#11663: GHC 8.0 type assignment in arguments of lambda working without Scoped Type Variables -------------------------------------+------------------------------------- Reporter: bitemyapp | Owner: Type: bug | Status: patch Priority: high | Milestone: 8.0.1 Component: Compiler | Version: 8.0.1-rc2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2054 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Ben Gamari <ben@…>): In [changeset:"d5d6804d37960ece2652196f3661604a70c12ffc/ghc" d5d6804d/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="d5d6804d37960ece2652196f3661604a70c12ffc" rename: Disallow type signatures in patterns in plain Haskell This should require -XScopedTypeVariables. It seems this was previously handled by RnTypes.rnHsBndrSig which called RnTypes.badKindSigErr but this was broken in Simon's refactor of wildcards, 1e041b7382b6aa329e4ad9625439f811e0f27232. Here we re-introduce a check in RnPat. See #11663. Test Plan: Validate with `T11663` Reviewers: austin, simonpj Reviewed By: austin Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2054 GHC Trac Issues: #11663 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11663#comment:6> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler