#12907: ExtendedDefaultRules-related regression in GHC 8.0.2 -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: Type: bug | Status: new Priority: high | Milestone: 8.0.2 Component: Compiler (Type | Version: 8.0.2-rc1 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 goldfire): I agree with comment:2. The change to reject the program reported was intentional, following the Report. When `-XExtendedDefaultRules` is in effect, the program given is accepted, as `Bool` is a member of several of the classes defaultable under the extended rules. I'd be willing to consider other designs here, but I believe what's implemented is the most faithful to the Report. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12907#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler