Re: [GHC] #15438: Misleading error message for higher rank type

#15438: Misleading error message for higher rank type -------------------------------------+------------------------------------- Reporter: simonpj | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.4.3 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 Simon Peyton Jones ): In [changeset:"12c0f03a66bcd978bda6472384ddc0348c5a1d7a/ghc" 12c0f03a/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="12c0f03a66bcd978bda6472384ddc0348c5a1d7a" Set GenSigCtxt for the argument part of tcSubType The reason for this change is described in TcUnify Note [Settting the argument context], and Trac #15438. The only effect is on error messages, where it stops GHC reporting an outright falsity (about the type signature for a function) when it finds an errors in a higher-rank situation. The testsuite changes in this patch illustrate the problem. }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15438#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler