#13410: GHC HEAD regression: Template variable unbound in rewrite rule -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: simonpj Type: bug | Status: new Priority: highest | Milestone: 8.2.1 Component: Compiler | Version: 8.0.1 Resolution: | Keywords: JoinPoints, | SpecConstr Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by simonpj): * owner: (none) => simonpj Comment: I know exactly what is happening here. Just starved of time to fix it -- and next week looks little better. In brief: `TyCoRep.substCoVarBndr` is replacing occurrences of the binder with `Refl` in the LHS of a rule. Solution: `mkCoVarCo` should not replace varaibles with `Refl`; but `optCoercion` should do so instead. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13410#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler