#11524: Something is amiss with quantification in pattern synonym type signatures -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: high | Milestone: 8.0.1 Component: Compiler (Type | Version: 8.0.1-rc1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * cc: niteria (added) Comment:
It's a bug in the pretty-printer.
Actually, I'm not entirely sure that this is the whole story. After pulling I'm now seeing, {{{ $ inplace/bin/ghc-stage1 hi.hs [1 of 1] Compiling Main ( hi.hs, hi.o ) ghc-stage1: panic! (the 'impossible' happened) (GHC version 8.1.20160124 for x86_64-unknown-linux): ASSERT failed! file compiler/types/TyCoRep.hs line 1919 in_scope InScope {k_aB4 k_aJd a_aJe b_aJf} tenv [auE :-> a_aJe[tau:5], auF :-> b_aJf[tau:5], aB3 :-> k_aJd[tau:5]] cenv [] tys [fun_auD[sk] ~ a_auE[sk] b_auF[sk]] cos [] needInScope [auD :-> fun_auD[sk], aB4 :-> k_aB4[tau:1]] Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} Presumably this is niteria's in-scope set checks in action. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11524#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler