- ghc-devs - Haskell.org

questions about head.hackage
by jappie klooster 24 Jul '24

24 Jul '24

Hello everyone, For the stability working group I'm trying to understand how many packages head.hackage allows you to build. Does anyone know the answer to this or have an idea how I can find out? For context, the stability working group is a group of interested people who try and allow ghc and haskell system to innovate, while reducing the amount of friction caused to the wider Haskell community. Current efforts include the marking language proposals as stable, and my work of investigating historic breakage. Investigating this breakage will allow us to make better informed decisions on which pain points to prioritize. -- With regards, Jappie Klooster e: hi(a)jappie.me w: https://jappie.me m: +31644237437

4 4

Gitlab upgrade tomorrow
by Andreas Klebinger 19 Jul '24

19 Jul '24

Hi all, Gitlab will be temporarily unavailable tomorrow around 9:00 AM CEST while it's updated. This should not take long, but a short downtime is expected. Cheers, - Andreas

2 2

Cabal and GHC: the big picture
by Simon Peyton Jones 18 Jul '24

18 Jul '24

Friends You may remember a recent thread on ghc-devs about GHC and Cabal <https://mail.haskell.org/pipermail/ghc-devs/2024-July/021678.html>. In it I say how I feel I lack the "big picture" of how GHC and Cabal interact, and that my mental model is probably faulty. Tom Ellis took pity on me, and together we wrote this big-picture overview about how GHC and Cabal interact <https://docs.google.com/document/d/1mQEpV3fYz1pHi64KTnlv8gifh9ONQ-jytk5sIHq…>. Would you like to: - Read it as a consumer. - Does it tell you stuff that is useful? - What else would you like to know? - What is un-clear or missing? - Read it as an expert. - Is it accurate? - Are any bits misleading? - Do the links go to appropriate places? - What other links or resource would be helpful. It is not intended as a replacement for the GHC user guide, nor the Cabal user guide; rather it is littered with links to those guides which give much fuller details. Rather, it is intended to put you (well, me for one!) in a position where you can more easily make sense of those documents. We'd love to have your help in improving it. Simon

4 8

submodules update warning?
by Brandon Allbery 13 Jul '24

13 Jul '24

I got several of these while updating my local ghc checkout: ``` Fetching submodule libraries/binary remote: error: MIDX does not contain the BTMP chunk remote: warning: unable to load pack: 'pack-1d2d40f15dad726ad220801f9d5bd5b527bc7493.idx', disabling pack-reuse >From https://gitlab.haskell.org/ghc/packages/binary * [new branch] wip/edsko -> origin/wip/edsko ``` Is this something I need to worry about? -- brandon s allbery kf8nh allbery.b(a)gmail.com

1 0

CI stuck?
by Simon Peyton Jones 12 Jul '24

12 Jul '24

Dear GHC devs Is GHC's CI stuck in some way? My !12928 has been scheduled by Marge over 10 times now, and each time the commit has failed. Ten seems... a lot. Thanks Simon

2 1

The reason for non-GHC boot dependencies
by Hécate 11 Jul '24

11 Jul '24

Hi devs, I had a chat earlier today with someone and found myself unable to explain the reason why GHC came with boot dependencies like xhtml, that are dependencies of Haddock and HPC. Obviously, the binaries are (haskell-)dynamically linked when distributed, but what is the reason why haddock, hpc, etc can't be (haskell-)statically linked when distributed? Surely the size of binaries can't be the only concern, otherwise we'd use upx¹ on them when distributing them. Cheers, Hécate 1: https://upx.github.io -- Hécate ✨ 🐦: @TechnoEmpress IRC: Hecate WWW: https://glitchbra.in RUN: BSD

5 8

Cannot build `master`, tries to use GHC 9.2?!
by ÉRDI Gergő 11 Jul '24

11 Jul '24

Hi, I'm trying to build GHC 5b1aefb70edbd54ac899896df39d8f3d6c579518 but I'm running into a weird problem. Using `hadrian/build-stack`, it fails quite early on with: | Run Ghc CompileCWithGhc (Stage0 GlobalLibs): utils/hsc2hs/cbits/utils.c => _build/stageBoot/utils/hsc2hs/build/c/cbits/utils.o Command line: ghc -Wall -hisuf hi -osuf o -hcsuf hc -static -hide-all-packages -no-user-package-db '-package-env -' '-package-db _build/stageBoot/inplace/package.conf.d' '-this-unit-id hsc2hs-0.68.10-inplace' '-this-package-name hsc2hs' '-package-id base-4.16.4.0' '-package-id containers-0.6.5.1' '-package-id directory-1.3.6.2' '-package-id filepath-1.4.2.2' '-package-id process-1.6.16.0' -i -i/home/cactus/prog/haskell/ghc/ghc.master/_build/stageBoot/utils/hsc2hs/build -i/home/cactus/prog/haskell/ghc/ghc.master/_build/stageBoot/utils/hsc2hs/build/hsc2hs/autogen -i/home/cactus/prog/haskell/ghc/ghc.master/utils/hsc2hs/src/ -I_build/stageBoot/utils/hsc2hs/build -I/home/cactus/.ghcup/ghc/9.2.8/lib/ghc-9.2.8/process-1.6.16.0/include -I/home/cactus/.ghcup/ghc/9.2.8/lib/ghc-9.2.8/unix-2.7.2.2/include -I/home/cactus/.ghcup/ghc/9.2.8/lib/ghc-9.2.8/time-1.11.1.1/include -I/home/cactus/.ghcup/ghc/9.2.8/lib/ghc-9.2.8/bytestring-0.11.4.0/include -I/home/cactus/.ghcup/ghc/9.2.8/lib/ghc-9.2.8/base-4.16.4.0/include -I/home/cactus/.ghcup/ghc/9.2.8/lib/ghc-9.2.8/ghc-bignum-1.2/include -I/home/cactus/.ghcup/ghc/9.2.8/lib/ghc-9.2.8/include -optP-include -optP_build/stageBoot/utils/hsc2hs/build/hsc2hs/autogen/cabal_macros.h -optP-DIN_GHC_TREE -outputdir _build/stageBoot/utils/hsc2hs/build -fdiagnostics-color=always -Wall -XHaskell2010 -optc-I_build/stageBoot/utils/hsc2hs/build -optc-I/home/cactus/.ghcup/ghc/9.2.8/lib/ghc-9.2.8/process-1.6.16.0/include -optc-I/home/cactus/.ghcup/ghc/9.2.8/lib/ghc-9.2.8/unix-2.7.2.2/include -optc-I/home/cactus/.ghcup/ghc/9.2.8/lib/ghc-9.2.8/time-1.11.1.1/include -optc-I/home/cactus/.ghcup/ghc/9.2.8/lib/ghc-9.2.8/bytestring-0.11.4.0/include -optc-I/home/cactus/.ghcup/ghc/9.2.8/lib/ghc-9.2.8/base-4.16.4.0/include -optc-I/home/cactus/.ghcup/ghc/9.2.8/lib/ghc-9.2.8/ghc-bignum-1.2/include -optc-I/home/cactus/.ghcup/ghc/9.2.8/lib/ghc-9.2.8/include -optc-Wno-error=inline -c utils/hsc2hs/cbits/utils.c -o _build/stageBoot/utils/hsc2hs/build/c/cbits/utils.o -O -H32m ===> Command failed with error code: 1 ghc: unrecognised flag: -this-package-name hsc2hs I don't know where all those references to GHC 9.2.8 come from. I've run `configure` with GHC 9.10.1 on the $PATH and it correctly reports it as the bootstrapping version: Bootstrapping using : ghc which is version : 9.10.1 What am I doing wrong? Gergo

1 2

Cabal woe
by Simon Peyton Jones 11 Jul '24

11 Jul '24

Friends I'm trying to repro #25064 with my development build of GHC. The test case depends on packages `primitive` and `hashtables`. So I try this (see below). Alas, apparently after the `cabal install`, it can't find Prelude. What should I do? I tried removing the "environments" file, whatever that is, which then meant it could find Prelude -- but the libraries were no longer installed. I lack a decent model of what is going on with installing packages for my development builds. Is there a write up anywhere? Thanks Simon bash$ cabal install --lib hashtables primitive --with-compiler $HOME/code/HEAD/$s2 Warning: Unknown/unsupported 'ghc' version detected (Cabal 3.10.1.0 supports 'ghc' version < 9.8): /home/simonpj/code/HEAD/_build/stage1/bin/ghc is version 9.11.20240517 Warning: Unknown/unsupported 'ghc' version detected (Cabal 3.10.1.0 supports 'ghc' version < 9.8): /home/simonpj/code/HEAD/_build/stage1/bin/ghc is version 9.11.20240517 Resolving dependencies... bash$ ~/code/HEAD/$s2 -c T25064.hs Loaded package environment from T25064.hs:1:8: error: [ ]8;;https://errors.haskell.org/messages/GHC-87110 \GHC-87110 ]8;; \] Could not load module ‘Prelude’. It is a member of the hidden package ‘base-4.20.0.0’. Use -v to see a list of the files searched for. | 1 | module Bug where | ^^^ bash$ rm /home/simonpj/.ghc/x86_64-linux-9.11.20240517/environments/default bash$ ~/code/HEAD/$s2 -c T25064.hs T25064.hs:3:1: error: [ ]8;;https://errors.haskell.org/messages/GHC-61948 \GHC-61948 ]8;; \] Could not find module ‘Control.Monad.Primitive’. Perhaps you meant Control.Monad.Writer (from mtl-2.3.1) Use -v to see a list of the files searched for. | 3 | import Control.Monad.Primitive | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ T25064.hs:4:1: error: [ ]8;;https://errors.haskell.org/messages/GHC-87110 \GHC-87110 ]8;; \] Could not find module ‘Data.HashTable.ST.Basic’. Use -v to see a list of the files searched for. | 4 | import qualified Data.HashTable.ST.Basic as H | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

11 20

Sunsetting CentOS support
by Andreas Klebinger 10 Jul '24

10 Jul '24

Hello devs, with CentOS 7 reaching EOL we are demoting it to a Tier 2 platform and will eventually drop support completely. There are no immediate plans to stop supporting it, but we will not allocate any more resources towards support for it and will likely drop support completely should it break in the future. We introduced support for Rocky Linux as replacement for CentOS some time ago, so users who need a RHEL compatible GHC distribution should be able to use GHC packaged for Rocky Linux instead without issues. Best Regards Andreas Klebinger

1 0

Call for Talks: Haskell Implementors' Workshop 2024
by Matthew Pickering 08 Jul '24

08 Jul '24

``` ACM SIGPLAN Haskell Implementors' Workshop https://icfp24.sigplan.org/home/hiw-2024 Milan, Italy, September 2, 2024 Co-located with ICFP 2024 https://icfp24.sigplan.org/ ``` ## Important dates * Deadline: July 19, 2024 (AoE) * Notification: August 2, 2024 * Workshop: September 2, 2024 The 16th Haskell Implementors’ Workshop is to be held alongside ICFP 2024 this year in Milan. It is a forum for people involved in the design and development of Haskell implementations, tools, libraries, and supporting infrastructure to share their work and to discuss future directions and collaborations with others. Talks and/or demos are proposed by submitting an abstract, and selected by a small program committee. There will be no published proceedings. The workshop will be informal and interactive, with open spaces in the timetable and room for ad-hoc discussion, demos, and lightning talks. ## Scope and Target Audience It is important to distinguish the Haskell Implementors’ Workshop from the Haskell Symposium which is also co-located with ICFP 2024. The Haskell Symposium is for the publication of Haskell-related research. In contrast, the Haskell Implementors’ Workshop will have no proceedings – although we will aim to make talk videos, slides, and presented data available with the consent of the speakers. The Implementors’ Workshop is an ideal place to describe a Haskell extension, describe works-in-progress, demo a new Haskell-related tool, or even propose future lines of Haskell development. Members of the wider Haskell community are encouraged to attend the workshop – we need your feedback to keep the Haskell ecosystem thriving. Students working with Haskell are especially encouraged to share their work. The scope covers any of the following topics. There may be some topics that people feel we’ve missed, so by all means submit a proposal even if it doesn’t fit exactly into one of these buckets: * Compilation techniques * Language features and extensions * Type system implementation * Concurrency and parallelism: language design and implementation * Performance, optimization and benchmarking * Virtual machines and run-time systems * Libraries and tools for development or deployment ## Talks We invite proposals from potential speakers for talks and demonstrations. We are aiming for 20-minute talks with 5 minutes for questions and changeovers. We want to hear from people writing compilers, tools, or libraries, people with cool ideas for directions in which we should take the platform, proposals for new features to be implemented, and half-baked crazy ideas. Please submit a talk title and abstract of no more than 300 words. Submissions can be made via HotCRP at https://hiw2024.hotcrp.com until July 19 (anywhere on earth). We will also have a lightning talks session. These have been very well received in recent years, and we aim to increase the time available to them. Lightning talks should be ~7mins and are scheduled on the day of the workshop. Suggested topics for lightning talks are to present a single idea, a work-in-progress project, a problem to intrigue and perplex Haskell implementors, or simply to ask for feedback and collaborators. ## Program Committee * Matthew Pickering (Well-Typed LLP) * David Binder (University of Tübingen) * Gabriella Gonzalez (Mercury) * Sylvain Henry (IOG) * Teofil Camarasu (Tracsis) ## Contact * Matthew Pickering

1 1