#15073: Unable to newtype derive `Prim` via DerivingStrategies -------------------------------------+------------------------------------- Reporter: fosskers | Owner: (none) Type: bug | Status: patch Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.2.2 Resolution: | Keywords: deriving Operating System: Unknown/Multiple | Architecture: x86_64 | (amd64) Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D4620 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Ben Gamari <ben@…>): In [changeset:"0c7db226012b5cfafc9a38bfe372661672ec8900/ghc" 0c7db226/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="0c7db226012b5cfafc9a38bfe372661672ec8900" Fix #15073 by suggesting UnboxedTuples in an error message Under certain circumstances, `GeneralizedNewtypeDeriving` can emit code which uses unboxed tuple types, but if `UnboxedTuples` wasn't enabled, the error message that GHC gave didn't make it very clear that it could be worked around by explicitly enabling the extension. Easily fixed. Test Plan: make test TEST=T15073 Reviewers: bgamari Reviewed By: bgamari Subscribers: simonpj, thomie, carter GHC Trac Issues: #15073 Differential Revision: https://phabricator.haskell.org/D4620 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15073#comment:8> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler