#11961: PatBind test suite failure with `-DDEBUG` -------------------------------------+------------------------------------- Reporter: nomeata | Owner: Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 8.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I get {{{ Compile failed (status 256) errors were: ghc-stage2: panic! (the 'impossible' happened) (GHC version 8.1.20160420 for x86_64-unknown-linux): ASSERT failed! CallStack (from HasCallStack): assertPprPanic, called at compiler/types/TyCoRep.hs:2082:56 in ghc:TyCoRep checkValidSubst, called at compiler/types/TyCoRep.hs:2118:17 in ghc:TyCoRep substTy, called at compiler/types/TyCoRep.hs:2060:3 in ghc:TyCoRep in_scope InScope {a_apN t_apW a_apX} tenv [apC :-> t_apW[tau:3], apN :-> a_apX[tau:3]] tenvFVs [apD :-> t_apD[tau:3], apW :-> t_apW[tau:3], apX :-> a_apX[tau:3]] cenv [] cenvFVs [] tys [a_apN[sk] -> a_apN[sk]] cos [] Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug *** unexpected failure for PatBind(normal) }}} with a `-DDEBUG` build, e.g. on travis: https://s3.amazonaws.com/archive .travis-ci.org/jobs/124426776/log.txt -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11961 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler