Are you sure you have seen GHC ask you to report a bug when running a
#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 nh2): (Small digression:) Replying to [comment:1 rwbarton]: program compiled by GHC (other than GHC itself)? I don't think that ever happens. @rwbarton: Actually, I did find such a case, I have one right here: A yesod webserver that when compiled without `-threaded`, and Ctrl-C'd, throws the following error: {{{ src/main/Main Development ^CMain: internal error: removeFromQueues: 22294 (GHC version 7.10.2 for x86_64_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Aborted (core dumped) }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11172#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler