May 2013 - ghc-tickets

[GHC] #7905: Type checker barfs on nonsensical expression
by GHC 11 May '13

11 May '13

#7905: Type checker barfs on nonsensical expression -------------------------------+-------------------------------------------- Reporter: jpaugh | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.6.2 | Keywords: Os: Linux | Architecture: x86 Failure: Compile-time crash | Blockedby: Blocking: | Related: -------------------------------+-------------------------------------------- I got the infamous "impossible bug" by trying something nonsensical in my program. I reproduced the bug in the attached minimal program (18 lines). The precise error message is: {{{ Impossible.hs:18:5: Couldn't match kind `* -> *' with `*' Expected type: [Char] -> ZT IO () Actual type: [Char] -> ZT IO () Kind incompatibility when matching types: [Char] :: * -> * [Char] :: * The function `lift'ghc: panic! (the 'impossible' happened) (GHC version 7.6.2 for i386-unknown-linux): kindFunResult ghc-prim:GHC.Prim.*{(w) tc 34d} }}} Note that this error occurs whether on not the ''MonadTrans'' instance is there. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7905> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7726: unexpected out of memory error on FreeBSD
by GHC 11 May '13

11 May '13

#7726: unexpected out of memory error on FreeBSD -------------------------------+-------------------------------------------- Reporter: nejstastnejsistene | Owner: Type: bug | Status: new Priority: normal | Component: Runtime System Version: 7.4.2 | Keywords: Os: FreeBSD | Architecture: x86 Failure: Runtime crash | Blockedby: Blocking: | Related: -------------------------------+-------------------------------------------- I wrote a daemon that periodically scrapes information from a webpage that crashes after about 20 hours with the error: "out of memory (requested 1048576 bytes)". The program runs fine on my Ubuntu machine, but always crashes on FreeBSD even though there is plenty of memory to spare/memory stays constant/etc. I boiled it down to the following code, which consistently crashes after about 4000-6000 iterations when compiled with -O2, and about 35000 without. {{{ import Data.Conduit import Data.Conduit.List import qualified Data.ByteString as B import Network.HTTP.Conduit main :: IO () main = do manager <- newManager def loop manager 1 loop :: Manager -> Int -> IO () loop manager i = do putStrLn $ show i request <- parseUrl "http://localhost:8000/courselist.html" html <- runResourceT $ do response <- http request manager fmap B.concat $ responseBody response $$+- consume loop manager $ i + 1 }}} For debugging, I served a copy of of a typical html sample from localhost using "python -m SimpleHTTPServer". The html file is attached. Sample Output:[[BR]] {{{ ... 35361 35362 35363 35364 35365 main: out of memory (requested 1048576 bytes) }}} Other information: {{{ $ uname -a FreeBSD oriskova 9.1-RELEASE FreeBSD 9.1-RELEASE #0 r243826: Tue Dec 4 06:55:39 UTC 2012 root@obrian.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC i386 }}} {{{ $ gcc -v Using built-in specs. Target: i386-undermydesk-freebsd Configured with: FreeBSD/i386 system compiler Thread model: posix[[BR]] gcc version 4.2.1 20070831 patched [FreeBSD] }}} I wasn't sure if I should submit this or not since it seemed fairly specific to http-conduit, but the wiki said to go ahead and submit runtime errors, so that's what I did. This is my first time ever submitting a bug report and I tried my best to follow all the instructions at [http://hackage.haskell.org/trac/ghc/wiki/ReportABug] but please tell me if there is something I'm doing wrong. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7726> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7889: Build Error (master branch)
by GHC 11 May '13

11 May '13

#7889: Build Error (master branch) -----------------------------+---------------------------------------------- Reporter: cg31 | Owner: Type: bug | Status: new Priority: normal | Component: libraries (other) Version: 7.6.3 | Keywords: gmp Os: Unknown/Multiple | Architecture: x86 Failure: None/Unknown | Blockedby: Blocking: | Related: -----------------------------+---------------------------------------------- I got this error while building the master branch. System is Windows 8 64-bit. Code grabbed from github. --------------------------------------------------- Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... ghc-stage2.exe: panic! (the 'impossible' happened) (GHC version 7.7.20130504 for i386-unknown-mingw32): loadArchive "z:\\Lang\\Haskell\\ghc_files\\git\\libraries \\integer-gmp\\dist-install\\build\\libHSinteger-gmp-0.5.1.0.a": failed Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug ghc-stage2.exe: Unknown PEi386 section name `.drectve' (while processing: z:\Lang\Haskell\ghc_files\git\libraries\integer-gmp\dist-install\build \libHSinteger-gmp-0.5.1.0.a) make[1]: *** [libraries/vector/dist- install/build/Data/Vector/Fusion/Stream/Monadic.o] Error 1 make: *** [all] Error 2 -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7889> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7887: panic when playing with pipes
by GHC 11 May '13

11 May '13

#7887: panic when playing with pipes -----------------------------+---------------------------------------------- Reporter: bfr | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.6.3 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Blockedby: Blocking: | Related: -----------------------------+---------------------------------------------- I am playing around with pipes-3.2.0 using ghc-6.7.3. I load this code in ghci: """ import Control.Proxy fork :: (Monad m, Proxy p1, Proxy p2, Proxy p3) => () -> Consumer p1 a (Producer p2 a (Producer p3 a m)) r fork () = runIdentityP . hoist (runIdentityP . hoist runIdentityP) $ forever $ do a <- request () -- Request from the 'Consumer' lift $ respond a -- Send to the outer 'Producer' lift $ lift $ respond a -- Send to the inner 'Producer' test :: (Proxy p) => () -> Producer p Int IO r test () = runIdentityP $ forever $ do respond 1 """ then I type *Main> :t hoist (hoist lift) $ test <interactive>:1:1: Warning: Could not deduce (Monad ()) arising from a use of `hoist' from the context (Monad m, MonadTrans t1, Proxy p, MFunctor t) bound by the inferred type of it :: (Monad m, MonadTrans t1, Proxy p, MFunctor t) => t (t1 m) -> Producer p Int IO r at Top level Possible fix: add an instance declaration for (Monad ()) In the expression: hoist (hoist lift) In the expression: hoist (hoist lift) $ test <interactive>:1:1: Warning: Could not deduce (MFunctor (->)) arising from a use of `hoist' from the context (Monad m, MonadTrans t1, Proxy p, MFunctor t) bound by the inferred type of it :: (Monad m, MonadTrans t1, Proxy p, MFunctor t) => t (t1 m) -> Producer p Int IO r at Top level Possible fix: add an instance declaration for (MFunctor (->)) In the expression: hoist (hoist lift) In the expression: hoist (hoist lift) $ test <interactive>:1:8: Warning:ghc: panic! (the 'impossible' happened) (GHC version 7.6.3 for x86_64-unknown-linux): kindFunResult <<details unavailable>> Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7887> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7871: 7.6.3 failed to build with make -j12
by GHC 10 May '13

10 May '13

#7871: 7.6.3 failed to build with make -j12 --------------------------------+------------------------------------------- Reporter: nwf | Owner: Type: bug | Status: new Priority: normal | Component: Build System Version: 7.6.3 | Keywords: Os: Linux | Architecture: x86_64 (amd64) Failure: Building GHC failed | Blockedby: Blocking: | Related: --------------------------------+------------------------------------------- This looks to be a missing dependency in the build system: {{{ HC [stage 1] compiler/stage2/build/TcSplice.o-boot HC [stage 1] compiler/stage2/build/CodeOutput.o HC [stage 1] compiler/stage2/build/RnHsDoc.o HC [stage 1] compiler/stage2/build/RnExpr.o-boot HC [stage 1] compiler/stage2/build/TcExpr.o-boot HC [stage 1] compiler/stage2/build/TcUnify.o-boot HC [stage 1] compiler/stage2/build/TcMatches.o-boot HC [stage 1] compiler/stage2/build/FloatIn.o HC [stage 1] libraries/bin-package-db/dist-install/build/libHSbin- package-db-0.0.0.0-ghc7.6.3.so Warning: -rtsopts and -with-rtsopts have no effect with -shared. Call hs_init_ghc() from your main() function to set these options. HC [stage 1] libraries/Cabal/Cabal/dist- install/build/Distribution/Simple/Haddock.p_o HC [stage 1] compiler/stage2/build/Rules.p_o HC [stage 1] compiler/stage2/build/HsExpr.p_o /usr/bin/ld: cannot find -lHSbin-package-db-0.0.0.0-ghc7.6.3 collect2: ld returned 1 exit status make[1]: *** [compiler/stage2/build/libHSghc-7.6.3-ghc7.6.3.so] Error 1 make[1]: *** Waiting for unfinished jobs.... "rm" -f libraries/haskeline/dist- install/build/libHShaskeline-0.7.0.2.a.contents "rm" -f libraries/haskeline/dist- install/build/libHShaskeline-0.7.0.2_p.a.contents "rm" -f libraries/Cabal/Cabal/dist- install/build/libHSCabal-1.16.0.a.contents make: *** [all] Error 2 }}} Re-running make without a -j option after this failure completes successfully. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7871> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #3977: Support double-byte encodings (Chinese/Japanese/Korean) on Windows
by GHC 10 May '13

10 May '13

#3977: Support double-byte encodings (Chinese/Japanese/Korean) on Windows ---------------------------------+------------------------------------------ Reporter: shelarcy | Owner: batterseapower Type: feature request | Status: new Priority: low | Milestone: 7.8.1 Component: libraries/base | Version: 6.13 Keywords: | Os: Windows Architecture: Unknown/Multiple | Failure: Incorrect result at runtime Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: #5754 | ---------------------------------+------------------------------------------ Changes (by igloo): * difficulty: => Unknown * milestone: 7.6.2 => 7.8.1 Comment: Is this now fixed in HEAD by this?: {{{ commit f982978eaa5d74c5dffe71c14a1555587b6a5e48 Author: Max Bolingbroke <batterseapower(a)hotmail.com> Date: Thu Apr 18 21:29:08 2013 +0100 Support for Windows DBCS and new SBCS with MultiByteToWideChar }}} -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3977#comment:17> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7855: Use optimizer for more information about incomplete pattern matches
by GHC 10 May '13

10 May '13

#7855: Use optimizer for more information about incomplete pattern matches -----------------------------+---------------------------------------------- Reporter: ezyang | Owner: Type: feature request | Status: new Priority: normal | Component: Compiler (Type checker) Version: 7.7 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Blockedby: Blocking: | Related: -----------------------------+---------------------------------------------- This mail gave me an idea that was too cute not to write down (though I don't expect it to be implemented any time soon), http://www.haskell.org/pipermail/haskell-cafe/2013-April/107775.html The observation is that the typechecking phase is not necessarily the best point in time to check for pattern coverage exhaustiveness: if we tentatively stub in a default case with an error, and after optimization passes, we find that this case has been eliminated, then in fact there was no pattern coverage incompleteness. So, the strategy would be to defer reporting certain coverage failures until we can do actually check if there are any problems later. Obviously if no predicates or view patterns (or similar things) are involved, then there is no point in attempting to defer it, but otherwise this could help reduce warnings in code that make heavy use of these features. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7855> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #5361: regSpill: out of spill slots!
by GHC 10 May '13

10 May '13

#5361: regSpill: out of spill slots! -----------------------------------------------------+---------------------- Reporter: markwright | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Compiler | Version: 7.1 Resolution: | Keywords: regSpill panic impossible Os: Linux | Architecture: x86_64 (amd64) Failure: Compile-time crash | Difficulty: Unknown Testcase: http://hackage.haskell.org/package/SHA | Blockedby: Blocking: | Related: -----------------------------------------------------+---------------------- Changes (by igloo): * priority: highest => high * milestone: 7.2.1 => 7.8.1 -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5361#comment:7> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #5361: regSpill: out of spill slots!
by GHC 10 May '13

10 May '13

#5361: regSpill: out of spill slots! -----------------------------------------------------+---------------------- Reporter: markwright | Owner: Type: bug | Status: new Priority: highest | Milestone: 7.2.1 Component: Compiler | Version: 7.1 Resolution: | Keywords: regSpill panic impossible Os: Linux | Architecture: x86_64 (amd64) Failure: Compile-time crash | Difficulty: Unknown Testcase: http://hackage.haskell.org/package/SHA | Blockedby: Blocking: | Related: -----------------------------------------------------+---------------------- Changes (by igloo): * owner: igloo => * status: closed => new * resolution: fixed => -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5361#comment:6> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #5361: regSpill: out of spill slots!
by GHC 10 May '13

10 May '13

#5361: regSpill: out of spill slots! -----------------------------------------------------+---------------------- Reporter: markwright | Owner: igloo Type: bug | Status: closed Priority: highest | Milestone: 7.2.1 Component: Compiler | Version: 7.1 Resolution: fixed | Keywords: regSpill panic impossible Os: Linux | Architecture: x86_64 (amd64) Failure: Compile-time crash | Difficulty: Unknown Testcase: http://hackage.haskell.org/package/SHA | Blockedby: Blocking: | Related: -----------------------------------------------------+---------------------- Changes (by igloo): * difficulty: => Unknown Old description: > runghc ./Setup.hs build > Building SHA-1.5.0.0... > Preprocessing library SHA-1.5.0.0... > [1 of 1] Compiling Data.Digest.Pure.SHA ( Data/Digest/Pure/SHA.hs, > dist/build/Data/Digest/Pure/SHA.o ) > ghc: panic! (the 'impossible' happened) > (GHC version 7.2.0.20110728 for x86_64-unknown-linux): > regSpill: out of spill slots! > regs to spill = 2479 > slots left = 2040 > > Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug New description: {{{ runghc ./Setup.hs build Building SHA-1.5.0.0... Preprocessing library SHA-1.5.0.0... [1 of 1] Compiling Data.Digest.Pure.SHA ( Data/Digest/Pure/SHA.hs, dist/build/Data/Digest/Pure/SHA.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.2.0.20110728 for x86_64-unknown-linux): regSpill: out of spill slots! regs to spill = 2479 slots left = 2040 Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5361#comment:5> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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