#15125: Typeclass instance selection depends on the optimisation level -------------------------------------+------------------------------------- Reporter: nicuveo | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.2.2 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 nicuveo): I am afraid I still see this behaviour in 8.4.2... I replaced INCOHERENT with OVERLAPPABLE, built my small example with --resolver nightly-2018-05-09, and in both cases it shortcuts and picks the general instance and prints 0. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15125#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler