#8132: Warning for Typeable instances misplaced -------------------------------------------------+------------------------- Reporter: scottgw | Owner: Type: bug | dreixel Priority: normal | Status: new Component: Compiler | Milestone: Resolution: | Version: 7.7 Operating System: Unknown/Multiple | Keywords: Type of failure: Incorrect warning at | Architecture: compile-time | Unknown/Multiple Test Case: | Difficulty: Blocking: | Unknown | Blocked By: | Related Tickets: -------------------------------------------------+------------------------- Comment (by scottgw): The disadvantage of amending the existing error is that it separates cause of the error from its from it symptom, and also doesn't pinpoint the cause reliably (You didn't write an instance! Or maybe you did and I ignored it!). The disadvantage of making a new error for this case is that clients who don't need the instance won't be able to compile until the package is fixed. I'm not sure what should constitute an error, but if GHC is just throwing these instances away because they are not allowed, then perhaps it makes sense to just disallow them. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8132#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler