#6068: Panic in GHCi when using functional dependencies and promoted kinds -------------------------------------+------------------------------------ Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.5 Resolution: | Keywords: PolyKinds Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: GHCi crash | Difficulty: Unknown Test Case: polykinds/T6068 | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Changes (by nomeata): * cc: hvr (added) * status: closed => new * resolution: fixed => Comment: In a fresh checkout (95216e8fa0ecb98189dce29f0b89b3b0f8d439c6, `distclean`’ed and built), I get: {{{ =====> T6068(ghci) 2026 of 3814 [0, 0, 0] cd ./polykinds && HC='/home/jojo/build/haskell/ghc/inplace/bin/ghc-stage2' HC_OPTS='-dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db -rtsopts -fno-ghci-history ' '/home/jojo/build/haskell/ghc/inplace/bin /ghc-stage2' --interactive -v0 -ignore-dot-ghci -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db -rtsopts -fno-ghci-history <T6068.script >T6068.run.stdout 2>T6068.run.stderr Actual stderr output differs from expected: --- /dev/null 2013-11-12 10:20:30.826690103 +0100 +++ ./polykinds/T6068.run.stderr 2013-11-12 10:39:54.333361005 +0100 @@ -0,0 +1,9 @@ +ghc-stage2: panic! (the 'impossible' happened) + (GHC version 7.7.20131108 for x86_64-unknown-linux): + ASSERT failed! + file compiler/typecheck/TcMType.lhs line 809 + [D] _ :: mp{tv aEn} [tau[0]] + ghc-prim:GHC.Types.~{(w) tc 31Q} kp_aEi{tv} [tau[0]] (CIrredEvCan) + +Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug + Actual stdout output differs from expected: --- ./polykinds/T6068.stdout 2013-10-05 15:18:57.118579683 +0200 +++ ./polykinds/T6068.run.stdout 2013-11-12 10:39:54.193361010 +0100 @@ -1 +0,0 @@ -exists Nothing :: Floop a mp => Existential mp *** unexpected failure for T6068(ghci) }}} Strangely, on [https://s3.amazonaws.com/archive.travis- ci.org/jobs/13835382/log.txt travis] it succeeded. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6068#comment:3> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler