#8651: 'Untouchable' error when using type function in class constraint in rank-2 type --------------------------------------------+------------------------------ Reporter: sbarclay | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type checker) | Version: 7.7 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: #8644 | #7594 --------------------------------------------+------------------------------ Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"5d2fb2ee94fea4cf62ba767eb1555e42f4f21f46/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="5d2fb2ee94fea4cf62ba767eb1555e42f4f21f46" Further refine the test for 'given' equalities Trac #8651 revealed that my previous fix (itself in response to #8644) wasn't quite right. The plan, using the CtOrigin to identify constraints arising from flattening, is described in TcSimplify, Note [When does an implication have given equalities?] }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8651#comment:1> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler