#10141: Kind inference regression in closed type families -------------------------------------+------------------------------------- Reporter: goldfire | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: 7.12.1 Component: Compiler | Version: 7.10.1-rc2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by goldfire): I've added a (not-yet-pushed) test case, but it's hard to see how to improve error messages. The problem is that the place that generates the kind errors is far from where we know whether or not we have a CUSK. I attempted to use `addErrCtxt` to include a note about CUSKs before kind- checking, but this note got appended to lots of errors that are clearly unrelated to CUSKs -- this is the wrong approach. I think the right approach is to somehow record in `TcM` that we're kind-checking a declaration which could potentially have a CUSK but in fact does not and then look there before reporting certain errors. But this is terribly heavy. Perhaps after my branch is merged, a way forward will present itself. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10141#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler