Re: [GHC] #10527: Panic Simplifier ticks exhausted with type families

#10527: Panic Simplifier ticks exhausted with type families -------------------------------------+------------------------------------- Reporter: sopvop | Owner: bgamari Type: bug | Status: new Priority: highest | Milestone: 7.10.2 Component: Compiler | Version: 7.10.1-rc1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by bgamari): I have also noticed that GHC 7.10.1 often appears to by simplifying inside of a `cast` when 7.10.2 is just working inside of `Const`. For instance, it is common to see the `SimplCont` of 7.10.1 terminates with, {{{#!hs CastIt Nth:1 (((forall a6 b. _R -> Control.Applicative.NTCo:Const[0] <a6>_R <b>_P)@"field1" Bug.:-> Bug.Expr GHC.Types.Int)@Bug.Rec '["field1" Bug.:-> Bug.Expr GHC.Types.Int, "field2" Bug.:-> Bug.Expr GHC.Types.Int, "id" Bug.:-> Bug.Expr GHC.Types.Int, "event_type" Bug.:-> Bug.Expr GHC.Types.Int]) Stop[BoringCtxt] "field1" Bug.:-> Bug.Expr GHC.Types.Int }}} whereas 7.10.2 will end in, {{{#!hs Stop[BoringCtxt] Control.Applicative.Const ("field1" Bug.:-> Bug.Expr GHC.Types.Int) (Bug.Rec '["field1" Bug.:-> Bug.Expr GHC.Types.Int, "field2" Bug.:-> Bug.Expr GHC.Types.Int, "id" Bug.:-> Bug.Expr GHC.Types.Int, "event_type" Bug.:-> Bug.Expr GHC.Types.Int]) }}} with the inner context being essentially identical. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10527#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler