#7928: GHC fails to terminate while compiling with optimizations -----------------------------+---------------------------------------------- Reporter: Ptharien's Flame | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.6.3 | Keywords: Os: Unknown/Multiple | Architecture: x86_64 (amd64) Failure: Other | Blockedby: Blocking: | Related: -----------------------------+---------------------------------------------- When I try to compile random-fu-0.2.4.0 from Hackage, using the command: {{{ cabal install --ghc --ghc-options="-fllvm -O2 -dcore-lint" --enable- optimization=2 random-fu-0.2.4.0 }}} I get the following output: {{{ Resolving dependencies... Configuring random-fu-0.2.4.0... Building random-fu-0.2.4.0... Preprocessing library random-fu-0.2.4.0... [ 1 of 27] Compiling Data.Random.Internal.Find ( src/Data/Random/Internal/Find.hs, dist/build/Data/Random/Internal/Find.o ) [ 2 of 27] Compiling Data.Random.Internal.Fixed ( src/Data/Random/Internal/Fixed.hs, dist/build/Data/Random/Internal/Fixed.o ) [ 3 of 27] Compiling Data.Random.Internal.TH ( src/Data/Random/Internal/TH.hs, dist/build/Data/Random/Internal/TH.o ) [ 4 of 27] Compiling Data.Random.Lift ( src/Data/Random/Lift.hs, dist/build/Data/Random/Lift.o ) [ 5 of 27] Compiling Data.Random.RVar ( src/Data/Random/RVar.hs, dist/build/Data/Random/RVar.o ) [ 6 of 27] Compiling Data.Random.Distribution ( src/Data/Random/Distribution.hs, dist/build/Data/Random/Distribution.o ) [ 7 of 27] Compiling Data.Random.Distribution.Uniform ( src/Data/Random/Distribution/Uniform.hs, dist/build/Data/Random/Distribution/Uniform.o ) Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading package transformers-0.3.0.0 ... linking ... done. Loading package mtl-2.1.2 ... linking ... done. Loading package MonadPrompt-1.0.0.3 ... linking ... done. Loading package array-0.4.0.1 ... linking ... done. Loading package deepseq-1.3.0.1 ... linking ... done. Loading package containers-0.5.0.0 ... linking ... done. Loading package pretty-1.1.1.0 ... linking ... done. Loading package template-haskell ... linking ... done. Loading package syb-0.4.0 ... linking ... done. Loading package th-extras-0.0.0.2 ... linking ... done. Loading package flexible-defaults-0.0.1.1 ... linking ... done. Loading package old-locale-1.0.0.5 ... linking ... done. Loading package old-time-1.1.0.1 ... linking ... done. Loading package time-1.4.0.1 ... linking ... done. Loading package random-1.0.1.1 ... linking ... done. Loading package mersenne-random-pure64-0.2.0.3 ... linking ... done. Loading package primitive-0.5.0.1 ... linking ... done. Loading package vector-0.10.0.1 ... linking ... done. Loading package mwc-random-0.12.0.1 ... linking ... done. Loading package stm-2.4.2 ... linking ... done. Loading package stateref-0.3 ... linking ... done. Loading package random-source-0.3.0.4 ... linking ... done. Loading package rvar-0.2.0.1 ... linking ... done. Loading package MonadRandom-0.1.9 ... linking ... done. Loading package random-shuffle-0.0.4 ... linking ... done. Loading package monad-loops-0.4.2 ... linking ... done. Loading package continued-fractions-0.9.1.1 ... linking ... done. Loading package converge-0.1.0.1 ... linking ... done. Loading package gamma-0.9.0.2 ... linking ... done. Loading package erf-2.0.0.0 ... linking ... done. [ 8 of 27] Compiling Data.Random.List ( src/Data/Random/List.hs, dist/build/Data/Random/List.o ) [ 9 of 27] Compiling Data.Random.Distribution.Bernoulli ( src/Data/Random/Distribution/Bernoulli.hs, dist/build/Data/Random/Distribution/Bernoulli.o ) [10 of 27] Compiling Data.Random.Distribution.Categorical ( src/Data/Random/Distribution/Categorical.hs, dist/build/Data/Random/Distribution/Categorical.o ) *** Core Lint warnings : in result of Desugar (after optimization) *** <no location info>: Warning: [RHS of $c>>_aMYc :: forall p_aMMn. GHC.Num.Num p_aMMn => forall a_a3Jr b_a3Js. Data.Random.Distribution.Categorical.Categorical p_aMMn a_a3Jr -> Data.Random.Distribution.Categorical.Categorical p_aMMn b_a3Js -> Data.Random.Distribution.Categorical.Categorical p_aMMn b_a3Js] INLINE binder is (non-rule) loop breaker: $c>>_aMYc }}} It then freezes for an as-far-as-I-known indefinite amount of time; I have tried it several times, and it never moves beyond that. Once, I left it for two whole hours without any change. Every time, I have had to manually interrupt it with {{{ctrl-c}}}. On the other hand, if I instead use the command: {{{ cabal install --ghc --ghc-options="-fllvm -O1 -dcore-lint" --enable- optimization=1 random-fu-0.2.4.0 }}} It produces literally identitical output up to the point that the first command stopped at, but it continues as normal afterwards and finishes installing random-fu as expected. My terminal confirms that the {{{ghc}}} executable (as opposed to, say, {{{opt}}} or {{{llc}}}) is the one that the first command gets stuck on. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7928 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler