#15186: ghc 8.4.2 panic in profiling build -------------------------------------+------------------------------------- Reporter: kquick | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.4.2 Keywords: | Operating System: Linux Architecture: x86_64 | Type of failure: Compile-time (amd64) | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- When building our crucible-llvm library (https://github.com/GaloisInc/crucible) with profiling enabled, we encounter the following: {{{ [19 of 21] Compiling Lang.Crucible.LLVM.Translation ( src/Lang/Crucible/LLVM/Translation.hs, dist/build/Lang/Crucible/LLVM/Translation.p_o ) ghc: panic! (the 'impossible' happened) (GHC version 8.4.2 for x86_64-unknown-linux): isUnliftedType r_a4IqS :: TYPE rep_a4IqR Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1150:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:1939:10 in ghc:Type Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} Procedure to reproduce: {{{ $ git clone https://github.com/GaloisInc/crucible $ cd crucible/crucible-llvm $ ghc --version The Glorious Glasgow Haskell Compilation System, version 8.4.2 $ cabal --version cabal-install version 2.0.0.1 compiled using version 2.0.1.0 of the Cabal library $ cabal configure --enable-library-profiling $ cabal build }}} Note: the llvm-pretty dependency on Hackage is not compatible with GHC 8.4.2; use the latest from the github repo at http://github.com/elliottt /llvm-pretty. The crucible and what4 dependencies come from sibling subdirectories in the same crucible checkout. This builds successfully when using GHC 8.2.2 instead. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15186 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler