#10616: Panic in ghci debugger with PolyKinds and PhantomTypes -----------------------------------------+------------------------------- Reporter: bjmprice | 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: GHCi crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -----------------------------------------+------------------------------- The code {{{#!hs {-# LANGUAGE PolyKinds #-} data D a = A | B f d@A = const True d f B = False }}} when loaded in ghci, runs fine without breakpoints, but panics when breaking on {{{f A}}}, thus: {{{ *Main> f A True *Main> :break 5 Breakpoint 0 activated at DebuggerCrash.hs:5:9-20 *Main> f A ghc-stage2: panic! (the 'impossible' happened) (GHC version 7.10.1 for x86_64-unknown-linux): ASSERT failed! file compiler/typecheck/TcUnify.hs line 1138 k_amp }}} It is fine in 7.4.1 and 7.8.1. It panics in 7.10.1 and HEAD@d71b65f53a1daa2631d2c818c7ea6add77813532 Without one (or both) of PolyKinds or the phantom type it runs fine. {{{uname -a: Linux cam-05-unx 3.5.0-54-generic #81~precise1-Ubuntu SMP Tue Jul 15 04:02:22 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux}}} {{{ gcc -v: Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.6/lto-wrapper Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.6.3-1ubuntu5' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program- suffix=-4.6 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable- libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable- objc-gc --disable-werror --with-arch-32=i686 --with-tune=generic --enable- checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) }}} With {{{ghci-7.10.1 -v}}} {{{ ghci-7.10.1 -v ./DebuggerCrash.hs GHCi, version 7.10.1: http://www.haskell.org/ghc/ :? for help Glasgow Haskell Compiler, Version 7.10.1, stage 2 booted by GHC version 7.8.2 Using binary package database: /5playpen/t-bepric/ghc-7.10.1-build/inplace/lib/package.conf.d/package.cache wired-in package ghc-prim mapped to ghc-prim-0.4.0.0-inplace wired-in package integer-gmp mapped to integer-gmp-1.0.0.0-inplace wired-in package base mapped to base-4.8.0.0-inplace wired-in package rts mapped to builtin_rts wired-in package template-haskell mapped to template- haskell-2.10.0.0-inplace wired-in package ghc mapped to ghc-7.10.1-inplace wired-in package dph-seq not found. wired-in package dph-par not found. Hsc static flags: Loading package ghc-prim-0.4.0.0 ... linking ... done. *** gcc: /usr/bin/gcc -fno-stack-protector -DTABLES_NEXT_TO_CODE -L/5playpen/t-bepric/ghc-7.10.1-build/libraries/integer-gmp2/dist- install/build --print-file-name libgmp.so Loading package integer-gmp-1.0.0.0 ... linking ... done. Loading package base-4.8.0.0 ... linking ... done. wired-in package ghc-prim mapped to ghc-prim-0.4.0.0-inplace wired-in package integer-gmp mapped to integer-gmp-1.0.0.0-inplace wired-in package base mapped to base-4.8.0.0-inplace wired-in package rts mapped to builtin_rts wired-in package template-haskell mapped to template- haskell-2.10.0.0-inplace wired-in package ghc mapped to ghc-7.10.1-inplace wired-in package dph-seq not found. wired-in package dph-par not found. *** Chasing dependencies: Chasing modules from: Stable obj: [] Stable BCO: [] unload: retaining objs [] unload: retaining bcos [] Ready for upsweep [] Upsweep completely successful. *** Deleting temp files: Deleting: *** Chasing dependencies: Chasing modules from: *DebuggerCrash.hs Stable obj: [] Stable BCO: [] unload: retaining objs [] unload: retaining bcos [] Ready for upsweep [NONREC ModSummary { ms_hs_date = 2015-07-08 14:18:11 UTC ms_mod = Main, ms_textual_imps = [import (implicit) Prelude] ms_srcimps = [] }] *** Deleting temp files: Deleting: compile: input file DebuggerCrash.hs Created temporary directory: /tmp/ghc22370_0 *** Checking old interface for Main: [1 of 1] Compiling Main ( DebuggerCrash.hs, interpreted ) *** Parser: *** Renamer/typechecker: *** Desugar: Result size of Desugar (before optimization) = {terms: 16, types: 26, coercions: 0} Result size of Desugar (after optimization) = {terms: 12, types: 18, coercions: 0} *** Simplifier: Result size of Simplifier iteration=1 = {terms: 12, types: 20, coercions: 0} Result size of Simplifier = {terms: 12, types: 20, coercions: 0} *** Tidy Core: Result size of Tidy Core = {terms: 12, types: 20, coercions: 0} *** CorePrep: Result size of CorePrep = {terms: 16, types: 30, coercions: 0} *** ByteCodeGen: Upsweep completely successful. *** Deleting temp files: Deleting: /tmp/ghc22370_0/ghc22370_2.c /tmp/ghc22370_0/ghc22370_1.o Warning: deleting non-existent /tmp/ghc22370_0/ghc22370_2.c Warning: deleting non-existent /tmp/ghc22370_0/ghc22370_1.o Ok, modules loaded: Main. *Main> f A *** Parser: *** Desugar: *** Simplify: *** CorePrep: *** ByteCodeGen: True *Main> :break 5 Breakpoint 0 activated at DebuggerCrash.hs:5:9-20 *Main> f A *** Parser: *** Desugar: *** Simplify: *** CorePrep: *** ByteCodeGen: ghc-stage2: panic! (the 'impossible' happened) (GHC version 7.10.1 for x86_64-unknown-linux): ASSERT failed! file compiler/typecheck/TcUnify.hs line 1138 k_amp }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10616 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler