A bug of multicore IO manager

[Kazu Yamamoto ( 山本和彦 )]

Hi,

> If you need two Ctrl-Cs to kill the program, it probably means that it
> deadlocked somewhere, maybe in the RTS.  Kazu: if you can attach to
> the deadlocked process with gdb and get stack traces of all the
> threads, that might help.

To debug with GDB, I complied Mighty with "-debug". This changes the
behavior and I got the following error:

mighty-20130905: internal error: ASSERTION FAILED: file rts/sm/MarkWeak.c, line 371 

    (GHC version 7.7.20130901 for i386_unknown_linux)
    Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

Simon, can you tell what's going on?

--Kazu