[Yt-dev] RMS mass overdensity method

[Matthew Turk]

> I just installed a piping fresh new copy of yt, along with the google code mpi4py, and a parallel run is crashing in exactly the same place as before.
>
> I think I need to try this stuff tomorrow on Kraken.

As near as I can tell, the only thing that's really happening in that
run that would use the MPI stack is ... nothing, after initialization.

There is a possibility that the stack could be corrupted or something
during the barrierization.  But ... I don't know.  At this point, I'm
kind of out of ideas.

I'll be gone all day tomorrow until the evening driving to UCSB, but
I'll be back late at night and maybe for a little while in the early
or late afternoon.  Let us know how Kraken goes, because this is
confusing to me.  Confusing and infuriating.

-Matt