February 2014 - Glasgow-haskell-users

RFC: include a cabal-install executable in future GHC releases
by Carter Schonwald 04 May '14

04 May '14

Hey everyone, I'd like to propose that GHC releases 7.8.1 onwards include a cabal-install (aka cabal) executable, but not include the library deps of cabal-install that aren't already distributed with ghc.(unless ghc should have those deps baked in, which theres very very good reasons not to do.). currently if someone wants just a basic haskell install of the freshest ghc they have to install a ghc bindist, then do a boostrap build of cabal-install by hand (if they want to actually get anything done :) ). This is not a human friendly situation for folks who are new to haskell tooling, but want to try out haskell dev on a server style vm or the like! point being: It'd be great for haskell usability (and egads amounts of config time, even by seasoned users) the ghc bindists / installers included a cabal-install binary thoughts? -Carter

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RC1 build failures on Debian
by Joachim Breitner 04 Mar '14

04 Mar '14

Hi, with RC1 in experimental, the Debian auto-builders have now picked up building 7.8, and it is failing on armel, hurd-i386, mips and mipsel: armel (https://buildd.debian.org/status/fetch.php?pkg=ghc&arch=armel&ver=7.8.20140…) "inplace/bin/ghc-stage2" -o utils/haddock/dist/build/tmp/haddock -hisuf hi -osuf o -hcsuf hc -static -H32m -O -lffi -optl-pthread -optc-mlong-calls -hide-all-packages -i -iutils/haddock/driver -iutils/haddock/src -iutils/haddock/vendor/attoparsec-0.10.4.0 -iutils/haddock/dist/build -iutils/haddock/dist/build/autogen -Iutils/haddock/dist/build -Iutils/haddock/dist/build/autogen -optP-DIN_GHC_TREE -optP-include -optPutils/haddock/dist/build/autogen/cabal_macros.h -package Cabal-1.18.1.3 -package array-0.5.0.0 -package base-4.7.0.0 -package bytestring-0.10.4.0 -package containers-0.5.4.0 -package deepseq-1.3.0.2 -package directory-1.2.0.2 -package filepath-1.3.0.2 -package ghc-7.8.20140130 -package xhtml-3000.2.1 -funbox-strict-fields -Wall -fwarn-tabs -O2 -XHaskell2010 -no-user-package-db -rtsopts -odir utils/haddock/dist/build -hidir utils/haddock/dist/build -stubdir utils/haddock/dist/build utils/haddock/dist/build/Main.o utils/haddock/dist/build/Documentation/Haddock.o utils/haddock/dist/build/Data/Attoparsec.o utils/haddock/dist/build/Data/Attoparsec/ByteString.o utils/haddock/dist/build/Data/Attoparsec/ByteString/Char8.o utils/haddock/dist/build/Data/Attoparsec/Combinator.o utils/haddock/dist/build/Data/Attoparsec/Number.o utils/haddock/dist/build/Data/Attoparsec/ByteString/FastSet.o utils/haddock/dist/build/Data/Attoparsec/ByteString/Internal.o utils/haddock/dist/build/Data/Attoparsec/Internal.o utils/haddock/dist/build/Data/Attoparsec/Internal/Types.o utils/haddock/dist/build/Haddock.o utils/haddock/dist/build/Haddock/Interface.o utils/haddock/dist/build/Haddock/Interface/Rename.o utils/haddock/dist/build/Haddock/Interface/Create.o utils/haddock/dist/build/Haddock/Interface/AttachInstances.o utils/haddock/dist/build/Haddock/Interface/LexParseRn.o utils/haddock/dist/build/Haddock/Interface/ParseModuleHeader.o utils/haddock/dist/build/Haddock/Parser.o utils/haddock/dist/build/Haddock/Parser/Util.o utils/haddock/dist/build/Haddock/Utf8.o utils/haddock/dist/build/Haddock/Utils.o utils/haddock/dist/build/Haddock/Backends/Xhtml.o utils/haddock/dist/build/Haddock/Backends/Xhtml/Decl.o utils/haddock/dist/build/Haddock/Backends/Xhtml/DocMarkup.o utils/haddock/dist/build/Haddock/Backends/Xhtml/Layout.o utils/haddock/dist/build/Haddock/Backends/Xhtml/Names.o utils/haddock/dist/build/Haddock/Backends/Xhtml/Themes.o utils/haddock/dist/build/Haddock/Backends/Xhtml/Types.o utils/haddock/dist/build/Haddock/Backends/Xhtml/Utils.o utils/haddock/dist/build/Haddock/Backends/LaTeX.o utils/haddock/dist/build/Haddock/Backends/HaddockDB.o utils/haddock/dist/build/Haddock/Backends/Hoogle.o utils/haddock/dist/build/Haddock/ModuleTree.o utils/haddock/dist/build/Haddock/Types.o utils/haddock/dist/build/Haddock/Doc.o utils/haddock/dist/build/Haddock/Version.o utils/haddock/dist/build/Haddock/InterfaceFile.o utils/haddock/dist/build/Haddock/Options.o utils/haddock/dist/build/Haddock/GhcUtils.o utils/haddock/dist/build/Haddock/Convert.o utils/haddock/dist/build/Paths_haddock.o /«PKGBUILDDIR»/compiler/stage2/build/libHSghc-7.8.20140130.a(genSym.o): In function `genSym': genSym.c:(.text+0x84): undefined reference to `arm_atomic_spin_lock' genSym.c:(.text+0x88): undefined reference to `arm_atomic_spin_unlock' collect2: error: ld returned 1 exit status make[2]: *** [utils/haddock/dist/build/tmp/haddock] Error 1 make[1]: *** [all] Error 2 make[1]: Leaving directory `/«PKGBUILDDIR»' make: *** [build-stamp] Error 2 hurd (https://buildd.debian.org/status/fetch.php?pkg=ghc&arch=hurd-i386&ver=7.8.2…) "inplace/bin/ghc-stage1" -optc-Wall -optc-Wextra -optc-Wstrict-prototypes -optc-Wmissing-prototypes -optc-Wmissing-declarations -optc-Winline -optc-Waggregate-return -optc-Wpointer-arith -optc-Wmissing-noreturn -optc-Wnested-externs -optc-Wredundant-decls -optc-Iincludes -optc-Iincludes/dist -optc-Iincludes/dist-derivedconstants/header -optc-Iincludes/dist-ghcconstants/header -optc-Irts -optc-Irts/dist/build -optc-DCOMPILING_RTS -optc-fno-strict-aliasing -optc-fno-common -optc-O2 -optc-fomit-frame-pointer -optc-DDYNAMIC -optc-DRtsWay=\"rts_dyn\" -fPIC -dynamic -H32m -O -lffi -optl-pthread -Iincludes -Iincludes/dist -Iincludes/dist-derivedconstants/header -Iincludes/dist-ghcconstants/header -Irts -Irts/dist/build -DCOMPILING_RTS -package-name rts -dcmm-lint -i -irts -irts/dist/build -irts/dist/build/autogen -Irts/dist/build -Irts/dist/build/autogen -O2 -c rts/hooks/StackOverflow.c -o rts/dist/build/hooks/StackOverflow.dyn_o ghc-stage1: panic! (the 'impossible' happened) (GHC version 7.8.20140130 for i386-unknown-gnu): howToAccessLabel: PIC not defined for this platform Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug "inplace/bin/ghc-stage1" -optc-Wall -optc-Wextra -optc-Wstrict-prototypes -optc-Wmissing-prototypes -optc-Wmissing-declarations -optc-Winline -optc-Waggregate-return -optc-Wpointer-arith -optc-Wmissing-noreturn -optc-Wnested-externs -optc-Wredundant-decls -optc-Iincludes -optc-Iincludes/dist -optc-Iincludes/dist-derivedconstants/header -optc-Iincludes/dist-ghcconstants/header -optc-Irts -optc-Irts/dist/build -optc-DCOMPILING_RTS -optc-fno-strict-aliasing -optc-fno-common -optc-O2 -optc-fomit-frame-pointer -optc-DDYNAMIC -optc-DRtsWay=\"rts_dyn\" -fPIC -dynamic -H32m -O -lffi -optl-pthread -Iincludes -Iincludes/dist -Iincludes/dist-derivedconstants/header -Iincludes/dist-ghcconstants/header -Irts -Irts/dist/build -DCOMPILING_RTS -package-name rts -dcmm-lint -i -irts -irts/dist/build -irts/dist/build/autogen -Irts/dist/build -Irts/dist/build/autogen -O2 -c rts/sm/BlockAlloc.c -o rts/dist/build/sm/BlockAlloc.dyn_o make[2]: *** [rts/dist/build/Apply.dyn_o] Error 1 make[1]: *** [all] Error 2 make: *** [build-stamp] Error 2 dpkg-buildpackage: error: debian/rules build gave error exit status 2 mips (https://buildd.debian.org/status/fetch.php?pkg=ghc&arch=mips&ver=7.8.201401…) mipsel (https://buildd.debian.org/status/fetch.php?pkg=ghc&arch=mipsel&ver=7.8.2014…) In file included from rts/sm/Evac.c:21:0: rts/sm/GCTDecl.h:139:2: error: #error Cannot find a way to declare the thread-local gc variable! #error Cannot find a way to declare the thread-local gc variable! ^ make[2]: *** [rts/dist/build/.depend-v-p-dyn-l-debug-thr-thr_debug-thr_l-thr_p-debug_dyn-thr_dyn-thr_debug_dyn-l_dyn-thr_l_dyn-thr_debug_p.c_asm] Error 1 make[2]: *** Waiting for unfinished jobs.... echo "compiler_stage2_depfile_haskell_EXISTS = YES" >> compiler/stage2/build/.depend-v-p-dyn.haskell.tmp for dir in compiler/stage2/build/./ compiler/stage2/build/CodeGen/ compiler/stage2/build/CodeGen/Platform/ compiler/stage2/build/Hoopl/ compiler/stage2/build/Llvm/ compiler/stage2/build/LlvmCodeGen/ compiler/stage2/build/PPC/ compiler/stage2/build/RegAlloc/ compiler/stage2/build/RegAlloc/Graph/ compiler/stage2/build/RegAlloc/Linear/ compiler/stage2/build/RegAlloc/Linear/PPC/ compiler/stage2/build/RegAlloc/Linear/SPARC/ compiler/stage2/build/RegAlloc/Linear/X86/ compiler/stage2/build/RegAlloc/Linear/X86_64/ compiler/stage2/build/SPARC/ compiler/stage2/build/SPARC/CodeGen/ compiler/stage2/build/Vectorise/ compiler/stage2/build/Vectorise/Builtins/ compiler/stage2/build/Vectorise/Generic/ compiler/stage2/build/Vectorise/Monad/ compiler/stage2/build/Vectorise/Type/ compiler/stage2/build/Vectorise/Utils/ compiler/stage2/build/X86/; do if test ! -d $dir; then mkdir -p $dir; fi done grep -v ' : [a-zA-Z]:/' compiler/stage2/build/.depend-v-p-dyn.haskell.tmp > compiler/stage2/build/.depend-v-p-dyn.haskell.tmp2 sed '/hs$/ p ; /hs$/ s/o /hi /g ; /hs$/ s/:/ : %hi: %o / ; /hs$/ s/^/$(eval $(call hi-rule,/ ; /hs$/ s/$/))/ ; /hs-boot$/ p ; /hs-boot$/ s/o-boot /hi-boot /g ; /hs-boot$/ s/:/ : %hi-boot: %o-boot / ; /hs-boot$/ s/^/$(eval $(call hi-rule,/ ; /hs-boot$/ s/$/))/' compiler/stage2/build/.depend-v-p-dyn.haskell.tmp2 > compiler/stage2/build/.depend-v-p-dyn.haskell make[1]: *** [all] Error 2 make[1]: Leaving directory `/«PKGBUILDDIR»' make: *** [build-stamp] Error 2 dpkg-buildpackage: error: debian/rules build gave error exit status 2 Can anyone tell already from what the problem is, and preferably how to fix it? Greetings, Joachim -- Joachim “nomeata” Breitner mail(a)joachim-breitner.de • http://www.joachim-breitner.de/ Jabber: nomeata(a)joachim-breitner.de • GPG-Key: 0x4743206C Debian Developer: nomeata(a)debian.org

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OutsideIn(X) question
by Alejandro Serrano Mena 27 Feb '14

27 Feb '14

(Cross-posted from Haskell-Café) I don't know if this is the best forum to ask questions about the OutsideIn(X) paper that lies below type inference in GHC. Any way, I sent it to Haskell-café and was advised to send it here also. My question related about the proof of soundness and principality, specifically Lemma 7.2 (to be found in page 67). In that lemma, it's stated that QQ and \phi' Q_q ||- \phi Q_w <-> \phi' Q_w'. I'm trying to recover the proof (which is omitted in the text), but I stumble upon a wall when trying to work out what happens in the case an axiom is applied. In particular, I'm playing with an example where QQ (the set of axioms) = { forall. C a => D a } (where C and D are one-parameter type classes) Q_q = { } Q_w = { D Int } Thus, if I apply the rule DINSTW (to be found in page 65), I get a new Q_w' = { C Int } Now, if the lemma 7.2 is true, it should be the case that (1) QQ ||- C Int <-> D Int which in particular means that I have the two implications (2) { forall. C a => D a, C Int } ||- D Int (3) { forall. C a => D a, D Int } ||- C Int (2) follows easily by applying the AXIOM rule of ||- (as shown in page 54). However, I don't see how to make (3) work :( I think that understanding this example will be key for my understanding of the whole system. Anybody could point to the error in my reasoning or to places where I could find more information? Thanks in advance.

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haskell xml parsing for larger files?
by Christian Maeder 20 Feb '14

20 Feb '14

Hi, I've got some difficulties parsing "large" xml files (> 100MB). A plain SAX parser, as provided by hexpat, is fine. However, constructing a tree consumes too much memory on a 32bit machine. see http://trac.informatik.uni-bremen.de:8080/hets/ticket/1248 I suspect that sharing strings when constructing trees might greatly reduce memory requirements. What are suitable libraries for string pools? Before trying to implement something myself, I'ld like to ask who else has tried to process large xml files (and met similar memory problems)? I have not yet investigated xml-conduit and hxt for our purpose. (These look scary.) In fact, I've basically used the content trees from "The (simple) xml package" and switching to another tree type is no fun, in particular if this gains not much. Thanks Christian

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ANNOUNCE: GHC 7.8.1 Release Candidate 1
by Austin Seipp 20 Feb '14

20 Feb '14

We are pleased to announce the first release candidate for GHC 7.8.1: http://www.haskell.org/ghc/dist/7.8.1-rc1/ http://www.haskell.org/ghc/docs/7.8.1-rc1/html/ This includes the source tarball and bindists for Windows, Linux, OS X, FreeBSD, and Solaris, on x86 and x86_64. There is a signed copy of the SHA256 hashes available (attached) using my GPG key (keyid 0x3B58D86F). We plan to make the 7.8.1 RC2 release quite soon, as we're aware of some existing issues. Please test as much as possible; bugs are much cheaper if we find them before the release! -- Regards, Austin Seipp, Haskell Consultant Well-Typed LLP, http://www.well-typed.com/

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Re: haskell xml parsing for larger files?
by Chris Smith 20 Feb '14

20 Feb '14

Have you looked at tagsoup? On Feb 20, 2014 3:30 AM, "Christian Maeder" <Christian.Maeder(a)dfki.de> wrote: Hi, I've got some difficulties parsing "large" xml files (> 100MB). A plain SAX parser, as provided by hexpat, is fine. However, constructing a tree consumes too much memory on a 32bit machine. see http://trac.informatik.uni-bremen.de:8080/hets/ticket/1248 I suspect that sharing strings when constructing trees might greatly reduce memory requirements. What are suitable libraries for string pools? Before trying to implement something myself, I'ld like to ask who else has tried to process large xml files (and met similar memory problems)? I have not yet investigated xml-conduit and hxt for our purpose. (These look scary.) In fact, I've basically used the content trees from "The (simple) xml package" and switching to another tree type is no fun, in particular if this gains not much. Thanks Christian _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users(a)haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

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7.8.1, template haskell, and dynamic libraries
by harry 19 Feb '14

19 Feb '14

The docs for 7.8.1 say "Template Haskell must now load dynamic object files, not static ones". Does this mean that, if I'm using Template Haskell, every package which the templates depend on have to be built with --enable-shared? -- View this message in context: http://haskell.1045720.n5.nabble.com/7-8-1-template-haskell-and-dynamic-lib… Sent from the Haskell - Glasgow-haskell-users mailing list archive at Nabble.com.

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State of -XImpredicativeTypes
by Merijn Verstraaten 19 Feb '14

19 Feb '14

Lectori salutem, What is the actual state of ImpredicativeTypes? It appears documented as a "properly" finished GHC extension, but on IRC and other places I keep hearing it's poorly tested, buggy or incomplete. Is this true or just FUD? Cheers, Merijn

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Re: ghc-7.8.1 and stm
by Joachim Breitner 19 Feb '14

19 Feb '14

Hi David, Am Dienstag, den 18.02.2014, 14:12 -0800 schrieb David Fox: > It seems to me that the stm library that is supposed to be built into > ghc-7.8.1 is missing. The deb provides and conflicts with > libghc-stm-dev , but does not provide libghc-stm-dev-2.4.2.1-abcde. this seems to be the result of a possible inadvertent change in the GHC source tarball creation: stm had been a "extra" lib already in 7.6 and before, but was not part of the tarball. Herbert or Austin, is the sdist code not doing the right thing here? Greetings, Joachim -- Joachim "nomeata" Breitner Debian Developer nomeata(a)debian.org | ICQ# 74513189 | GPG-Keyid: 4743206C JID: nomeata(a)joachim-breitner.de | http://people.debian.org/~nomeata

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Re: 7.8.1-candidate fail
by Jan Stolarek 17 Feb '14

17 Feb '14

Thanks. I upgraded Squeeze to Wheezy recently just because of that issue, so it's kinda solved for me. Janek Dnia piątek, 14 lutego 2014, Tyler Huffman napisał: > I added a comment in the ticket, but it looks like Debian Squeeze is using > libgmp3-dev 2:4.3.2, which was the same version that I had when I was > running into this issue. > > Using an updated version of libgmp3-dev will fix the issue, but I'm not > entirely sure if we need to consider supporting the packages in Debian > Squeeze repository since Debian Wheezy is the new stable distribution, and > it uses libgmp-dev 2:5.0.5. Someone with more intimate knowledge of GHC > development might be able to speak on this issue. > > > Regards, > Tyler Huffman > > On Thu, Feb 6, 2014 at 1:50 PM, Jan Stolarek <jan.stolarek(a)p.lodz.pl> wrote: > > I had the same problem on Debian Squeeze: > > > > https://ghc.haskell.org/trac/ghc/ticket/8666 > > > > What is your distro? > > > > CCing ghc-devs. > > > > Janek > > > > Dnia czwartek, 6 lutego 2014, Sergei Meshveliani napisał: > > > Dear GHC team, > > > > > > I am trying to test ghc-7.8.20140130-src.tar.bz2 > > > > > > I make it from source with ghc-7.6.3 on Debian Linux (64 bit). > > > > > > ./configure looks all right. > > > > > > And `make' reports after 40 minutes: > > > > > > ------------------------------------------------------- > > > ... > > > ... > > > "inplace/bin/ghc-stage1" -optc-Ilibraries/integer-gmp/. > > > -optc-I'/home/mechvel/g..... > > > ... > > > ... > > > /usr/bin/ld: libraries/integer-gmp/gmp/objs/aors.o: relocation > > > R_X86_64_32 against `__gmpz_sub' can not be used when making a shared > > > object; recompile with -fPIC > > > libraries/integer-gmp/gmp/objs/aors.o: could not read symbols: Bad > > > value collect2: ld returned 1 exit status > > > make[1]: *** > > > [libraries/integer-gmp/dist-install/build/libHSinteger-gmp-0.5.1.0\ > > > -ghc7.8.20140130.so] Error 1 > > > ------------------------------------------------------- > > > > > > > > > What might this mean? Need I to install a fresher libgmp ? > > > > > > Thanks, > > > > > > ------ > > > Sergei > > > > > > _______________________________________________ > > > Glasgow-haskell-users mailing list > > > Glasgow-haskell-users(a)haskell.org > > > http://www.haskell.org/mailman/listinfo/glasgow-haskell-users > > > > _______________________________________________ > > ghc-devs mailing list > > ghc-devs(a)haskell.org > > http://www.haskell.org/mailman/listinfo/ghc-devs

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