#14745: Functional dependency conflicts in givens -------------------------------------+------------------------------------- Reporter: simonpj | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.2 Resolution: | Keywords: FunDeps 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 Simon Peyton Jones <simonpj@…>): In [changeset:"efba054640d3418d7477316ae0c1e992d0aa0f22/ghc" efba0546/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="efba054640d3418d7477316ae0c1e992d0aa0f22" Prioritise equalities when solving, incl deriveds We already prioritise equalities when solving, but Trac #14723 showed that we were not doing so consistently enough, and as a result the type checker could go into a loop. Yikes. See Note [Prioritise equalities] in TcSMonad. Fixng this bug changed the solve order enough to demonstrate a problem with fundeps: Trac #14745. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14745#comment:2> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler