#16033: Rank-n typechecking regression between GHC 8.4 and 8.6 -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.8.1 Component: Compiler (Type | Version: 8.6.3 checker) | Resolution: | Keywords: RankNTypes Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"a1c3ad0450baedadc223969dd2b09f59872a38e7/ghc" a1c3ad0/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="a1c3ad0450baedadc223969dd2b09f59872a38e7" Add solveLocalEqualities to tcHsPatSigType This call plain missing, and as a result the casts messed up deep-skolemisation in tcSubType Fixes Trac #16033 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16033#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler