June 2016 - ghc-tickets

[GHC] #10458: GHCi fails to load shared object (the 'impossible' happened)
by GHC 11 Oct '16

11 Oct '16

#10458: GHCi fails to load shared object (the 'impossible' happened) -----------------------------------------+--------------------------------- Reporter: rleslie | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.10.1 Keywords: | Operating System: Linux Architecture: x86_64 (amd64) | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -----------------------------------------+--------------------------------- I have a project that uses two external libraries, namely `-lcrypt` and `-lpcre`. Building with `cabal` and running the resulting executable works as expected, but I'm having trouble starting a REPL in GHCi: {{{ % cabal repl Preprocessing executable 'etamoo' for EtaMOO-0.2.1.0... GHCi, version 7.10.1: http://www.haskell.org/ghc/ :? for help /usr/bin/ld: dist/build/etamoo/etamoo-tmp/src/cbits/crypt.o: relocation R_X86_64_PC32 against undefined symbol `crypt' can not be used when making a shared object; recompile with -fPIC /usr/bin/ld: final link failed: Bad value collect2: error: ld returned 1 exit status }}} The error suggests I need `-fPIC`, and this seems to help the `-lcrypt` case, but now I get: {{{ % cabal repl --ghc-options="-fPIC" Preprocessing executable 'etamoo' for EtaMOO-0.2.1.0... GHCi, version 7.10.1: http://www.haskell.org/ghc/ :? for help ghc: panic! (the 'impossible' happened) (GHC version 7.10.1 for x86_64-unknown-linux): Loading temp shared object failed: /tmp/ghc21539_0/libghc21539_2.so: undefined symbol: pcre_callout Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} FYI the C type of `pcre_callout` is a little unusual: {{{ extern int (*pcre_callout)(pcre_callout_block *); }}} In other words it is a global variable (pointer to function), not a function itself. Any advice is welcome, including the proper way to start GHCi given these external dependencies, as well as on this apparent bug. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10458> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9877: ForeignImport coercion evaluated before typechecking
by GHC 10 Oct '16

10 Oct '16

#9877: ForeignImport coercion evaluated before typechecking -------------------------------------+------------------------------------- Reporter: varosi | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Keywords: | Operating System: Windows Architecture: x86_64 (amd64) | Type of failure: Compile- Difficulty: Unknown | time crash Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Under Windows 8.1 x64 with Haskell Platform 2014.02 and EclipseFP I got: buildwrapper.exe: panic! (the 'impossible' happened) (GHC version 7.8.3 for x86_64-unknown-mingw32): ForeignImport coercion evaluated before typechecking on the first line of file that has: {{{ #!div style="font-size: 80%" Code highlighting: {{{#!haskell {-# LANGUAGE ForeignFunctionInterface, RankNTypes, OverloadedStrings, ScopedTypeVariables #-} module Persist( persistWrite, persistRead ) where import System.Win32.Types import Graphics.Win32.GDI.Types import Foreign.C.String import Foreign.Marshal.Array import Control.Exception foreign import ccall unsafe "SHGetFolderPathW" cSHGetFolderPathW :: HWND -> INT -> HANDLE -> DWORD -> CWString -> IO LONG }}} }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9877> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10881: internal error: evacuate: strange closure type 5101248
by GHC 10 Oct '16

10 Oct '16

#10881: internal error: evacuate: strange closure type 5101248 -------------------------------------+------------------------------------- Reporter: burbly | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: Component: Runtime | Version: 7.10.2 System | Keywords: strange | Operating System: Windows closure type 5101248 | Architecture: x86_64 | Type of failure: Runtime crash (amd64) | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- Running a compiled executable on some complex input is causing this: postparse.exe: internal error: evacuate: strange closure type 5101248 (GHC version 7.10.2 for x86_64_unknown_mingw32) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Running under Cygwin on Windows 8.1, 64. I suspect this may be a memory-related issue, but it's hard to diagnose as postparse.exe is operating in a larger ecosystem. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10881> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11153: building lens-4.12.3 impossible happened: dupe _hs_primitive_memcpy
by GHC 10 Oct '16

10 Oct '16

#11153: building lens-4.12.3 impossible happened: dupe _hs_primitive_memcpy -----------------------------------------+--------------------------------- Reporter: blippy | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: libraries (other) | Version: 7.10.2 Keywords: | Operating System: Windows Architecture: x86 | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -----------------------------------------+--------------------------------- I issued the command: stack install lens hoping to upgrade to lens-4.13 and I received the following error log: GHC runtime linker: fatal error: I found a duplicate definition for symbol _hsprimitive_memcpy whilst processing object file C:\apps\HaskellPlatform\7.10.2-a\lib\extralibs\primitive-0.6\HSprimitive-0.6-3d4UsQu7pJCEtlsxN3gLjk.o This could be caused by: * Loading two different object files which export the same symbol * Specifying the same object file twice on the GHCi command line * An incorrect `package.conf' entry, causing some object to be loaded twice. ghc: panic! (the 'impossible' happened) (GHC version 7.10.2 for i386-unknown-mingw32): loadObj "C:\\apps\\HaskellPlatform\\7.10.2-a\\lib\\extralibs\\primitive-0.6\\HSprimitive-0.6-3d4UsQu7pJCEtlsxN3gLjk.o": failed Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11153> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12171: cygwin - option to accept ISO C99... unsupported
by GHC 10 Oct '16

10 Oct '16

#12171: cygwin - option to accept ISO C99... unsupported -------------------------------------+------------------------------------- Reporter: wozgonon | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Build System | Version: 8.0.1 Keywords: | Operating System: Windows Architecture: x86 | Type of failure: Building GHC | failed Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Tried to build Haskell under cygwin under Windows 10 (x86_64) but /configure failed. I had a look on google and through the bug tracker but could not find anything helpful. Note that in the output from ./configure check two versions of gcc.exe 1) ... /ghc/inplace/mingw/bin/gcc.exe 2) C:/Program Files/Haskell Platform/8.0.1/lib/../mingw/bin/gcc.exe The check for the first succeeds but that for the second fails yet they both seem to be the same version of gcc.exe: (realgcc.exe (Rev3, Built by MSYS2 project) 5.2.0) {{{ checking for C:/unix/cygwin64/home/jb/haskell/ghc/inplace/mingw/bin/gcc.exe option to accept ISO C99... none needed checking for C:/Program Files/Haskell Platform/8.0.1/lib/../mingw/bin/gcc.exe option to accept ISO C99... unsupported }}} {{{ $ C:/unix/cygwin64/home/jb/haskell/ghc/inplace/mingw/bin/gcc.exe --version realgcc.exe (Rev3, Built by MSYS2 project) 5.2.0 Copyright (C) 2015 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. jb@fabulord ~/haskell/ghc $ "C:/Program Files/Haskell Platform/8.0.1/lib/../mingw/bin/gcc.exe" --version realgcc.exe (Rev3, Built by MSYS2 project) 5.2.0 Copyright (C) 2015 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12171> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11591: thread blocked indefinitely in an MVar operation
by GHC 10 Oct '16

10 Oct '16

#11591: thread blocked indefinitely in an MVar operation --------------------------------------+------------------------------- Reporter: PaulNibin | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 Keywords: | Operating System: Windows Architecture: x86_64 (amd64) | Type of failure: GHCi crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: --------------------------------------+------------------------------- *Main> take 24 [13,26..] [13,26,39,52,65,78,91,104,117,130,143,156,169,182,195,208,221,234,247,260,273,286,299,312] *Main> cycle [1,2,3] [1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2, *Main> *Main> *Main> *Main> take 10 (cycle [1,2,3]) [1,2,3,1,2,3,1,2,3,1] *Main> take 10 (cycle "Hel) ghc.exe: panic! (the 'impossible' happened) (GHC version 7.10.3 for x86_64-unknown-mingw32): thread blocked indefinitely in an MVar operation Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11591> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12206: No exposed API to get full text of ErrMsg
by GHC 09 Oct '16

09 Oct '16

#12206: No exposed API to get full text of ErrMsg -------------------------------------+------------------------------------- Reporter: bit | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHC API | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- In GHC version 7.10.3 it was possible to get the full text of an error message by using the functions `ErrUtils.errMsgShortDoc` and `ErrUtils.errMsgExtraInfo`. But in GHC version 8.0.1 the code has changed. The full text of the error message is stored in the `ErrMsg` field `ErrUtils.errMsgDoc`, but this field is hidden, and there doesn't seem to be any API to access its contents. The only workaround I can find is to use `ErrUtils.pprLocErrMsg`, and then strip out the first line containing the location info, and then manually unindent the 4-space "hang". This is quite ugly. I suggest exporting `ErrUtils.errMsgDoc`, and then for that to be useful the fields of `ErrUtils.ErrDoc` will also be needed. Additionally, `ErrUtils.formatErrDoc` could be a nice bonus to have (and if exported would lessen the need for the `ErrDoc` fields). The GHC API changes on every GHC release, so since backwards compatibility is not an issue, it would seem that there is no need to have a carefully exposed API, and there is no danger in liberally exporting stuff that clients could potentially find useful. Thank you -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12206> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11970: Simplify Parent
by GHC 09 Oct '16

09 Oct '16

#11970: Simplify Parent -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- This commit {{{ commit 96621b1b4979f449e873513e9de8d806257c9493 Associate pattern synonyms with types in module exports }}} added `PatternSynonym` to `RdrName.Parent`. That's a pretty heavy hammer. It forces us to add `IsPatSyn` to `AvailInfo`, including binary serialisation etc. And I think it's needed in precisely one place, namely `RnNames.findPatSyns`. Right? The caller of `findPatSyns` and the associated `lookupChildren` is jolly obscure and I don't fully understand it. I **think** the issue is this: * I want to allow an export item `T( K )`, where `K` is a pattern synonym, even though it's not really (yet) associated with `T`. I think the goal of this code was to reject the `K` if it's a data constructor. But we also have a **further** check in `tcExports` to check that `K` has the right type. Surely it'd be better to nuke this `PatternSynonym` and `IsPatSyn` stuff? Just use`isDataOcc` in the export lookup part. Then the `tcExport` check will object if you write an export item like `Either( Just )`. Fewer moving parts! Matthew, does this make sense? Might you look at it? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11970> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9547: Empty constraint tuples are mis-kinded
by GHC 07 Oct '16

07 Oct '16

#9547: Empty constraint tuples are mis-kinded -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Consider {{{ -- If :: forall k. 'Bool -> k -> k -> k type family If cond tru fls where If True tru fls = tru If False tru fls = fls foo :: If True () (Eq a) => a -> a foo = error "urk" }}} This should work fine. But we get {{{ Foo.hs:8:21: The third argument of `If' should have kind `*', but `Eq a' has kind `Constraint' In the type signature for `foo': foo :: If True () (Eq a) => a -> a }}} Reason: GHC is treating the `()` unit tuple as of kind `*`. Reason is that in the `HsTupleTy` case of `tc_hs_type` in `TcHsType`, we see {{{ -- In the [] case, it's not clear what the kind is, so guess * }}} And that guess is plain wrong in this case. Unfortunately I don't see an easy fix, but it's plain wrong as-is. Simon -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9547> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12130: ghc: panic! (the 'impossible' happened): find_tycon Block []
by GHC 06 Oct '16

06 Oct '16

#12130: ghc: panic! (the 'impossible' happened): find_tycon Block [] -------------------------------------+------------------------------------- Reporter: jeiea | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Template | Version: 8.0.1 Haskell | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I just tried building yesod-simple template project with nightly-2016-05-29 snapshot and some extra-deps package, and it seems to fail due to {{{$(widgetFile ...)}}} yesod template haskell clause. It was same on linux and windows, and when I remove handler ghc fails at Application module (and seems also due to template haskell). {{{ ~/yt> stack build ... yt-0.0.0: configure Configuring yt-0.0.0... yt-0.0.0: build Preprocessing library yt-0.0.0... [1 of 9] Compiling Settings ( Settings.hs, .stack- work/dist/x86_64-linux/Cabal-1.24.0.0/build/Settings.o ) [2 of 9] Compiling Settings.StaticFiles ( Settings/StaticFiles.hs, .stack- work/dist/x86_64-linux/Cabal-1.24.0.0/build/Settings/StaticFiles.o ) [3 of 9] Compiling Import.NoFoundation ( Import/NoFoundation.hs, .stack- work/dist/x86_64-linux/Cabal-1.24.0.0/build/Import/NoFoundation.o ) [4 of 9] Compiling Foundation ( Foundation.hs, .stack- work/dist/x86_64-linux/Cabal-1.24.0.0/build/Foundation.o ) [5 of 9] Compiling Import ( Import.hs, .stack- work/dist/x86_64-linux/Cabal-1.24.0.0/build/Import.o ) [6 of 9] Compiling Handler.Common ( Handler/Common.hs, .stack- work/dist/x86_64-linux/Cabal-1.24.0.0/build/Handler/Common.o ) [7 of 9] Compiling Handler.Home ( Handler/Home.hs, .stack- work/dist/x86_64-linux/Cabal-1.24.0.0/build/Handler/Home.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.1 for x86_64-unknown-linux): find_tycon Block [] Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Completed 179 action(s). -- While building package yt-0.0.0 using: /home/jeiea/.stack/setup-exe-cache/x86_64-linux/setup-Simple- Cabal-1.24.0.0-ghc-8.0.1 --builddir=.stack- work/dist/x86_64-linux/Cabal-1.24.0.0 build lib:yt exe:yt --ghc-options " -ddump-hi -ddump-to-file" Process exited with code: ExitFailure 1 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12130> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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