressing many issues found in the 9.8 series. These include: * A fix for a bug where certain warnings flags were not recognised (#24071) * Fixes for bugs in the renamer and typechecker (#24084, #24134, #24279, #24083) * Fixes for bugs in the simplifier and code generator (#24160, #24242, #23628, #23659, #24160, #23862, #24295, #24370) * Fixes for some memory leaks in GHCi (#24107, #24118) * Improvements to error messages (#21097, #16996, #11050, #24196, #24275, #23768, #23784, #23778) * A fix for a recompilation checking bug where GHC may miss changes in transitive dependencies when deciding to relink a program (#23724). * And many more fixes A full accounting of changes can be found in the [release notes]. As some of the fixed issues do affect correctness users are encouraged to upgrade promptly. We would like to thank Microsoft Azure, GitHub, IOG, the Zw3rk stake pool, Well-Typed, Tweag I/O, Serokell, Equinix, SimSpace, 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 comprise this release. As always, do give this release a try and open a [ticket][] if you see anything amiss. Enjoy! -Zubin [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new [release notes]: https://downloads.haskell.org/~ghc/9.8.2/docs/users_guide/9.8.2-notes.html

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How to build executables that will dump live backtraces
by Clinton Mead 21 Feb '24

21 Feb '24

Hi All I've noticed this is a quiet mailing list recently, but I couldn't find a more appropriate place to ask this question. Please say if there's somewhere else I should be asking. It's my understanding that one can get GHC executables to dump backtraces of all their running threads to stderr upon receiving SIGQUIT. And the way to do that is to build with 'libdw' support. We have a build system using Nix, and we're unfortunately a bit behind on GHC 9.2.2 atm, but in anycase, I noticed in a Nix develop shell when I run `ghc --info | grep libdw` I get: ,("RTS expects libdw","NO") So I instead added the following to my Haskell package overrides: ghc = old.ghc.overrideAttrs (oldAttrs: { configureFlags = oldAttrs.configureFlags ++ [ "--with-libdw-includes=${pkgs.elfutils.dev}/include" "--with-libdw-libraries=${pkgs.elfutils.out}/lib" "--enable-dwarf-unwind" ]; buildInputs = oldAttrs.buildInputs ++ [pkgs.elfutils]; }); I basically copy/pastaed this from https://github.com/input-output-hk/haskell.nix/blob/master/compiler/ghc/def… And this seems to work, now when I run `ghc --info` I get: ,("RTS expects libdw","YES") But despite building with this version of GHC, still when I send `SIGQUIT` to a process built with this version of GHC, I just get the message: "This build does not support backtraces." Now I have also been building my packages with `-g`, passing `--enable-debug-info` etc, although it's my understanding that what I've done just with building GHC with `--enable-dwarf-unwind` _should_ be enough to get a backtrace upon SIGQUIT, it might just be a poor one if the debugging symbols aren't added. But clearly I've missed something if it's not working. I'm not quite sure what set of circumstances the message "This build does not support backtraces" is displayed? Is there a runtime check to see whether the "libdw" library is actually in the library path, in addition to the requirement that GHC be built with libdw support? If that's the case, perhaps as I'm running this on NixOS I need to add something to my executable's LD_LIBRARY_PATH or something? Or is there some option I need to give GHC/Cabal to ensure that backtrace support is added to the executable's runtime as well as making sure I've compiled with GHC that's compiled with libdw support? Or is there some other runtime RTS option I need to give to my executable? As you can see, I'm completely lost about how to move forward on this, so any help would be very much appreciated. Thanks, Clinton

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