#14904: Compiler panic (piResultTy) -------------------------------------+------------------------------------- Reporter: kcsongor | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: 8.6.1 Component: Compiler (Type | Version: 8.2.2 checker) | Resolution: fixed | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | typecheck/should_fail/T14904a, | typecheck/should_fail/T14904b Blocked By: | Blocking: Related Tickets: #14873 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by sighingnow): For `ASSERT`-enabled ghc-stage2, the testcase T14904b still raises an "ASSERT failed!" panic. Not sure if it's worth further fix. T14904b.hs: {{{#!hs import Data.Kind type family F f :: Type where F ((f :: forall a. g a) :: forall a. g a) = Int }}} The panic error message: {{{ λ ginplace\bin\ghc-stage2.exe--make T.hs [1 of 1] Compiling T14904b ( T.hs, T.o ) ghc-stage2.exe: panic! (the 'impossible' happened) (GHC version 8.5.20180608 for x86_64-unknown-mingw32): ASSERT failed! 1 0 k_aWM[tau:0] (g_aWI[sig:0] |> {co_aWV}) a_aX4[tau:0] Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler\utils\Outputable.hs:1161:37 in ghc:Outputable pprPanic, called at compiler\utils\Outputable.hs:1220:5 in ghc:Outputable assertPprPanic, called at compiler\\typecheck\\TcMType.hs:745:54 in ghc:TcMType CallStack (from -prof): TcRnDriver.tc_rn_src_decls (compiler\typecheck\TcRnDriver.hs:(496,4)-(560,7)) TcRnDriver.tcRnSrcDecls (compiler\typecheck\TcRnDriver.hs:259:25-65) }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14904#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler