August 2014 - ghc-tickets

[GHC] #8046: Make the timer management scale better across multicore
by GHC 21 Nov '14

21 Nov '14

#8046: Make the timer management scale better across multicore ------------------------------------+------------------------------------- Reporter: tibbe | 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: | ------------------------------------+------------------------------------- A recent commit {{{ commit e843e73690f828498f6e33bb89f47a50c3ab2ac9 Author: Ian Lynagh <ian(a)well-typed.com> Date: Sat Jun 8 20:19:59 2013 +0100 IO manager: Edit the timeout queue directly, rather than using an edit list Fixes #7653. }}} undid an optimization to the management of timeouts (to fix a bug, which is good). We should check how much this hurt performance, but it might be better to rewrite the timeout management altogether. The current scheme scales poorly to several cores. We should probably have one priority queue per core and use an efficient mutable data structure. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8046> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8054: Undefined symbol during linking
by GHC 21 Nov '14

21 Nov '14

#8054: Undefined symbol during linking ------------------------------------+------------------------------------- Reporter: case | 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: | ------------------------------------+------------------------------------- On OSX, using GHC 7.6.3 and the package recursion-schemes 3.0.0.2, the following code causes the compiler to emit an error about undefined symbols. Code: {{{ import Data.Functor.Foldable x = project 1 :: Integer main = x `seq` return () }}} Error: {{{ λ ~/ ghc test.hs Linking test ... Undefined symbols for architecture x86_64: "_Main_x_closure", referenced from: _Main_main_info in test.o _Main_main_srt in test.o ld: symbol(s) not found for architecture x86_64 collect2: ld returned 1 exit status }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8054> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8056: Make Install fails on HEAD
by GHC 21 Nov '14

21 Nov '14

#8056: Make Install fails on HEAD ------------------------------------+------------------------------------- Reporter: fryguybob | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Build System | Version: 7.7 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- I'm trying to build the `perf` flavor of head and I'm getting an error with `make install`. The `quick` flavor works as expected. {{{ $ uname -a Linux ... 3.6.5-1.fc17.x86_64 ... $ ghc --version The Glorious Glasgow Haskell Compilation System, version 7.6.3 $ cabal --version cabal-install version 1.16.0.2 using version 1.16.0.3 of the Cabal library $ gcc --version gcc (GCC) 4.7.2 20120921 (Red Hat 4.7.2-2) ... $ git clone http://darcs.haskell.org/ghc.git/ ghc-7.8/ ... $ cd ghc-7.8 $ ./sync-all --testsuite get ... $ cp mk/build.mk.sample mk/build.mk $ vi mk/build.mk $ diff mk/build.mk mk/build.mk.sample 12c12 < BuildFlavour = perf --- > #BuildFlavour = perf $ perl boot ... $ ./configure --prefix=/localdisk/ryates/ghc-7.8-build/ ... $ make -j8 ... $ make install ... Installing library in /localdisk/ryates/ghc-7.8-build/lib/ghc-7.7.20130711/haskell2010-1.1.1.0 "/localdisk/ryates/ghc-7.8-build/lib/ghc-7.7.20130711/bin/ghc-pkg" --force --global-package-db "/localdisk/ryates/ghc-7.8-build/lib/ghc-7.7.20130711/package.conf.d" update rts/dist/package.conf.install /localdisk/ryates/ghc-7.8-build/lib/ghc-7.7.20130711/bin/ghc-pkg: symbol lookup error: /localdisk/ryates/ghc-7.8-build/lib/ghc-7.7.20130711/bin /ghc-pkg: undefined symbol: base_DataziList_intercalatezuzdspolyzugo_info make[1]: *** [install_packages] Error 127 make: *** [install] Error 2 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8056> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9293: GHCI :unset -XLanguageExtension returns "don't know how to reverse -XLanguageExtension"
by GHC 21 Nov '14

21 Nov '14

#9293: GHCI :unset -XLanguageExtension returns "don't know how to reverse -XLanguageExtension" -------------------------+------------------------------------------------- Reporter: | Owner: jfeltz | Status: new Type: bug | Milestone: Priority: | Version: 7.8.2 normal | Operating System: Unknown/Multiple Component: GHCi | Type of failure: None/Unknown Keywords: | Test Case: :set -XCPP followed by Architecture: x86 | :unset -XCPP Difficulty: | Blocking: Unknown | Blocked By: | Related Tickets: | -------------------------+------------------------------------------------- Any language extension tried appears to not work with :unset. To make matters worse, :unset expands to a number of options, misleading the user into thinking that it should (if that is the case). I eventually had to ask someone on IRC #haskell, leading to the :set -XNoLanguageExtension trick to do what I needed. A fix to :unset is suggested, or removing the misleading/non-working command. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9293> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8568: internal error: allocation of ... bytes too large
by GHC 21 Nov '14

21 Nov '14

#8568: internal error: allocation of ... bytes too large ------------------------------------+------------------------------------- Reporter: mojojojo | 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: | ------------------------------------+------------------------------------- Running the following GHCi session: {{{ import GHC.DataSize import qualified Data.HashTable.IO as HT import Control.Monad t <- HT.new :: IO (HT.BasicHashTable Int Char) forM_ [0..100000] $ \i -> HT.insert t i 'a' recursiveSize t }}} results in the following error: {{{ <interactive>: internal error: allocation of 1208480 bytes too large (GHC should have complained at compile-time) (GHC version 7.6.3 for x86_64_apple_darwin) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Abort trap: 6 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8568> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8149: GHC should warn about redundant import of a type name also if one of its record selectors is imported
by GHC 21 Nov '14

21 Nov '14

#8149: GHC should warn about redundant import of a type name also if one of its record selectors is imported ------------------------------------+------------------------------------- Reporter: Lemming | 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: | ------------------------------------+------------------------------------- Sorry, I have another corner case for a redundant import warning: {{{ module Main where import Control.Monad.Trans.Writer (WriterT, runWriterT) main :: IO () main = undefined runWriterT }}} This module will not provoke a warning, although the import of WriterT can be omitted. I assume this is because runWriterT is a record selector of WriterT and could (or should?) be imported as: {{{ import Control.Monad.Trans.Writer (WriterT(runWriterT)) }}} Since I used runWriterT like a regular function I did not care about its record selector feature. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8149> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9222: Unexpected DataKind Panic
by GHC 21 Nov '14

21 Nov '14

#9222: Unexpected DataKind Panic -------------------------------------------+------------------------------- Reporter: ekmett | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type checker) | 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: -------------------------------------------+------------------------------- Here's a simplified version of a panic I'm getting: {{{ {-# LANGUAGE RankNTypes, GADTs, DataKinds, PolyKinds, TypeOperators, TypeFamilies #-} import Data.Proxy data Want :: (i,j) -> * where Want :: (a ~ '(b,c) => Proxy b) -> Want a }}} {{{ GHCi, version 7.8.2: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. ghc: panic! (the 'impossible' happened) (GHC version 7.8.2 for x86_64-apple-darwin): tcTyVarDetails k{tv aAv} [tv] Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9222> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9368: Add strictly accumulating scanl' to Data.List
by GHC 20 Nov '14

20 Nov '14

#9368: Add strictly accumulating scanl' to Data.List -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: libraries/base | Version: 7.8.3 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Easy (less than 1 | Type of failure: hour) | None/Unknown Blocked By: | Test Case: Related Tickets: #9345 | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Joachim Breitner wrote a strictly accumulating fusable `scanl'` in a comment on #9345, and demonstrated that it can produce spectacularly good code. Therefore, it seems like a good thing to have in Data.List. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9368> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8094: Intermittent segfault when using ghc-7.6.3 -e on OSX 10.6.8
by GHC 20 Nov '14

20 Nov '14

#8094: Intermittent segfault when using ghc-7.6.3 -e on OSX 10.6.8 ----------------------------------+---------------------------------- Reporter: rampion | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: MacOS X Architecture: x86_64 (amd64) | Type of failure: Runtime crash Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+---------------------------------- This error was observed using the 64-bit version of ghc-7.6.3 packaged with the Haskell Platform 2013.2.0.0 for OSX. Running commands with `ghc -e` sometimes produces a segfault. {{{ % ghc -e 'return ()' ; echo $? 0 % ghc -e 'return ()' ; echo $? zsh: segmentation fault ghc -e 'return ()' 139 }}} I don't know exactly what's causing it, but I'm suspicious of the binary distributed with the package. When I pull it up in `gdb`, there are warnings pertaining to missing object files expected to be in a `/Users/ian` directory. There's never been an `ian` user on my machine, so I suspect that's an artifact from whomever built the binary. This may also be the root of the intermittent segfault {{{ % cd /Library/Frameworks/GHC.framework/Versions/7.6.3-x86_64/usr/lib/ghc-7.6.3 % gdb ghc GNU gdb 6.3.50-20050815 (Apple version gdb-1518) (Sat Feb 12 02:52:12 UTC 2011) Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "x86_64-apple-darwin"...Reading symbols for shared libraries .... done warning: Could not find object file "/Users/ian/zz64/ghc-7.6.3/rts/dist/build/libHSrts_thr.a(darwin64.o)" - no debug information available for "/var/folders/9z/yntzqjqn1j95xbpb6dr3qbww0000gn/T//ccr2b8iU.s". warning: Could not find object file "/Users/ian/zz64/ghc-7.6.3/rts/dist/build/libHSrts_thr.a(ffi64.o)" - no debug information available for "../src/x86/ffi64.c". warning: Could not find object file "/Users/ian/zz64/ghc-7.6.3/rts/dist/build/libHSrts_thr.a(prep_cif.o)" - no debug information available for "../src/prep_cif.c". warning: Could not find object file "/Users/ian/zz64/ghc-7.6.3/rts/dist/build/libHSrts_thr.a(types.o)" - no debug information available for "../src/types.c". (gdb) run -B. -e 'return ()' Starting program: /Library/Frameworks/GHC.framework/Versions/7.6.3-x86_64/usr/lib/ghc-7.6.3/ghc -B. -e 'return ()' Reading symbols for shared libraries + done Program exited normally. (gdb) run -B. -e 'return ()' Starting program: /Library/Frameworks/GHC.framework/Versions/7.6.3-x86_64/usr/lib/ghc-7.6.3/ghc -B. -e 'return ()' Reading symbols for shared libraries + done Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: KERN_INVALID_ADDRESS at address: 0x00000000f34ed440 0x00000001f34d659a in evacuate1 () (gdb) where #0 0x00000001f34d659a in evacuate1 () #1 0x00000001f34dc1b8 in scavenge_block1 () Previous frame inner to this frame (gdb could not unwind past this frame) (gdb) kill Kill the program being debugged? (y or n) y error while killing target (killing anyway): assertion failure on line 300 of "/SourceCache/gdb/gdb-1518/src/gdb/macosx/macosx-nat-inferior-util.c" in function "macosx_inferior_suspend_ptrace": status.value.sig == TARGET_SIGNAL_STOP warning: error on line 2182 of "/SourceCache/gdb/gdb-1518/src/gdb/macosx /macosx-nat-inferior.c" in function "macosx_kill_inferior_safe": (os/kern) failure (0x5x) (gdb) run -B. -e '()' Starting program: /Library/Frameworks/GHC.framework/Versions/7.6.3-x86_64/usr/lib/ghc-7.6.3/ghc -B. -e '()' Reading symbols for shared libraries + done () Program exited normally. (gdb) run -B. -e '()' Starting program: /Library/Frameworks/GHC.framework/Versions/7.6.3-x86_64/usr/lib/ghc-7.6.3/ghc -B. -e '()' Reading symbols for shared libraries + done Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: KERN_INVALID_ADDRESS at address: 0x00000000d1916440 [Switching to process 18462 thread 0x2003] 0x00000001d191bc44 in stg_ap_v_fast () (gdb) where #0 0x00000001d191bc44 in stg_ap_v_fast () #1 0x0000000000000000 in ?? () (gdb) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8094> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8068: ghc incorrectly accepts the Kannada TTHA character at the beginning of an identifier.
by GHC 20 Nov '14

20 Nov '14

#8068: ghc incorrectly accepts the Kannada TTHA character at the beginning of an identifier. ------------------------------------+------------------------------------- Reporter: malcolmw | 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: | ------------------------------------+------------------------------------- The code at http://hub.darcs.net/lelf/acme- lookofdisapproval/browse/Acme/LookOfDisapproval.lhs is accepted by ghc, but technically, the leading letter of the funny identifier (Kannada TTHA) is neither lowercase, uppercase, nor titlecase. It can be accepted in any position of an identifier except the first, where Haskell requires the character to be either upper/title-case (conid) or lower (varid). isLetter x && not (isUpper x) does not imply isLower(x). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8068> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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