#11172: Turning on optimisations produces Impossible case alternative -------------------------------------+------------------------------------- Reporter: nh2 | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.10.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Runtime crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by thomie): I got this far using HEAD: {{{ Preprocessing library free-4.12.1... [ 1 of 16] Compiling Control.Monad.Free.TH ( src/Control/Monad/Free/TH.hs, dist/build/Control/Monad/Free/TH.o ) src/Control/Monad/Free/TH.hs:235:5: error: • The constructor ‘DataConI’ should have 3 arguments, but has been given 4 • In the pattern: DataConI _ _ tname _ In a case alternative: DataConI _ _ tname _ -> genFree typeSig (Just [cname]) tname In a stmt of a 'do' block: case info of { DataConI _ _ tname _ -> genFree typeSig (Just [cname]) tname _ -> fail "makeFreeCon expects a data constructor" } Failed to install free-4.12.1 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11172#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler