#14246: Probably AllowAmbiguousTypes + UndecidableInstances + TypeInType -------------------------------------+------------------------------------- Reporter: Toricon | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Resolution: | Keywords: Operating System: Windows | Architecture: x86_64 Type of failure: Compile-time | (amd64) crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #13271 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * related: => #13271 Comment: I don't know what `MCS.Core` is, so I have no way to test this code. That being said, this error message is identical to that of #13271, which has been fixed as of GHC 8.2.1. Can you test your code on 8.2.1 and see if you still experience the same error? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14246#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler