#8994: type checker could not deduce ambiguous instances -------------------------------------+------------------------------------ Reporter: divip | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Resolution: invalid | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by divip): Thanks for the explanation. About my user experience: The example code was extracted from a bigger program. I did incremental refactoring steps on my program. In one step I introduced a new associated type which was independent of the rest of the program (like `type F a` above which should not interfere with defaulting), and my program stopped to compile. So I was almost sure this is a compiler bug. Improving on this behaviour is not very important for me, it was just unexpected during programming. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8994#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler