#14132: Report an error for a missing class instance before an error for type family instances of an associated type. -------------------------------------+------------------------------------- Reporter: duog | Owner: duog Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.2.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by duog): I tried moving those three `ReporterSpec`s to report2 (keeping their order, just adding them after "Dicts") and T12170a gave a core lint error (attached). I had assumed it was due to the invariant specified in the comment. I am obviously very new to the typechecker; my presumption was that insoluble constraints were ones that we couldn't defer by inserting a coercion, so it would be very bad to suppress those errors. That was my untrained reading of the lint error. However this must be wrong, because surely there's no problem inserting a coercion from Int to Bool. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14132#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler