On the subject of the actual panic observed in this ticket, I don't
#15290: QuantifiedConstraints: panic "addTcEvBind NoEvBindsVar" -------------------------------------+------------------------------------- Reporter: goldfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.4.3 Resolution: | Keywords: | QuantifiedConstraints Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: quantified- | constraints/T15290, T15290a Blocked By: | Blocking: 9123, 14883 Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): think Simon's commit quite fixed it. I'm still observing the panic on commit 122ba98af22c2b016561433dfa55bbabba98d972 with this program (taken from #14883): Are you sure? It compiles on HEAD for me. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15290#comment:28 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler