March 2023 - ghc-devs

[ANNOUNCE] GHC 9.6.1 is now available
by Ben Gamari 02 Apr '23

02 Apr '23

The GHC team is very pleased to announce the availability 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/ 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 includes: - 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. Thanks to everyone who has contributed code, documentation, testing, and tickets to this release process. As this release represents upstream GHC's first step towards supporting web targets, we are very excited to have this release out the door! 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/docs/users_guide/9.6.1-notes.html

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GHC 9.2.7 on FreeBSD - HSC2HS_EXTRA issue
by Martin Baulig 30 Mar '23

30 Mar '23

Hello, I am a FreeBSD user, running FreeBSD 13.1 with Clang 13 and GCC 12.2, and still fairly new to the Haskell Platform. When I tried to upgrade a hobby project to Stackage's latest LTS 20.15, I realized that neither the GHC 9.2.6 nor the GHC 9.2.7 binary packages from GHCUP work anymore. There are two issues - and I wrote a detailed article about my investigation on Medium: https://medium.com/@martin.baulig/ghc-9-2-7-on-freebsd-22afab71c715 The first one is a trivial one-line change - in hadrian/src/Rules/BinaryDist.hs, we need to change > ( "HSC2HS_EXTRA=\"" <> unwords ccArgs <> unwords ldFlags <> "\"" into > ( "HSC2HS_EXTRA=\"" <> unwords (ccArgs <> ldFlags) <> "\"" Otherwise, this will break when both ccArgs and ldFlags are non-empty: > HSC2HS_EXTRA="--cflag=--target=x86_64-portbld-freebsd--lflag=--target=x86_64-portbld-freebsd --lflag=-fuse-ld=lld" Unfortunately, this is not quite it just yet. The problem is that Clang supports the --target= argument, but GCC does not - and it looks like Cabal insists on always invoking hsc2hs with an explicit --cc= argument. Overriding that in ~/.cabal/config doesn't work either - because then Cabal passes "-pgmc /usr/bin/cc" to GHC, but no "-pgma" and GHC tries to invoke GCC for assembling with a Clang-only argument. I am a bit lost here now about what the correct path forward is, but would very much like to help fixing this problem, so I created an account on gitlab.haskell.org to report this issue, but got a message saying that it is awaiting admin approval. Looking a bit further in the documentation for new contributors, I saw a comment suggesting I should post on this mailing list and ask for approval. Could an admin please have a look at that? My user name is my last name in lowercase, baulig. Looking forward to hear back from you, Martin

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Windows/R issue with FFI
by Dominick Samperi 30 Mar '23

30 Mar '23

Hello, FFI code that used to work now fails under Windows (still seems to work under Ubuntu), and I wonder if anybody has seen anything like this and can provide some pointers... The code uses FFI to fetch information from the R side like R_NilValue, using something like this; -- Fetch R's R_NilValue... foreign import ccall unsafe "&R_NilValue" r_NilValue_ptr :: Ptr R_EXP r_NilValue :: IO R_EXP r_NilValue = peek r_NilValue_ptr rNilValue1 :: IO REXP rNilValue1 = do x <- r_NilValue traceShow("addr=",x) extREXP x Under Windows the address displayed is obviously bad, and this causes the app to crash. This does not happen under Linux (Ubuntu). Now, replace the line containing peek with r_NilValue = trace "PEEK" peek r_NilValue_ptr The address is now valid! It seems that adding the trace "PEEK" adds some delay and somehow resolves the problem. This problem is intermittent, so it is hard to come up with a simple example that fails every time. A little background: R_NilValue is a pointer to a SEXP that is not initialized until an embedded instance of R is initialized, and the code above is not triggered until this happens. Perhaps there is a race condition between the time R initializes itself and Haskell performs the peek? I don't think R_NilValue is garbage collected once initialized. Any tips would be appreciated. Dominick

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Understanding how warnings on unused functions work
by Razetime 27 Mar '23

27 Mar '23

This message is related to a feature in the futhark compiler <https://github.com/diku-dk/futhark/issues/550>, which is a language with a similar module system. I am trying to create a tool to detect unused top-level functions in Futhark, and I have been looking in the ghc codebase to find out how it does so. So far I have found these areas: 1. warning flag <https://gitlab.haskell.org/ghc/ghc/-/blob/master/compiler/GHC/Driver/Flags.…> 2. WarnUnusedTopBinds <https://gitlab.haskell.org/ghc/ghc/-/blob/master/compiler/GHC/Rename/Utils.…> The project is a bit too big for my machine to take, so HLS is not helping me with finding where the computation of unused bindings (specifically functions) is done. I would like some help with finding where ghc does this computation, and maybe some help with the naming conventions of the code. Thanks in advance.

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Buy-in for technical proposal 47 which affect GHC devs
by Laurent P. René de Cotret 25 Mar '23

25 Mar '23

Dear GHC developers, In recent weeks, John Ericson has fine-tuned a Haskell Foundation Technical Proposal to split `base` into two libraries: `ghc-base` and `base`, the latter simply re-exporting everything for `ghc-base` (for now). You can read about the rationale and specifics more in details in the proposal itself: https://github.com/haskellfoundation/tech-proposals/pull/47 Note that this proposal has recently been streamlined into a form which is more focused than its initial state, and might be worth a re-read. The Haskell Foundation Technical Working Group has reached a consensus that this work will benefit the Haskell community. Moreover, the Haskell Foundation has agreed to spend some of its resources to implement this proposal, which would start by ensuring the completion of MR7898 (https://gitlab.haskell.org/ghc/ghc/-/merge_requests/7898) This work will affect GHC developers. Therefore, the Technical Working Group would like to get buy-in from the GHC developers before formally accepting this proposal. Best regards, Laurent P. René de Cotret on behalf of the Haskell Foundation Technical Working Group

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GitLab partial outage - attempting to mitigate
by Bryan Richter 20 Mar '23

20 Mar '23

I am seeing a few different problems with the GitLab server right now. I am gonna try to mitigate the issues, so the server might be unavailable for a few short periods.

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Re: CI
by Bryan Richter 19 Mar '23

19 Mar '23

Spam detection software, running on the system "mail.haskell.org", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see @@CONTACT_ADDRESS@@ for details. Content preview: I'm back at my computer and am investigating. I don't see the problem I feared, but I do see some anomalies. I'll update once it's back to normal. On Sat, 18 Mar 2023 at 17:55, Bryan Richter <bryan(a)haskell.foundation> wrote: [...] Content analysis details: (5.8 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record 5.0 UNWANTED_LANGUAGE_BODY BODY: Message written in an undesired language 0.0 HTML_MESSAGE BODY: HTML included in message 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% [score: 0.5000] 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid The original message was not completely plain text, and may be unsafe to open with some email clients; in particular, it may contain a virus, or confirm that your address can receive spam. If you wish to view it, it may be safer to save it to a file and open it with an editor.

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CI
by Simon Peyton Jones 18 Mar '23

18 Mar '23

All GHC CI pipelines seem stalled, sadly e.g. https://gitlab.haskell.org/ghc/ghc/-/merge_requests/10123/pipelines Can someone unglue it? Thanks! Simon

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Re: Installing GHC on my MacBook Air
by George Colpitts 17 Mar '23

17 Mar '23

Type the following at the command line: xcode-select --install and then try ghci again. I'm not sure what you mean by "the software" in the phrase "Should I delete and reinstall the software you told me to install?" but in any case don't delete anything. Please try to be as specific as possible. When you first encounter a problem you should Google for a solution. If that doesn't work you can send mail to me but also cc ghc-devs(a)haskell.org and glasgow-haskell-users(a)haskell.org Cheers George On Thu, Mar 16, 2023 at 11:09 PM William McEnaney < bill.mcenaney.jr(a)gmail.com> wrote: > Hi, George, > > Sorry to bother you. Though ghc seems to run properly, here's what ghci > prints on my screen. What mistake did I make? Should I delete and reinstall > the software you told me to install? > > "GHCi, version 9.4.4: https://www.haskell.org/ghc/ :? for help > > xcrun: error: invalid active developer path > (/Library/Developer/CommandLineTools), missing xcrun at: > /Library/Developer/CommandLineTools/usr/bin/xcrun > > `gcc' failed in phase `gcc'. (Exit code: 1) > > williammcenaney@Williams-Air bin" > > > Thanks. > > > Bill > > > Bill > > On Wed, Mar 15, 2023 at 7:59 AM George Colpitts <george.colpitts(a)gmail.com> > wrote: > >> Hi Bill >> >> Yes,GHC will run on your new MacBook Air. The cpu in that is Apple >> Silicon , the aarch64-apple-darwin platform. Older Macs run on Intel chips, >> the x86_64-apple-darwin platform. >> >> I'm not sure how you installed the compiler. I believe the standard way >> is described on https://www.haskell.org/ghcup/. Can you tell us how you >> installed it? >> >> Thanks >> George >> >> On Wed, Mar 15, 2023 at 8:22 AM Simon Peyton Jones < >> simon.peytonjones(a)gmail.com> wrote: >> >>> 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 >>>> >>> _______________________________________________ >>> ghc-devs mailing list >>> ghc-devs(a)haskell.org >>> http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs >>> >>

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Re: Installing GHC on my MacBook Air
by George Colpitts 15 Mar '23

15 Mar '23

Somehow I missed that it is now working for you. Great! Definitely no need to report a bug. Haskell is a great language. Enjoy! Cheers George On Wed, Mar 15, 2023 at 3:07 PM William McEnaney <bill.mcenaney.jr(a)gmail.com> wrote: > Hi, George, > > Now that the compiler runs, maybe I don't need to report a bug. > ... > Thanks for everything. > > Bill > > On Wed, Mar 15, 2023 at 1:17 PM George Colpitts <george.colpitts(a)gmail.com> > wrote: > >> Hi Bill, >> >> It's easy to forget to do replay all in gmail but it's important to do so >> in these emails. >> >> In your original email you wrote: >> >> 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. >> >> >> Can you confirm that you no longer have the problem "of processor was >> wrong for the binary distribution I chose." ? >> >> My understanding is that after that you got the error: >> >> libHSterminfo-0.4.1.5-ghc9.4.4.dylib” can’t be opened because Apple >> cannot check it for malicious software. >> >> I then suggested you had encountered >> https://gitlab.haskell.org/ghc/ghc/-/issues/21506#note_447206 and I >> suggested you do: >> >> rm -fr /usr/local/bin/ghc* >> rm -fr /usr/local/lib/ghc* >> ./configure >> sudo xattr -rc . >> sudo make install >> >> >> You said you did and got a warning "that some program wanted to access my >> photos when I don't have any." >> >> Can you repeat those steps and cut and paste your terminal session into >> an email? >> >> Unfortunately I am too busy to continue replying but with the above I >> think somebody will be able to help you. >> >> Cheers, >> George >> >> >> On Wed, Mar 15, 2023 at 1:59 PM William McEnaney < >> bill.mcenaney.jr(a)gmail.com> wrote: >> >>> Hi, George, >>> >>> I'd be happy to do that for you. But I'm sure I can recall the >>> information a GHC maintainer would need. >>> >>> Best, >>> Bill >>> >>> On Wed, Mar 15, 2023 at 12:41 PM George Colpitts < >>> george.colpitts(a)gmail.com> wrote: >>> >>>> Hi William >>>> >>>> I think it's best if you submit a bug as described here >>>> <https://gitlab.haskell.org/ghc/ghc/-/wikis/report-a-bug> >>>> >>>> Whether in email or in the bug report it is critical that you >>>> describe how the reader can reproduce the bug, i.e. starting from the >>>> beginning, describe what you did and what error message(s) you got. >>>> >>>> Regards, >>>> George >>>> >>>> >>>> On Wed, Mar 15, 2023 at 1:34 PM William McEnaney < >>>> bill.mcenaney.jr(a)gmail.com> wrote: >>>> >>>>> Hi, George, >>>>> >>>>> Yes, I did. But I must have made a mistake. After I pasted them into a >>>>> Terminal window, the machine warned me that some program wanted to access >>>>> my photos when I don't have any. >>>>> >>>>> >>>>> On Wed, Mar 15, 2023 at 12:26 PM George Colpitts < >>>>> george.colpitts(a)gmail.com> wrote: >>>>> >>>>>> Bill >>>>>> >>>>>> For your latest problem >>>>>> >>>>>> libHSterminfo-0.4.1.5-ghc9.4.4.dylib” can’t be opened because Apple >>>>>> cannot check it for malicious software. >>>>>> >>>>>> Did you try what I wrote in my last email: >>>>>> >>>>>> rm -fr /usr/local/bin/ghc* >>>>>> rm -fr /usr/local/lib/ghc* >>>>>> ./configure >>>>>> sudo xattr -rc . >>>>>> sudo make install >>>>>> >>>>>> George >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> On Wed, Mar 15, 2023 at 1:20 PM William McEnaney < >>>>>> bill.mcenaney.jr(a)gmail.com> wrote: >>>>>> >>>>>>> Hi, everyone, >>>>>>> >>>>>>> Thank you for the help. Someone will tell me how to solve >>>>>>> the problem, I hope because it stumped me. >>>>>>> >>>>>>> Bill >>>>>>> >>>>>>> On Wed, Mar 15, 2023 at 12:10 PM Brandon Allbery < >>>>>>> allbery.b(a)gmail.com> wrote: >>>>>>> >>>>>>>> That seems unlikely; it would report a permission error in that >>>>>>>> case, >>>>>>>> not that it had the wrong architecture. >>>>>>>> >>>>>>>> On Wed, Mar 15, 2023 at 12:04 PM George Colpitts >>>>>>>> <george.colpitts(a)gmail.com> wrote: >>>>>>>> > >>>>>>>> > Hi Bill >>>>>>>> > >>>>>>>> > I'm cc'ing GHC dev and GHC users as someone else may have a >>>>>>>> better answer, catch a mistake I made etc. Please don't delete them. >>>>>>>> > >>>>>>>> > I believe you have encountered >>>>>>>> https://gitlab.haskell.org/ghc/ghc/-/issues/21506#note_447206 >>>>>>>> > >>>>>>>> > I believe the way to fix this is to do the following: >>>>>>>> > >>>>>>>> > rm -fr /usr/local/bin/ghc* >>>>>>>> > rm -fr /usr/local/lib/ghc* >>>>>>>> > ./configure >>>>>>>> > sudo xattr -rc . >>>>>>>> > sudo make install >>>>>>>> > >>>>>>>> > >>>>>>>> > However I am unsure why you are encountering this as the issue is >>>>>>>> supposed to have been fixed. >>>>>>>> > >>>>>>>> > Cheers >>>>>>>> > George >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> > On Wed, Mar 15, 2023 at 11:21 AM William McEnaney < >>>>>>>> bill.mcenaney.jr(a)gmail.com> wrote: >>>>>>>> >> >>>>>>>> >> Hi, George, >>>>>>>> >> >>>>>>>> >> I got this message when I ran make install with the sudo >>>>>>>> command. What should I do? >>>>>>>> >> >>>>>>>> >> libHSterminfo-0.4.1.5-ghc9.4.4.dylib” can’t be opened because >>>>>>>> Apple cannot check it for malicious software. >>>>>>>> >> >>>>>>>> >> >>>>>>>> >> What should I do now? >>>>>>>> >> >>>>>>>> >> >>>>>>>> >> Thanks. >>>>>>>> >> >>>>>>>> >> >>>>>>>> >> Bill >>>>>>>> >> >>>>>>>> >> >>>>>>>> >> >>>>>>>> >> >>>>>>>> >> On Wed, Mar 15, 2023 at 9:29 AM William McEnaney < >>>>>>>> bill.mcenaney.jr(a)gmail.com> wrote: >>>>>>>> >>> >>>>>>>> >>> Hi George, >>>>>>>> >>> >>>>>>>> >>> Thank you for your reply. I forget what I did to install it. >>>>>>>> But the compiler and other ghc-related programs live in /usr/local/bin. >>>>>>>> Since I installed the wrong binaries, I changed the directory to >>>>>>>> /usr/local/bin and tried to empty that directory with rm -rf ghc*.*, but >>>>>>>> that didn't delete anything. So I wonder whether I'll need to remove those >>>>>>>> programs before reinstalling ghc. >>>>>>>> >>> >>>>>>>> >>> Thanks for your help, too. >>>>>>>> >>> >>>>>>>> >>> Best, >>>>>>>> >>> Bill >>>>>>>> >>> >>>>>>>> >>> On Wed, Mar 15, 2023 at 7:59 AM George Colpitts < >>>>>>>> george.colpitts(a)gmail.com> wrote: >>>>>>>> >>>> >>>>>>>> >>>> Hi Bill >>>>>>>> >>>> >>>>>>>> >>>> Yes,GHC will run on your new MacBook Air. The cpu in that is >>>>>>>> Apple Silicon , the aarch64-apple-darwin platform. Older Macs run on Intel >>>>>>>> chips, the x86_64-apple-darwin platform. >>>>>>>> >>>> >>>>>>>> >>>> I'm not sure how you installed the compiler. I believe the >>>>>>>> standard way is described on https://www.haskell.org/ghcup/. Can >>>>>>>> you tell us how you installed it? >>>>>>>> >>>> >>>>>>>> >>>> Thanks >>>>>>>> >>>> George >>>>>>>> >>>> >>>>>>>> >>>> On Wed, Mar 15, 2023 at 8:22 AM Simon Peyton Jones < >>>>>>>> simon.peytonjones(a)gmail.com> wrote: >>>>>>>> >>>>> >>>>>>>> >>>>> 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 >>>>>>>> >>>>> >>>>>>>> >>>>> _______________________________________________ >>>>>>>> >>>>> ghc-devs mailing list >>>>>>>> >>>>> ghc-devs(a)haskell.org >>>>>>>> >>>>> http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs >>>>>>>> > >>>>>>>> > _______________________________________________ >>>>>>>> > ghc-devs mailing list >>>>>>>> > ghc-devs(a)haskell.org >>>>>>>> > http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> -- >>>>>>>> brandon s allbery kf8nh >>>>>>>> allbery.b(a)gmail.com >>>>>>>> >>>>>>>

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