Hi,
On Thu, Sep 5, 2013 at 9:10 PM, Kazu Yamamoto
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
I wonder if this issue could have been introduced by the commit: https://github.com/ghc/ghc/commit/6770663f764db76dbb7138ccb3aea0527d194151 It looks like after the commit, addCFinalizerToWeak# can call into the GC with the closure lock held. This means the info pointer points to stg_WHITEHOLE_info, breaking the asserted invariant. I haven't done any testing to confirm this, however. -- Takano Akio