#10598: DeriveAnyClass and GND don't work well together -------------------------------------+------------------------------------- Reporter: osa1 | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by kosmikus): I think the confusion is understandable, because a large design space is being discussed here. The issue as reported is mainly about interaction between `GeneralizedNewtypeDeriving` and `DeriveAnyClass`. There are four options specified here: https://ghc.haskell.org/trac/ghc/wiki/Commentary/Compiler/GenericDeriving#In... All four have disadvantages, and unfortunately the document does not say which of the four options actually has been implemented. It seems from the current behaviour of GHC like the implementation is along the lines of option 2 (and perhaps 3). However, even then we still have the fact that the error messages don't seem to properly reflect what is going on. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10598#comment:18 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler