#15039: Bizarre pretty-printing of inferred Coercible constraint in partial type signature -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler (Type | Version: 8.4.1 checker) | Keywords: Resolution: | PartialTypeSignatures, TypeInType Operating System: Unknown/Multiple | Architecture: Type of failure: Poor/confusing | Unknown/Multiple error message | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): I think comment:6 is a red herring. Why is GHC attempting to report about `~R#` at all here? The type of the hole is really `Coercible a b`. I don't think this is a pretty-printing issue. Instead, the solver needs to be taught somewhere to transmute `a ~R# b` constraints to `Coercible a b` constraints. But where? Do we do this for nominal equality anywhere? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15039#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler