x86_64 devel tree install exception

[Brian Stretch]

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=116511

In short, I mirrored x86_64 devel today (filtering out SRPMS, headers,
and debug dirs), ran genhdlist, burned a DVD, tried installing, and
got this exception during post-install (after the RPMS were installed):

...
/usr/bin/anaconda/packages.py, line 1091, doPostInstall devnull =
os.open("/dev/null", os.O_RDRW)
OSError: [Errno 1] Operation not permitted: '/dev/null'

But that line is the same in anaconda from FC1, so I'm confused. 

Anyone else get this?  Should I be testing the devel tree like this
or should I start with test release .iso sets?  I've had good luck
making updated FC1 DVDs so I think I put the devel tree DVD
together right.  Just wanted to play with the latest and greatest ;-).