April 2014 - ghc-tickets

[GHC] #8591: Concurrent executions of ghc-pkg can cause inconstant package.cache files
by GHC 14 Jun '15

14 Jun '15

#8591: Concurrent executions of ghc-pkg can cause inconstant package.cache files ------------------------------------+---------------------------- Reporter: janm | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Package system | Version: 7.6.3 Keywords: ghc-pkg race | Operating System: FreeBSD Architecture: Unknown/Multiple | Type of failure: Other Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+---------------------------- I am doing 24 way parallel builds of system images, including all packages on a system. This includes ghc and multiple ghc packages. I am seeing intermittent dependency failure from the ghc packaging system. From examining Main.hs in ghc-pkg, I see the function withFileAtomic write to a temporary file in package.conf.d and then atomically rename on top of a target file, package.cache in the case. With parallel execution the last rename would win, leading to lost entries in package.cache. In my case, the following things happened: ("Building" indicates a start, "Built" indicates completion, "Installing" is setup in a separate chroot'd environment and is isolated) The FreeBSD ports system is used to drive the Haskell build system. The process works single threaded and fails intermittently when done in parallel. Building: devel/hs-data-default-instances-base Building: devel/hs-data-default-instances-containers Building: devel/hs-data-default-instances-old-locale Built: devel/hs-dlist Building: devel/hs-data-default-instances-dlist Built: devel/hs-temporary Built: jail-image-full Installing: system-image__jail-image-full Built: devel/hs-base64-bytestring Built: archivers/hs-zlib Building: security/hs-digest Built: devel/hs-syb Building: textproc/hs-hs-bibutils Building: textproc/hs-pandoc-types Built: devel/hs-utf8-string Built: devel/hs-data-default-instances-old-locale Built: devel/hs-data-default-instances-containers Built: devel/hs-data-default-instances-base Built: devel/hs-data-default-instances-dlist Building: devel/hs-data-default Built: devel/hs-random Installed: system-image__lang/ghc Installing: system-image__archivers/hs-zlib Installing: system-image__devel/hs-utf8-string Installing: system-image__devel/hs-syb Installing: system-image__devel/hs-base64-bytestring Installing: system-image__devel/hs-data-default-class Installing: system-image__devel/hs-dlist Installing: system-image__devel/hs-random Installing: system-image__devel/hs-temporary Installing: system-image__devel/hs-extensible-exceptions Built: devel/hs-data-default FAILED The error from the Haskell data-default build was: setup: At least the following dependencies are missing: data-default-instances-base -any Looking in the in the package.conf.d directory shows that the data- default-instances-base-0.0.1-7bdf8678f0d8637e096e397e7910f82a.conf file was present, but running "ghc-pkg list" did not show data-default- instances-base Running /usr/local/lib/cabal/ghc-7.6.3/data-default-instances- base-0.0.1/register.sh (which was also present) caused ghc-pkg to now show data-default-instances-base. To me this looks like a race condition between multiple instances of ghc- pkg causing the cache to become inconsistent. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8591> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8435: Do not copy stack after stack overflow
by GHC 12 Jun '15

12 Jun '15

#8435: Do not copy stack after stack overflow ------------------------------+-------------------------------------------- Reporter: ezyang | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: Component: Runtime | Version: 7.7 System | Operating System: Unknown/Multiple Keywords: | Type of failure: Runtime performance bug Architecture: | Test Case: Unknown/Multiple | Blocking: Difficulty: Unknown | Blocked By: | Related Tickets: | ------------------------------+-------------------------------------------- I am not sure, but I was doing a close reading of `threadStackOverflow` and noticed that after we throw a stack overflow exception, we fall through to the code responsible for allocating a new stack and copying the code over. An old iteration of the stack overflow code (removed in the commit cited below) did return after throwing the exception, and I did not see anything in the commit message suggesting the change was intentional. It seems sound to copy the stack; it will just become dead immediately. The relevant commit: {{{ commit f30d527344db528618f64a25250a3be557d9f287 Author: Simon Marlow <marlowsd(a)gmail.com> Date: Wed Dec 15 12:08:43 2010 +0000 Implement stack chunks and separate TSO/STACK objects }}} Suggested (untested) patch: {{{ diff --git a/rts/Threads.c b/rts/Threads.c index 742119d..ccd6b17 100644 --- a/rts/Threads.c +++ b/rts/Threads.c @@ -533,6 +533,7 @@ threadStackOverflow (Capability *cap, StgTSO *tso) // Send this thread the StackOverflow exception throwToSingleThreaded(cap, tso, (StgClosure *)stackOverflow_closure); + return; } }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8435> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8172: Expose CWD and import search paths in GHCi via new `:show paths` command
by GHC 11 Jun '15

11 Jun '15

#8172: Expose CWD and import search paths in GHCi via new `:show paths` command -------------------------------------------+------------------------------- Reporter: hvr | Owner: hvr Type: feature request | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.7 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Easy (less than 1 hour) | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: -------------------------------------------+------------------------------- - Currently, GHCi provides a `:cd` command but no respective builtin command to query the currently set path. - Moreover, there's no obvious way to query the currently active `importPaths` dynamic flags field, to find out which `-i` options are currently in effect. The attached patch extends `:show` with a `:show paths` subcommand, printing the CWD and the current value of `importPaths`: {{{ Ok, modules loaded: Main, InteractiveUI, Paths_ghci_ng, GhciMonad, GhciTags. λ> :show paths current working directory: /home/hvr/Haskell/My/ghci-ng module import search paths: dist/build/ghci-ng/ghci-ng-tmp ghc dist/build/autogen λ> :set -i λ> :show paths current working directory: /home/hvr/Haskell/My/ghci-ng module import search paths: none > :cd /tmp Warning: changing directory causes all loaded modules to be unloaded, because the search path has changed. > :show paths current working directory: /tmp module import search paths: none }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8172> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8244: Removing the Cabal dependency
by GHC 06 Jun '15

06 Jun '15

#8244: Removing the Cabal dependency ------------------------------------+------------------------------------- Reporter: nh2 | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- GHC depends on cabal, which is so far has been problematic many times, for many reasons. A few discussions include: * http://www.haskell.org/pipermail/haskell-cafe/2013-September/108746.html * http://www.haskell.org/pipermail/ghc-devs/2013-March/000821.html GHC uses only a very small part of Cabal, in these files: {{{ ./compiler/ghci/Linker.lhs ./compiler/main/Packages.lhs ./compiler/main/PackageConfig.hs ./compiler/main/Finder.lhs }}} plus 1 file for ghc-pkg: ./utils/ghc-pkg/Main.hs (see http://www.haskell.org/pipermail/haskell-cafe/2013-September/108750.html for details). It was proposed that either * the package format could be a plain specification without direct code dependencies * the Cabal package could be split off into Cabal-the-build-system and a minimal part to describe the package DB to be shared by Cabal and GHC The Cabal part that is used is in only a few modules of Distribution.* while the remaining majority of the Cabal-the-library package is not used (e.g. none of Distribution.Simple.*). Decoupling GHC and Cabal seems to be a public desire, yet there are some problems with these approaches. Let us discuss them in this ticket. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8244> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8723: sdist should not have to build everything
by GHC 04 Jun '15

04 Jun '15

#8723: sdist should not have to build everything ----------------------------------------------+---------------------------- Reporter: nomeata | Owner: Type: task | Status: new Priority: low | Milestone: Component: Build System | Version: 7.6.3 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Moderate (less than a day) | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: ----------------------------------------------+---------------------------- It would be nice if instead of {{{ $ perl boot $ ./configure $ make $ make sdist }}} it would suffice to run {{{ $ perl boot $ ./configure $ make sdist }}} and if that would not build more than necessary to generate the tarballs. It would save time on the GHC-HEAD-Debian-Package-autobuilder that I am currently working on. I might look into this bug eventually, but if someone else feels like doing it: Even better. (Difficulty estimated conservatively; might well be less than an hour, besides maybe waiting for test runs to finish :-)) Remember to update MakingReleases and Building/StandardTargets if this is implemented. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8723> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8292: linker_unload test doesn't work on Windows
by GHC 31 May '15

31 May '15

#8292: linker_unload test doesn't work on Windows ------------------------------------+---------------------------------- Reporter: ezyang | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: Component: Test Suite | Version: 7.7 Keywords: | Operating System: Windows Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: linker_unload Blocked By: | Blocking: Related Tickets: | ------------------------------------+---------------------------------- I fixed up the major issues but I am getting: {{{ "/c/Users/ezyang/Dev/ghc-dyn/inplace/bin/ghc-stage2.exe" -fforce-recomp -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db -rtsopts -c Test.hs -v0 # -rtsopts causes a warning "/c/Users/ezyang/Dev/ghc-dyn/inplace/bin/ghc-stage2.exe" -fforce-recomp -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db linker_unload.c -o linker_unload -no-hs-main -optc-Werror ./linker_unload \Users\ezyang\Dev\ghc-dyn\libraries\base\dist- install\build/libHSbase-4.7.0.0.a \Users\ezyang\Dev\ghc-dyn\libraries\ghc-prim\dist-install\build/libHSghc- prim-0.3.1.0.a \Users \ezyang\Dev\ghc-dyn\libraries\integer-gmp\dist-install\build/libHSinteger- gmp-0.5.1.0.a linker_unload.exe: \Users\ezyang\Dev\ghc-dyn\libraries\base\dist- install\build/libHSbase-4.7.0. 0.a: unknown symbol `_select' }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8292> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8122: make binary-dist broken on OS X in HEAD
by GHC 26 May '15

26 May '15

#8122: make binary-dist broken on OS X in HEAD --------------------------------+------------------------------------------ Reporter: danharaj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Build System | Version: 7.7 Keywords: | Operating System: MacOS X Architecture: x86_64 | Type of failure: Installing GHC failed (amd64) | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | --------------------------------+------------------------------------------ After a successful configure and make, make binary-dist fails: {{{ ➜ ghc git:(master) make ===--- building phase 0 make -r --no-print-directory -f ghc.mk phase=0 phase_0_builds make[1]: Nothing to be done for `phase_0_builds'. ===--- building phase 1 make -r --no-print-directory -f ghc.mk phase=1 phase_1_builds make[1]: Nothing to be done for `phase_1_builds'. ===--- building final phase make -r --no-print-directory -f ghc.mk phase=final all make[1]: Nothing to be done for `all'. ➜ ghc git:(master) make binary-dist rm -f bindist-list make -r --no-print-directory -f ghc.mk bindist BINDIST=YES "cp" -p ghc/stage1/build/tmp/ inplace/lib/bin/ghc-stage1 cp: ghc/stage1/build/tmp/ is a directory (not copied). make[1]: *** [inplace/lib/bin/ghc-stage1] Error 1 make: *** [binary-dist-prep] Error 2 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8122> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8549: GHCI incorrectly link symbols defined with foreign import ccall
by GHC 23 May '15

23 May '15

#8549: GHCI incorrectly link symbols defined with foreign import ccall -------------------------+------------------------------------------------- Reporter: | Owner: qnikst | Status: new Type: bug | Milestone: Priority: | Version: 7.6.3 normal | Operating System: Unknown/Multiple Component: GHCi | Type of failure: GHCi crash Keywords: | Test Case: Architecture: | https://gist.github.com/qnikst/324a66914b3aba878be5 Unknown/Multiple | Blocking: Difficulty: | Unknown | Blocked By: | Related Tickets: | -------------------------+------------------------------------------------- I have a problem that ghci when loads modules that uses external symbols incorrectly links them, the problem is not reproducible if I'm compiling executable or load modules with :load command. As a result every Pointer value is equivalent to constant 0x0000fffffff225ff. A minimal example is in attached link, it contains a small package and description how to reproduce a bug. Problem is also reproduces on the ghc-HEAD. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8549> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8555: Simplify given `Coercible` constraints
by GHC 19 May '15

19 May '15

#8555: Simplify given `Coercible` constraints -------------------------------------+------------------------------------- Reporter: nomeata | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 7.7 checker) | Operating System: Unknown/Multiple Keywords: | Type of failure: GHC rejects Architecture: Unknown/Multiple | valid program Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #8503 | -------------------------------------+------------------------------------- It would be feasible and possibly useful if {{{ foo :: Coercible [a] [b] => a -> b foo = coerce }}} would work. This involve simplifying `CtGiven`s similar to how given (nominal) equalities are simplified. I’ll defer working on this, as it is not strictly required, it seems. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8555> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8799: Orientation of given `Coercible` constraints
by GHC 19 May '15

19 May '15

#8799: Orientation of given `Coercible` constraints -------------------------------------------+------------------------------- Reporter: nomeata | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler (Type checker) | Version: 7.6.3 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: #8555 | Test Case: | Blocking: -------------------------------------------+------------------------------- {{{ Prelude> :m + GHC.Exts Prelude GHC.Exts> let f :: Coercible a b => b -> a ; f = coerce <interactive>:3:40: Could not coerce from ‛b’ to ‛a’ because ‛b’ and ‛a’ are different types. arising from a use of ‛coerce’ from the context (Coercible a b) bound by the type signature for f :: Coercible a b => b -> a at <interactive>:3:10-32 In the expression: coerce In an equation for ‛f’: f = coerce }}} Something better could be done here (but its not clear what exactly, and to what general extend). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8799> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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