Re: [GHC] #10684: Error cascade when unrelated class derivation fails

#10684: Error cascade when unrelated class derivation fails -------------------------------------+------------------------------------- Reporter: ezyang | Owner: (none) Type: bug | Status: patch Priority: low | Milestone: Component: Compiler (Type | Version: 7.11 checker) | 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:D3771 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Ryan Scott ): In [changeset:"6bb32ba78580271921e3d5c3c98afac2c1b68de4/ghc" 6bb32ba/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="6bb32ba78580271921e3d5c3c98afac2c1b68de4" Fix #10684 by processing deriving clauses with finer grain Summary: Previously, one could experience error cascades with deriving clauses when one class in a set of many failed to derive, causing the other derived classes to be skipped entirely and resulting in other errors down the line. The solution is to process each class in a data type's set of deriving clauses individually, and engineer it so that failure to derive an individual class within that set doesn't cancel out the others. Test Plan: make test TEST="T10684 T12801" Reviewers: austin, bgamari, simonpj Reviewed By: simonpj Subscribers: simonpj, rwbarton, thomie GHC Trac Issues: #10684, #12801 Differential Revision: https://phabricator.haskell.org/D3771 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10684#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler