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Re: Installing GHC on my MacBook Air
by Simon Peyton Jones 15 Mar '23

15 Mar '23

Redirecting this query to ghc-devs. Can anyone help William? Thanks! Will GHC run on my new MacBook Air? After installing the compiler, my > laptop said its processor was wrong for the binary distribution I chose. If > there is a dmg file for MacOS 12.5.1, please please link your reply to it. > Simon On Tue, 14 Mar 2023 at 23:33, William McEnaney <bill.mcenaney.jr(a)gmail.com> wrote: > Dear Dr. Jones, > > Will GHC run on my new MacBook Air? After installing the compiler, my > laptop said its processor was wrong for the binary distribution I chose. If > there is a dmg file for MacOS 12.5.1, please please link your reply to it. > > Thanks for your help. > > Best, > Bill >

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GHC API documentation
by Harendra Kumar 14 Mar '23

14 Mar '23

Hi, There used to be a GHC API documentation along with other documentation in the GHC release. But I cannot find it any more. For example, in GHC 9.6.1 this link - https://downloads.haskell.org/ghc/9.6.1/docs/libraries/ghc/index.html is broken. What happened to this? Is this now available at some alternate location? -harendra

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Call for Talks: Haskell Implementors' Workshop 2023
by Ryan Scott 08 Mar '23

08 Mar '23

ACM SIGPLAN Haskell Implementors' Workshop https://icfp23.sigplan.org/home/hiw-2023 Seattle, Washington, United States, September 4, 2023 Co-located with ICFP 2023 https://icfp23.sigplan.org/ Important dates --------------- Deadline: July 4, 2023 (AoE) Notification: August 4, 2023 Workshop: September 4, 2023 The 15th Haskell Implementors' Workshop is to be held alongside ICFP 2023 this year in Seattle. 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 short 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 2023. 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, optimisation 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://icfphiw23.hotcrp.com until July 4 (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 ----------------- * Gergő Érdi (Standard Chartered Bank) * Sebastian Graf (Karlsruhe Institute of Technology) * Wen Kokke (University of Strathclyde) * Ryan Scott (Galois, Inc.) * Rebecca Skinner (Mercury) * Li-yao Xia (University of Edinburgh) Contact ------- * Ryan Scott <ryan.gl.scott at gmail.com>

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[ANNOUNCE] GHC 9.6.1-rc1 is now available
by Ben Gamari 03 Mar '23

03 Mar '23

The GHC team is very pleased to announce the availability of the first (and likely final) release candidate of GHC 9.6.1. As usual, binaries and source distributions are available at [downloads.haskell.org](https://downloads.haskell.org/ghc/9.6.1-rc1/). Beginning with GHC 9.6.1, GHC can be built as a cross-compiler to WebAssembly and JavaScript. This is an important step towards robust support for compiling Haskell to the Web, but there are a few caveats to be aware of in the 9.6 series: - Both the Javascript and WebAssembly backends are still at an early stage of development and are present in this release as a technology preview - Using GHC as a cross-compiler is not as easy as we would like it to be; in particular, there are challenges related to Template Haskell - GHC is not yet run-time retargetable; a given GHC binary targets exactly one platform, and both WebAssembly and JavaScript are considered platforms for this purpose. Cross-compilers must be built from source by their users We hope to lift all of these limitations in future releases. Additionally, 9.6.1 will include: - Significant latency improvements in the non-moving garbage collector - Efficient runtime support for delimited continuations - Improvements in compiler error messages - Numerous improvements in the compiler's memory usage See the [release notes][] for a comprehensive accounting of changes in this release. As always, one can find a migration guide to aid in transitioning from older releases on the [GHC Wiki][migration-guide]. We have also recently started extending our release process to cover a wider set of Linux distributions. In particular, we now offer Rocky 8 and Ubuntu 20.04 binary distributions which cover RedHat-derivative and distributions using older `glibc` releases (namely 2.27), respectively. Please do give this release a try and open a [ticket][] if you see anything amiss. If all goes well we expect the final release should be available by late next week. Happy Haskelling, ~ Ben [ticket]: https://gitlab.haskell.org/ghc/ghc/issues/ [migration-guide]: https://gitlab.haskell.org/ghc/ghc/-/wikis/migration/9.6 [release notes]: https://downloads.haskell.org/ghc/9.6.1-rc1/docs/users_guide/9.6.1-notes.ht…

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[Haskell] [ANNOUNCE] GHC 9.2.7 released
by Zubin Duggal 27 Feb '23

27 Feb '23

The GHC developers are happy to announce the availability of GHC 9.2.7. Binary distributions, source distributions, and documentation are available at [downloads.haskell.org](https://downloads.haskell.org/ghc/9.2.7). Download Page: https://www.haskell.org/ghc/download_ghc_9_2_7.html Blog Post: https://www.haskell.org/ghc/blog/20230227-ghc-9.2.7-released.html This release is primarily a bugfix release addressing a few issues found in 9.2.6. These include: * A fix for a bug with the RTS linker being unable to resolve the `setKeepCafs` symbol which started being used by the GHC library in 9.2.6, resulting in code depending on this symbol failing to load in GHCi or via a compile time splice when using a statically linked GHC, such as on Windows (#22961). * A fix a bug with the alignment of RTS data structures that could result in segfaults when compiled with high optimisation settings on certain platforms (#22975 , #22965). * A fix for a bug in the simplifier related to placeholder values (rubbish literals) emitted by the worker/wrapper optimisation leading to -dcore-lint errors and compiler panics in certain cases (#19882, #22914, #23000). * Easier installation of binary distribution on MacOS platforms by changing the installation Makefile to remove the quarantine attribute when installing. * ... and a few more. See the [release notes] for a full accounting. 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 compiling, - Zubin [ticket]: https://gitlab.haskell.org/ghc/ghc/-/issues/new [release notes]: https://downloads.haskell.org/~ghc/9.2.7/docs/html/users_guide/9.2.7-notes.…

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Status of ghcup?
by Dominick Samperi 22 Feb '23

22 Feb '23

I watched an interesting YouTube video explaining how to install and use the Haskell extension in VS code, but the information appears to be obsolete, because there is no mention of ghcup, and ghcup is now required, along with a new version of the Haskell extension (the old one is labeled "legacy"). Unfortunately, I could not install ghcup on Windows due to obscure PowerShell security issues, or missing libraries in MSYS. While wrestling with this problem I discovered that Unix tools from Rtools must not be in PATH while working with Stack, probably due to incompatible MSYS versions. But removing Rtools from PATH does not resolve the ghcup installation problems. Any tips on ghcup installation under Windows would be appreciated. Thanks, Dominick

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Using GHC API with multiple targets
by Eternal Recursion 19 Feb '23

19 Feb '23

Hi Everyone! I'm new here, trying to learn the GHC API. using 944 with cabal 3.8.1.0. How do I correctly set a GHC Session's DynFlags (and/or other properties) to ensure local libraries imported by the main target are resolved properly at compile time? What flags need to be set so that GHC is able to load/analyze/compile all relevant Libraries in a package? This is my current code: withPath :: FilePath -> IO () withPath target = do let targetDir = takeDirectory target let targetFile = takeFileName target listing <- listDirectory targetDir let imports = filter (\f -> takeExtension f == ".hs") listing print imports let moduleName = mkModuleName targetFile g <- defaultErrorHandler defaultFatalMessager defaultFlushOut $ runGhc (Just libdir) $ do initGhcMonad (Just libdir) dynflags <- getSessionDynFlags setSessionDynFlags $ dynflags { ghcLink = LinkInMemory , ghcMode = CompManager , backend = Interpreter , mainModuleNameIs = moduleName , workingDirectory = Just targetDir , importPaths = [targetDir] ++ importPaths dynflags } targets <- mapM (\t -> guessTarget t Nothing Nothing) imports setTargets targets setContext [ IIDecl $ simpleImportDecl (mkModuleName "Prelude") ] load LoadAllTargets liftIO . print . ppr =<< getTargets getModuleGraph putStrLn "Here we go!" print $ ppr $ mgModSummaries g putStrLn "☝️ " However, when I run it (passing to example/app/Main.hs, in which directory are Lib.hs and Lib2.hs, the latter being imported into Main), I get: $ cabal run cli -- example/app/Main.hs Up to date ["Main.hs","Lib.hs","Lib2.hs"] [main:Main.hs, main:Lib.hs, main:Lib2.hs] Here we go! [ModSummary { ms_hs_hash = 23f9c4415bad851a1e36db9d813f34be ms_mod = Lib, unit = main ms_textual_imps = [(, Prelude)] ms_srcimps = [] }, ModSummary { ms_hs_hash = e1eccc23af49f3498a5a9566e63abefd ms_mod = Lib2, unit = main ms_textual_imps = [(, Prelude)] ms_srcimps = [] }, ModSummary { ms_hs_hash = 5f6751d7f0d5547a1bdf39af84f8c07f ms_mod = Main, unit = main ms_textual_imps = [(, Prelude), (, Lib2)] ms_srcimps = [] }] ☝ example/app/Main.hs:4:1: error: Could not find module ‘Lib2’ Use -v (or `:set -v` in ghci) to see a list of the files searched for. | 4 |import qualified Lib2 as L2 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ cli: example/app/Main.hs:4:1: error: Could not find module `Lib2' Use -v (or `:set -v` in ghci) to see a list of the files searched for. What do I need to do differently to make this work? I have a local Cabal file I could use, but to know what I need out of it, I need to understand the minimum required info to get this to work. TIA! Sincerely, Bob Sent with [Proton Mail](https://proton.me/) secure email.

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[ANNOUNCE] GHC 9.6.1-alpha3 is now available
by Ben Gamari 16 Feb '23

16 Feb '23

The GHC team is very pleased to announce the availability of GHC 9.6.1-alpha3. As usual, binaries and source distributions are available at downloads.haskell.org: https://downloads.haskell.org/ghc/9.6.1-alpha3/ Beginning with GHC 9.6.1, GHC can be built as a cross-compiler to WebAssembly and JavaScript. This is an important step towards robust support for compiling Haskell to the Web, but there are a few caveats to be aware of in the 9.6 series: - Both the Javascript and WebAssembly backends are still at an early stage of development and are present in this release as a technology preview - Using GHC as a cross-compiler is not as easy as we would like it to be; in particular, there are challenges related to Template Haskell - GHC is not yet run-time retargetable; a given GHC binary targets exactly one platform, and both WebAssembly and JavaScript are considered platforms for this purpose. Cross-compilers must be built from source by their users We hope to lift all of these limitations in future releases. Additionally, 9.6.1 will include: - Significant latency improvements in the non-moving garbage collector - Efficient runtime support for delimited continuations - Improvements in compiler error messages - Numerous improvements in the compiler's memory usage See the [release notes] for a comprehensive accounting of changes in this release. As always, one can find a [migration guide] to aid in transitioning from older releases on the GHC Wiki. We have also recently started extending our release process to cover a wider set of Linux distributions. In particular, we now offer Rocky 8 and Ubuntu 20.04 binary distributions which cover RedHat-derivative and distributions using older `glibc` releases (namely 2.27), respectively. Please do give this release a try and open a [ticket] if you see anything amiss. Cheers, - Ben [ticket]: https://gitlab.haskell.org/ghc/ghc/issues/ [migration guide]: https://gitlab.haskell.org/ghc/ghc/-/wikis/migration/9.6 [release notes]: https://downloads.haskell.org/ghc/9.6.1-alpha3/docs/users_guide/9.6.1-notes…

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`ideclImplicit` in compiler/GHC/Iface/Ext/Ast.hs?
by Brandon Allbery 13 Feb '23

13 Feb '23

I'm researching a potential GHC proposal to allow "Prelude-like" imports, which in practice means silencing warnings about implicit use of symbols from them (-Wmissing-import-lists and similar). So far, it looks like `ideclImplicit` does almost exactly what I want and all I need is syntax to set it on imports other than the implicit Prelude import. With one notable exception: around compiler/GHC/Iface/Ext/Ast.hs line 326 (HEAD as of Saturday) there is a use that appears to intend to exclude the implicit Prelude import, without conditionalizing on Prelude like e.g. compiler/GHC/Tc/Module.hs lines 1685--1687. I have several questions about it. 1. The implicit import, but not explicit imports, are excluded from the extended .hi file? This seems wrong-ish to me; I'm wondering if it's actually looking to do something else such as strip it down to only the symbols in use. But I don't really know what the code here is supposed to do. 2. Should other "implicit" imports also be excluded the same way? -- brandon s allbery kf8nh allbery.b(a)gmail.com

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Getting Info Table Profiling to the finish line
by Hécate 13 Feb '23

13 Feb '23

Hello fellow devs, I am indexing the work necessary to bring Info Table Profiling to the finish line: Seamless for the user to employ. Some of the tickets refer to external ticket trackers, they have been marked as FOREIGN. Their counterpart tickets will be opened there when the situation unlocks on our side. The epic is at https://gitlab.haskell.org/groups/ghc/-/epics/3 Please feel free to link future tickets that are related to this newer, better way of doing space profiling. My thanks to Matthew Pickering, David Eichmann, and Ben Gamari. Cheers, Hécate (with a project manager hat on, apparently!) -- Hécate ✨ 🐦: @TechnoEmpress IRC: Hecate WWW: https://glitchbra.in RUN: BSD

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