#7636: threadStackUnderflow: not enough space for return values -------------------------------+-------------------------------------------- Reporter: mojojojo | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.1 Keywords: | Os: MacOS X Architecture: x86_64 (amd64) | Failure: None/Unknown Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | -------------------------------+-------------------------------------------- Comment(by simonmar): Could I get you to do some debugging for me? I need you to compile the program with `-debug`, and then run it under gdb. When it crashes, you should be able to say `bt` and get a backtrace that includes `threadStackUnderflow`, in particular this bit of code: {{{ // we have some return values to copy to the old stack if ((W_)(new_stack->sp - new_stack->stack) < retvals) { barf("threadStackUnderflow: not enough space for return values"); } }}} I need to know the values of `retvals`, `new_stack->sp`, and `new_stack->sp`. I think this crash can occur, but it should be very very very rare. Before I fix it, I need to ensure that something else hasn't gone wrong to cause this crash to happen, because then I'd need to find the root cause before adding a workaround. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7636#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler