- ghc-devs - Haskell.org

HEADS UP: Tickets have been triaged a bit
by Austin Seipp 23 Dec '14

23 Dec '14

Hi *, As many of you will probably notice, I have bulk modified a lot of Trac tickets and moved their milestone out. You might be wondering why; the reasoning is that since 7.10.1 RC1 is out (see other email), we need to start prioritizing what gets done. So, I moved all tickets that were a) set to 7.10.1 milestone, b) not closed, and c) had below 'high priority', to the 7.12.1 milestone. There are some tickets in 'normal' that probably should be moved back. If you're CC'd on a ticket and think it should be fixed for 7.10.1, please: - Set the milestone back to 7.10.1 - And if you can, take ownership! GHC HQ will probably only have time to organize efforts to take on the most high priority tickets - so any help you can offer is always appreciated. You can see the current list of tickets here. We'll put notes on the page at the top as time goes on to keep people up to date. https://ghc.haskell.org/trac/ghc/wiki/Status/GHC-7.10.1 -- Regards, Austin Seipp, Haskell Consultant Well-Typed LLP, http://www.well-typed.com/

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Phabricator builds with haddock changes fail
by Alan & Kim Zimmerman 23 Dec '14

23 Dec '14

It seems that phabricator is not picking up haddock commits for builds. I rebased my D538 diff, with matching haddock submodule Subproject commit 54c5e7cd0b5844712301cacc826a6b112dbc1090 However, the build fails with an error in haddock which is explictly patched in the haddock repo. Up until last week this process worked fine, and was recently recommended on this mailing list. Has something changed now that it is a RC? Failing build: https://phabricator.haskell.org/harbormaster/build/2762/ Changed line in haddock branch https://github.com/haskell/haddock/commit/54c5e7cd0b5844712301cacc826a6b112… Regards Alan

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GHC 7.10.1 / cabal-install 1.22 Ubuntu-PPA pre-RC snapshots available!
by Herbert Valerio Riedel 23 Dec '14

23 Dec '14

To early adopters & multi-ghc-travis users, I've uploaded pre-RC snapshots for GHC 7.10.1 and cabal-install 1.22 to my GHC PPA[1], so you can start extending your .travis.yml files w/ CABALVER=1.22 GHCVER=7.10.1 There are no official RCs yet for GHC 7.10/cabal-install 1.22, these are merely snapshots from the respective Git branches which I'll keep updating regularly (every 1-3 days) till the final proper release for GHC 7.10.1 and cabal-install 1.22.0.0 occur, at which point those packages (`ghc-7.10-*` & `cabal-install-1.22`) will install the final release versions. The usual official release-candidates (including respective announcements) for GHC & cabal will follow soon. So please, help us finding issues/bugs with these pre-RC snapshots of GHC & cabal-install. Obviously, it's desirable to become aware of any serious issues ASAP, as opposed to shortly before the planned final release date... As these are Git snapshots, when reporting bugs/issues, please also provide the snapshot's Git commit id (which uniquely identifies the GHC source-tree state), which can be queried via a new GHC CLI option, e.g.: $ ghc --print-project-git-commit-id a8c556dfca3eca5277615cc2bf9d6c8f1f143c9a Here's an example build using 7.10.1 to show those packages actually work: https://travis-ci.org/haskell/unix/builds/44919992 [1]: https://github.com/hvr/multi-ghc-travis https://launchpad.net/~hvr/+archive/ubuntu/ghc Cheers, hvr PS: If you happen to run into compile errors for Hackage packages which claim to work with GHC 7.10.1 (e.g. by allowing `base-4.8`), I'd be interested to hear about it.

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stg_init_finish
by Ben Gamari 23 Dec '14

23 Dec '14

Hi Simon, A few of us are puzzling over a cross-compilation bug, #9920. stg_init_finish appears to be loading a zero Sp from the saved thread state. None of us have been able to figure out how execution makes it to stg_init_finish. The only references to the symbol are its definition in StgStartup.cmm and a header declaration in MiscClosures.h. Could you perhaps shed some light on how execution is supposed to flow during RTS initialization? Cheers, - Ben

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Triggering a Harbourmaster build on a given commit
by Dr. ERDI Gergo 22 Dec '14

22 Dec '14

Hi, Given a concrete commit on a non-master branch (e.g. https://phabricator.haskell.org/rGHC20acaa7785d910d36d46c4eae9e9cce4000635d1) how do I manually trigger a Harbourmaster build + validation? Thanks, Gergo -- .--= ULLA! =-----------------. \ http://gergo.erdi.hu \ `---= gergo(a)erdi.hu =-------' A man's best friend is his dogma.

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Fatal: Reference is not a tree
by Simon Peyton Jones 22 Dec '14

22 Dec '14

Dear devs When doing 'arc patch' I got fatal: reference is not a tree: d809f9d656780273f4f79e7a9fb934f783f79702 Unable to checkout 'd809f9d656780273f4f79e7a9fb934f783f79702' in submodule path 'utils/haddock' Should I worry? Simon simonpj@cam-05-unx:~/code/HEAD-2$ arc patch D202 arc patch D202 You have untracked files in this working copy. Working copy: /home/simonpj/code/HEAD-2/ Untracked files in working copy: flat-skol-diff foo foo2 index.html.1 index.html.2 index.html.3 resume spj-patch spj-patch-save testsuite/mk/ghcconfig_home_simonmar_fp_bin_x86_64-unknown-linux_ghc.mk testsuite/tests/simplCore/should_compile/T8538.hs testsuite/tests/simplCore/should_compile/T9073.hs tmp-patch untch-patch Since you don't have '.gitignore' rules for these files and have not listed them in '.git/info/exclude', you may have forgotten to 'git add' them to your commit. Do you want to amend these files to the commit? [y/N] n n Created and checked out branch arcpatch-D202. Checking patch compiler/basicTypes/MkId.hs... Checking patch compiler/basicTypes/NameEnv.hs... Checking patch compiler/basicTypes/VarSet.hs... Checking patch compiler/deSugar/DsMeta.hs... Checking patch compiler/hsSyn/Convert.hs... Checking patch compiler/hsSyn/HsDecls.hs... Checking patch compiler/hsSyn/PlaceHolder.hs... Checking patch compiler/iface/BuildTyCl.hs... Checking patch compiler/iface/IfaceSyn.hs... Checking patch compiler/iface/MkIface.hs... Checking patch compiler/iface/TcIface.hs... Checking patch compiler/main/GHC.hs... Checking patch compiler/main/HscTypes.hs... Checking patch compiler/parser/ApiAnnotation.hs... Checking patch compiler/parser/Parser.y... Checking patch compiler/parser/RdrHsSyn.hs... Checking patch compiler/prelude/TysPrim.hs... Checking patch compiler/rename/RnSource.hs... Checking patch compiler/rename/RnTypes.hs... Checking patch compiler/typecheck/FamInst.hs... Checking patch compiler/typecheck/TcEnv.hs... Checking patch compiler/typecheck/TcEvidence.hs... Checking patch compiler/typecheck/TcInstDcls.hs... Checking patch compiler/typecheck/TcRnDriver.hs... Checking patch compiler/typecheck/TcRnMonad.hs... Checking patch compiler/typecheck/TcSplice.hs... Checking patch compiler/typecheck/TcTyClsDecls.hs... Checking patch compiler/typecheck/TcTypeNats.hs... Checking patch compiler/typecheck/TcValidity.hs... Checking patch compiler/types/CoAxiom.hs... Checking patch compiler/types/Coercion.hs... Checking patch compiler/types/FamInstEnv.hs... Checking patch compiler/types/Kind.hs... Checking patch compiler/types/OptCoercion.hs... Checking patch compiler/types/TyCon.hs... Checking patch compiler/types/TypeRep.hs... Checking patch compiler/types/TypeRep.hs-boot... Checking patch compiler/utils/Outputable.hs... Checking patch compiler/vectorise/Vectorise/Generic/PADict.hs... Checking patch compiler/vectorise/Vectorise/Generic/PAMethods.hs... Checking patch compiler/vectorise/Vectorise/Type/Env.hs... Checking patch compiler/vectorise/Vectorise/Utils/PADict.hs... Checking patch libraries/template-haskell/Language/Haskell/TH.hs... Checking patch libraries/template-haskell/Language/Haskell/TH/Lib.hs... Checking patch libraries/template-haskell/Language/Haskell/TH/Ppr.hs... Checking patch libraries/template-haskell/Language/Haskell/TH/PprLib.hs... Checking patch libraries/template-haskell/Language/Haskell/TH/Syntax.hs... Checking patch testsuite/tests/ghci/scripts/T6018ghci.script... Checking patch testsuite/tests/ghci/scripts/T6018ghci.stdout... Checking patch testsuite/tests/ghci/scripts/T6018ghcifail.script... Checking patch testsuite/tests/ghci/scripts/T6018ghcifail.stderr... Checking patch testsuite/tests/ghci/scripts/T6018ghcirnfail.script... Checking patch testsuite/tests/ghci/scripts/T6018ghcirnfail.stderr... Checking patch testsuite/tests/ghci/scripts/all.T... Checking patch testsuite/tests/rename/should_fail/T6018rnfail.hs... Checking patch testsuite/tests/rename/should_fail/T6018rnfail.stderr... Checking patch testsuite/tests/rename/should_fail/all.T... Checking patch testsuite/tests/typecheck/should_compile/T6018.hs... Checking patch testsuite/tests/typecheck/should_compile/T6018.hs-boot... Checking patch testsuite/tests/typecheck/should_compile/T6018.stderr... Checking patch testsuite/tests/typecheck/should_compile/T6018a.hs... Checking patch testsuite/tests/typecheck/should_compile/all.T... Checking patch testsuite/tests/typecheck/should_fail/T6018Afail.hs... Checking patch testsuite/tests/typecheck/should_fail/T6018Bfail.hs... Checking patch testsuite/tests/typecheck/should_fail/T6018Cfail.hs... Checking patch testsuite/tests/typecheck/should_fail/T6018Dfail.hs... Checking patch testsuite/tests/typecheck/should_fail/T6018fail.hs... Checking patch testsuite/tests/typecheck/should_fail/T6018fail.stderr... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed1.hs... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed1.stderr... /tmp/62xml2q9glk44k0o/14486-pNEMxf:4283: new blank line at EOF. + Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed2.hs... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed2.stderr... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed3.hs... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed3.stderr... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed4.hs... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed4.stderr... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed5.hs... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed5.stderr... /tmp/62xml2q9glk44k0o/14486-pNEMxf:4399: new blank line at EOF. + Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed6.hs... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed6.stderr... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed7.hs... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed7.stderr... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed8.hs... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed8.stderr... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed9.hs... Checking patch testsuite/tests/typecheck/should_fail/T6018failclosed9.stderr... Checking patch testsuite/tests/typecheck/should_fail/all.T... Checking patch utils/haddock... warning: unable to rmdir utils/haddock: Directory not empty Applied patch compiler/basicTypes/MkId.hs cleanly. Applied patch compiler/basicTypes/NameEnv.hs cleanly. Applied patch compiler/basicTypes/VarSet.hs cleanly. Applied patch compiler/deSugar/DsMeta.hs cleanly. Applied patch compiler/hsSyn/Convert.hs cleanly. Applied patch compiler/hsSyn/HsDecls.hs cleanly. Applied patch compiler/hsSyn/PlaceHolder.hs cleanly. Applied patch compiler/iface/BuildTyCl.hs cleanly. Applied patch compiler/iface/IfaceSyn.hs cleanly. Applied patch compiler/iface/MkIface.hs cleanly. Applied patch compiler/iface/TcIface.hs cleanly. Applied patch compiler/main/GHC.hs cleanly. Applied patch compiler/main/HscTypes.hs cleanly. Applied patch compiler/parser/ApiAnnotation.hs cleanly. Applied patch compiler/parser/Parser.y cleanly. Applied patch compiler/parser/RdrHsSyn.hs cleanly. Applied patch compiler/prelude/TysPrim.hs cleanly. Applied patch compiler/rename/RnSource.hs cleanly. Applied patch compiler/rename/RnTypes.hs cleanly. Applied patch compiler/typecheck/FamInst.hs cleanly. Applied patch compiler/typecheck/TcEnv.hs cleanly. Applied patch compiler/typecheck/TcEvidence.hs cleanly. Applied patch compiler/typecheck/TcInstDcls.hs cleanly. Applied patch compiler/typecheck/TcRnDriver.hs cleanly. Applied patch compiler/typecheck/TcRnMonad.hs cleanly. Applied patch compiler/typecheck/TcSplice.hs cleanly. Applied patch compiler/typecheck/TcTyClsDecls.hs cleanly. Applied patch compiler/typecheck/TcTypeNats.hs cleanly. Applied patch compiler/typecheck/TcValidity.hs cleanly. Applied patch compiler/types/CoAxiom.hs cleanly. Applied patch compiler/types/Coercion.hs cleanly. Applied patch compiler/types/FamInstEnv.hs cleanly. Applied patch compiler/types/Kind.hs cleanly. Applied patch compiler/types/OptCoercion.hs cleanly. Applied patch compiler/types/TyCon.hs cleanly. Applied patch compiler/types/TypeRep.hs cleanly. Applied patch compiler/types/TypeRep.hs-boot cleanly. Applied patch compiler/utils/Outputable.hs cleanly. Applied patch compiler/vectorise/Vectorise/Generic/PADict.hs cleanly. Applied patch compiler/vectorise/Vectorise/Generic/PAMethods.hs cleanly. Applied patch compiler/vectorise/Vectorise/Type/Env.hs cleanly. Applied patch compiler/vectorise/Vectorise/Utils/PADict.hs cleanly. Applied patch libraries/template-haskell/Language/Haskell/TH.hs cleanly. Applied patch libraries/template-haskell/Language/Haskell/TH/Lib.hs cleanly. Applied patch libraries/template-haskell/Language/Haskell/TH/Ppr.hs cleanly. Applied patch libraries/template-haskell/Language/Haskell/TH/PprLib.hs cleanly. Applied patch libraries/template-haskell/Language/Haskell/TH/Syntax.hs cleanly. Applied patch testsuite/tests/ghci/scripts/T6018ghci.script cleanly. Applied patch testsuite/tests/ghci/scripts/T6018ghci.stdout cleanly. Applied patch testsuite/tests/ghci/scripts/T6018ghcifail.script cleanly. Applied patch testsuite/tests/ghci/scripts/T6018ghcifail.stderr cleanly. Applied patch testsuite/tests/ghci/scripts/T6018ghcirnfail.script cleanly. Applied patch testsuite/tests/ghci/scripts/T6018ghcirnfail.stderr cleanly. Applied patch testsuite/tests/ghci/scripts/all.T cleanly. Applied patch testsuite/tests/rename/should_fail/T6018rnfail.hs cleanly. Applied patch testsuite/tests/rename/should_fail/T6018rnfail.stderr cleanly. Applied patch testsuite/tests/rename/should_fail/all.T cleanly. Applied patch testsuite/tests/typecheck/should_compile/T6018.hs cleanly. Applied patch testsuite/tests/typecheck/should_compile/T6018.hs-boot cleanly. Applied patch testsuite/tests/typecheck/should_compile/T6018.stderr cleanly. Applied patch testsuite/tests/typecheck/should_compile/T6018a.hs cleanly. Applied patch testsuite/tests/typecheck/should_compile/all.T cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018Afail.hs cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018Bfail.hs cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018Cfail.hs cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018Dfail.hs cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018fail.hs cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018fail.stderr cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed1.hs cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed1.stderr cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed2.hs cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed2.stderr cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed3.hs cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed3.stderr cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed4.hs cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed4.stderr cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed5.hs cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed5.stderr cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed6.hs cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed6.stderr cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed7.hs cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed7.stderr cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed8.hs cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed8.stderr cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed9.hs cleanly. Applied patch testsuite/tests/typecheck/should_fail/T6018failclosed9.stderr cleanly. Applied patch testsuite/tests/typecheck/should_fail/all.T cleanly. Applied patch utils/haddock cleanly. warning: 2 lines add whitespace errors. Submodule 'libffi-tarballs' () registered for path 'libffi-tarballs' Submodule 'libraries/Cabal' () registered for path 'libraries/Cabal' Submodule 'libraries/Win32' () registered for path 'libraries/Win32' Submodule 'libraries/array' () registered for path 'libraries/array' Submodule 'libraries/binary' () registered for path 'libraries/binary' Submodule 'libraries/bytestring' () registered for path 'libraries/bytestring' Submodule 'libraries/containers' () registered for path 'libraries/containers' Submodule 'libraries/deepseq' () registered for path 'libraries/deepseq' Submodule 'libraries/directory' () registered for path 'libraries/directory' Submodule 'libraries/dph' () registered for path 'libraries/dph' Submodule 'libraries/filepath' () registered for path 'libraries/filepath' Submodule 'libraries/haskeline' () registered for path 'libraries/haskeline' Submodule 'libraries/hoopl' () registered for path 'libraries/hoopl' Submodule 'libraries/hpc' () registered for path 'libraries/hpc' Submodule 'libraries/parallel' () registered for path 'libraries/parallel' Submodule 'libraries/pretty' () registered for path 'libraries/pretty' Submodule 'libraries/primitive' () registered for path 'libraries/primitive' Submodule 'libraries/process' () registered for path 'libraries/process' Submodule 'libraries/random' () registered for path 'libraries/random' Submodule 'libraries/stm' () registered for path 'libraries/stm' Submodule 'libraries/terminfo' () registered for path 'libraries/terminfo' Submodule 'libraries/time' () registered for path 'libraries/time' Submodule 'libraries/transformers' () registered for path 'libraries/transformers' Submodule 'libraries/unix' () registered for path 'libraries/unix' Submodule 'libraries/vector' () registered for path 'libraries/vector' Submodule 'libraries/xhtml' () registered for path 'libraries/xhtml' Submodule 'nofib' () registered for path 'nofib' Submodule 'utils/haddock' () registered for path 'utils/haddock' Submodule 'utils/hsc2hs' () registered for path 'utils/hsc2hs' Submodule path 'libraries/Cabal': checked out '82d2fe1f5083e56f0b2d2c2409a3f673a56a5fe4' Submodule path 'libraries/containers': checked out 'ddf4e4a7abbfb81161251437a6a5bbe8167a7cde' Submodule path 'libraries/directory': checked out 'bcb8c40b5e0a17030bcc085b46bf8718ea713107' Submodule path 'libraries/hoopl': checked out 'a90a3af92be400af8912555bce21b041a1c48ad4' Submodule path 'libraries/pretty': checked out '110b105c491387a73dd37b4f86a686ed131767b2' Submodule path 'libraries/random': checked out '180aa65507d5b7c63d9f438ff908774bafc88d0d' fatal: reference is not a tree: d809f9d656780273f4f79e7a9fb934f783f79702 Unable to checkout 'd809f9d656780273f4f79e7a9fb934f783f79702' in submodule path 'utils/haddock' OKAY Successfully committed patch. simonpj@cam-05-unx:~/code/HEAD-2$ git fetch git fetch simonpj@cam-05-unx:~/code/HEAD-2$ git submodule update git submodule update simonpj@cam-05-unx:~/code/HEAD-2$ git status git status # On branch arcpatch-D202 # Untracked files: # (use "git add <file>..." to include in what will be committed) # # flat-skol-diff # foo # foo2 # index.html.1 # index.html.2 # index.html.3 # resume # spj-patch # spj-patch-save # testsuite/mk/ghcconfig_home_simonmar_fp_bin_x86_64-unknown-linux_ghc.mk # testsuite/tests/simplCore/should_compile/T8538.hs # testsuite/tests/simplCore/should_compile/T9073.hs # tmp-patch # untch-patch nothing added to commit but untracked files present (use "git add" to track) simonpj@cam-05-unx:~/code/HEAD-2$

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How do I investigate parser conflicts?
by Jan Stolarek 22 Dec '14

22 Dec '14

I noticed that changes I made to the Parser on my branch increase the number of reduce/reduce conflicts. Are there any tools/techniques/etc I can use to investigate this? Or do I just have to use trial and error (possibly guided with some knowledge of parsing)? Specifically, is there any way I can check which productions are causing conflicts? Janek

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ANN: deepseq-bounded, seqaid, leaky
by Andrew Seniuk 21 Dec '14

21 Dec '14

This trio of related packages explores strictness control in a variety of ways. deepseq-bounded provides classes and generic functions to artificially force evaluation, to extents controlled by static or dynamic configuration. seqaid puts that into practise, providing a GHC plugin to auto-instrument your package with a strictness harness, which is dynamically optimisable during runtime. This is supported directly in the GHC compilation pipeline, without requiring (or performing!) any edits to your sources. leaky is a minimal, prototypic executable that leaks space under current state-of-the-art compilation (GHC 7.8.3 -O2, at the present time). deepseq-bounded hackage: https://hackage.haskell.org/package/deepseq-bounded homepage: http://www.fremissant.net/deepseq-bounded seqaid hackage: https://hackage.haskell.org/package/seqaid homepage: http://www.fremissant.net/seqaid leaky hackage: https://hackage.haskell.org/package/leaky homepage: http://www.fremissant.net/leaky Reddit discussion for the three together: http://www.reddit.com/r/haskell/comments/2ps8f5/ann_deepseqbounded_seqaid_l… Easiest way to try them all, is to install seqaid and run the demo: cabal install seqaid seqaid demo This tests seqaid on a local copy of the leaky source package. It turned out to be routine to extend deepseq-bounded and seqaid to dynamically configurable parallelisation (paraid?). Many other wrappers could be explored, too! Maybe seqaid should be renamed to koolaid or something... It's a pretty complicated system, and just first release, so there's bound to be lots of problems. I've not set up a bug tracker, but will maintain a casual list of bugs and feature requests at http://www.fremissant.net/seqaid/trac and will set up a proper tracker if there's interest. Any isssues (or comments), I'm here, or on the reddit discussion (or email). Andrew Seniuk rasfar on #haskell

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Perl for Windows and GHC
by Gintautas Miliauskas 21 Dec '14

21 Dec '14

Hi, apologies again about disappearing completely. I started a new job recently and have been flying all over the place. I'm happy to see that D339 (auto-download mingw, upgrade version of gcc) has been merged, but there is an issue that needs followup. Austin mentioned that we need a Perl distribution for a proper GHC runtime. This is not a problem while running in msys2, since msys provides a perl binary, but this makes packaging a self-sufficient GHC distribution harder, AFAIU. Can we punt on this and let the Haskell Platform folks figure out how to package Perl properly (that's the only context where it's necessary, right?), or is this an urgent issue? If the latter, should we roll back D339 until it's resolved? If we really need to package perl, the PortableZIP edition of Strawberry Perl <http://strawberryperl.com/releases.html> should work, I think. It's on the heavy side (92MB) and would probably need to be trimmed beforehand though. Are there any utilities other than ghc-split which rely on perl at ghc runtime? If not, are there any plans to convert ghc-split to a sane language? I would sign up if I knew I would have the time... :( -- Gintautas Miliauskas

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GHC Heap Profiler time axis
by Anton Dessiatov 19 Dec '14

19 Dec '14

Hello, GHC hackers! Reposting this message from haskell-café, because it seems like this mailing list is closer to the subject. For the last 2 days I’m debugging something that looks like a space leak. My program is a rather long-running network service. When I first used heap profiler I was a bit confused with its output that showed that my program was running for only about 0.3-0.4 seconds when I launched it idling for about a minute. That was confusing enough for me to dig into GHC sources trying to figure out the reason behind this and I found that values of the sample times are taken from the mut_user_time function, which returns a time that process spent in user-mode code (outside the kernel) minus time spent on garbage collection. This introduces great amount of unpredictable non-linearity of the heap profile graph x axis, which I personally consider very counterintuitive. So my question is does anybody know why is it done this way? Wouldn’t it be better if x axis would just show a time elapsed since the process started? Kind regards, Anton.

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