#15505: Assertion failures in tests T7224, T9201, LevPolyBounded -------------------------------------+------------------------------------- Reporter: osa1 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler (Type | Version: 8.5 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 simonpj): Problem is that * we call `zonkTcTypeToType` from `zonkTcMethInfoToMethInfo`, in `tcTyClDecl1` on class decls * when there is an unsolved (actually insoluble) residual constraint * the `CoVarHole` for that equality constraint is, of course (since it is solved) * but the zonker complains about an unfilled-in coercion hole. The assertion for an unfilled coercion hole is skipped if there are any type errors (and rightly so): see `TcHsSyn.zonkCoHole`. But at this moment we'd only called `zonkLocalEqualities` not `zonkEqualities`, so we hadn't actually added the error to in the Tc monad. Solution: call `solveEqualities` in `tcTyClDecl`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15505#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler