#6041: Program hangs when run under Ubuntu Precise ---------------------------+------------------------------------------------ Reporter: dsf | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.4.1 | Keywords: Os: Linux | Architecture: Unknown/Multiple Failure: Runtime crash | Testcase: Blockedby: | Blocking: Related: | ---------------------------+------------------------------------------------ This code hangs when running under Ubuntu Precise. However, it works in a Precise changeroot on an Ubuntu Lucid machine -- indicating it could be kernel specific. My guess would be that it would succeed on a Precise machine running a Lucid kernel, but we have not tried that.
Any of the following changes make the code work: 1. replacing 'readTVar u' with 'return ()' 2. removing the 'Wrapper' monad and just using 'StateT' 3. deriving the 'MonadState' instance instead of righting it by hand 4. copying the definition of 'modify' into the local module and use that instead of the imported version The final mystery: If the binary is built in a precise changeroot (where it works) and then copied to a precise machine ... it still works. And if it is built on a real precise machine, where it fails, it still fails when copied to a precise changeroot on a lucid machine. So, there's that. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/6041> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler _______________________________________________ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs