#8462: Compiler crash on invalid type class instance -----------------------------------+--------------------------------------- Reporter: thomaseding | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.4.2 Keywords: | Operating System: MacOS X Architecture: | Type of failure: Compile-time crash Unknown/Multiple | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | -----------------------------------+--------------------------------------- If you try compiling the following code, the compiler crashes {{{ class Foo a where foo :: a -> () class Bar a where bar :: a -> () instance (Foo a) => (Bar a -> ()) where bar = undefined }}} {{{ *** Exception: compiler/rename/RnSource.lhs:430:14-81: Irrefutable pattern failed for pattern Data.Maybe.Just (inst_tyvars, _, SrcLoc.L _ cls, _) }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8462 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler