#5902: Cannot tell from an exception handler whether the exception was asynchronous ---------------------------------+------------------------------------------ Reporter: simonmar | Owner: simonmar Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Compiler | Version: 7.4.1 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | ---------------------------------+------------------------------------------ Comment(by simonmar): Any time there's a catch/rethrow inside an `unsafePerformIO` we'll have this problem. So in the specific case of the GHC API it would help to know where this is happening, and whether we can avoid it. One way I can think of that might help in general is to have a special kind of catch that doesn't catch asynchronous exceptions. So in cases like your example, `catchIOError` would use the special sync-only catch internally, and would ignore the async exception. However, this unfortunately doesn't help with `bracket` and `finally`, which need to do some cleanup in the exception handler, and I suspect these are more common than `catch`. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5902#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler