#8390: regression in handling of type variables in constraints on instances which do not appear in the instance head ----------------------------------------------+---------------------------- Reporter: aavogt | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.7 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects valid program | Unknown/Multiple Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: ----------------------------------------------+---------------------------- Comment (by aavogt): goldfire, you're asking for a message `suggested fix: -XAllowAmbiguousTypes'? The reasoning for rejecting the Compose f g instance by default makes sense here. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8390#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler