#13615: Nondeterminism in ‘pure’ function w/ parallel evaluation & memo combinators -------------------------------------+------------------------------------- Reporter: pacak | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: 8.2.1 Component: Compiler | Version: 8.2.1-rc2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect result | Unknown/Multiple at runtime | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by pacak): {{{ <bgamari> gamebooksolver-solvebook02: Those are expected to be equal(6030,6030) <bgamari> GHC has an interesting sense of equality }}} Code that generates this error looks like this and both `s'` and `s` are `Int`s. {{{ if s' /= s then error $ "Those are expected to be equal" ++ show (s', s) else xs' }}} I don't see how that's possible unless `Eq` instance for `Int` gets corrupted somehow. If that's the case - it also might mean `Num` instance is bogus as well and that results in wrong sum. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13615#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler