October 2015 - ghc-tickets

[GHC] #10860: The test `setnumcapabilities001` sometimes fails on Phabricator
by GHC 13 Oct '16

13 Oct '16

#10860: The test `setnumcapabilities001` sometimes fails on Phabricator -------------------------------------+------------------------------------- Reporter: thomie | Owner: simonmar Type: bug | Status: new Priority: high | Milestone: 7.12.1 Component: Runtime | Version: 7.10.2 System | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- {{{ setnumcapabilities001: internal error: ASSERTION FAILED: file rts/Schedule.c, line 406 }}} https://phabricator.haskell.org/harbormaster/build/5890/ Here it just timed out: https://phabricator.haskell.org/harbormaster/build/5904/?l=0 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10860> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[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] #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] #10163: Export typeRepKinds in Data.Typeable
by GHC 04 Oct '16

04 Oct '16

#10163: Export typeRepKinds in Data.Typeable -------------------------------------+------------------------------------- Reporter: | Owner: RyanGlScott | Status: new Type: feature | Milestone: request | Version: 7.10.1-rc3 Priority: normal | Operating System: Unknown/Multiple Component: | Type of failure: Other libraries/base | Blocked By: Keywords: | Related Tickets: Architecture: | Unknown/Multiple | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Now that {{{TypeRep}}} has a {{{[KindRep]}}} field internally, {{{Data.Typeable}}} should export {{{typeRepKinds}}} (alongside {{{typeRepTyCon}}} and {{{typeRepArgs}}}, which are currently exported) to allow users to access it. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10163> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8870: GHC 7.8.0 RC2 fails when compiling a hello world program on Windows 7 32bits
by GHC 02 Oct '16

02 Oct '16

#8870: GHC 7.8.0 RC2 fails when compiling a hello world program on Windows 7 32bits ----------------------------+--------------------------------------- Reporter: facundoq | Owner: Type: bug | Status: new Priority: highest | Milestone: Component: Compiler | Version: 7.8.1-rc2 Keywords: | Operating System: Windows Architecture: x86 | Type of failure: Compile-time crash Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------+--------------------------------------- Windows shows a window that says "GHC has stopped working" when compiling a simple hello world. Steps to reproduce 1) Download GHC 7.8 RC2 (http://www.haskell.org/ghc/dist/7.8.1-rc2/ghc-7.8.0.20140228-i386 -unknown-mingw32.tar.bz2) 2) Extract the contents of the tar to folder $GHC$ 3) Add $GHC$\bin and $GHC$\mingw\bin folder to the PATH, add env var "LANG=C". 4) Create file test.hs with contents: main = putStrLn "Hello, World!" 5) run "ghc test.hs". Interestingly, the error is not deterministic, ie, after running the command several times the program gets compiled. When that happens, and ff the file test.o is not deleted, further attempts to compile run succesfully. GHCi appears to work normally (when doing simple tests). More details: http://stackoverflow.com/questions/22291739/cant-install-packages-with- cabal-using-ghc-7-8rc2-and-windows-7 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8870> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10740: Ensure that ticky, profiler, and GC allocation numbers agree
by GHC 30 Sep '16

30 Sep '16

#10740: Ensure that ticky, profiler, and GC allocation numbers agree -------------------------------------+------------------------------------- Reporter: bgamari | Owner: bgamari Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- Currently we have several subsystems independently tracking allocations. It is very likely there are discrepancies between them. Ensuring that they agree would be a great way to test each of them (especially ticky, which is almost certainly bitrotted, see #10739). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10740> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9520: Running an action twice uses much more memory than running it once
by GHC 29 Sep '16

29 Sep '16

#9520: Running an action twice uses much more memory than running it once -------------------------------------+------------------------------------- Reporter: snoyberg | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Keywords: | Operating System: Linux Architecture: x86_64 (amd64) | Type of failure: Runtime Difficulty: Unknown | performance bug Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- This started as a [http://www.haskell.org/pipermail/haskell- cafe/2014-August/115751.html Haskell cafe discussion] about conduit. This may be related to #7206, but I can't be certain. It's possible that GHC is not doing anything wrong here, but I can't see a way that the code in question is misbehaving to trigger this memory usage. Consider the following code, which depends on conduit-1.1.7 and conduit- extra: {{{#!hs import Data.Conduit ( Sink, (=$), ($$), await ) import qualified Data.Conduit.Binary as CB import System.IO (withBinaryFile, IOMode (ReadMode)) main :: IO () main = do action "random.gz" --action "random.gz" action :: FilePath -> IO () action filePath = withBinaryFile filePath ReadMode $ \h -> do _ <- CB.sourceHandle h $$ CB.lines =$ sink2 1 return () sink2 :: (Monad m) => Int -> Sink a m Int sink2 state = do maybeToken <- await case maybeToken of Nothing -> return state Just _ -> sink2 $! state + 1 }}} The code should open up the file "random.gz" (I simply `gzip`ed about 10MB of data from /dev/urandom), break it into chunks at each newline character, and then count the number of lines. When I run it as-is, it uses 53KB of memory, which seems reasonable. However, if I uncomment the second call to `action` in `main`, maximum residency shoots up to 45MB (this seems to be linear in the size of the input file. I additionally tried copying `random.gz` into two files, `random1.gz` and `random2.gz`, and changed the two calls to `action` to use different file names. It still resulted in large memory usage. I'm going to continue working to make this a smaller reproducing test case, but I wanted to start with what I had so far. I'll also attach the core generated by both the low-memory and high-memory versions. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9520> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9349: excessive inlining with -fpre-inlining
by GHC 29 Sep '16

29 Sep '16

#9349: excessive inlining with -fpre-inlining --------------------------------------------+------------------------------ Reporter: rwbarton | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Keywords: | Differential: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime performance bug | Unknown/Multiple Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: --------------------------------------------+------------------------------ The program at https://gist.github.com/jorendorff/a3005968adc8f054baf7 runs very slowly when compiled with `-O` or higher. It seems that `arr` and/or `rangeMap` is being inlined into the do block on lines 89-91 and recomputed for each iteration of the loop. The program runs nearly instantly when compiled with `-O0` or with `-O -fno-pre-inlining`. (Of course, this does not mean `-fpre-inlining` is necessary the culprit; it could be enabling some subsequent misoptimization.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9349> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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