Description of problem:
Graphical install won't start on one of my machines (bug 498312), and this in turn triggers what appears to be a bug in kickstart %pre commands in text mode.

When it writes on the screen that it's running the pre commands, the second line on the screen has such noise as 'rhpl.executil waitpid: None', and it appears to run forever, even though the kickstart file says:
%pre
hostname libero
%end

After waiting a while, I switch to VT2, then back to VT1, and I see the following (incomplete) exception backtrace:

  File "/usr/lib/anaconda/kickstart.py", line 1087, in preScriptPass
    runPreScripts(anaconda, ksparser.handler.scripts)
  File "/usr/lib/anaconda/kickstart.py", line 1185, in runPreScripts
    map (lambda s: s.run("/", flags.serial, anaconda.intf), preScripts)
  File "/usr/lib/anaconda/kickstart.py , line 1185, in <lambda>
    map (lambda s: s.run("/", flags.serial, anaconda.intf), preScripts)
  File "/usr/lib/anaconda/kickstart.py , line 84, run
    root = scriptRoot)
  File "/usr/lib/anaconda/iutil.py", line 106, in execWithRedirect
    except OSError, (errno, msg):
ValueError: need more than 0 values to unpack
install exited abnormally [1/1]

Version-Release number of selected component (if applicable):
F11-Preview

How reproducible:
Every time

Steps to Reproduce:
1.Run kickstart install in text mode, with a %pre script