Description of problem: Abort with traceback from lorax during pungi compose of .iso for DVD.


Version-Release number of selected component (if applicable):
lorax-18.20-1.fc18.x86_64
anaconda-18.8-1.fc18.x86_64
pungi-2.12-1.fc18.noarch


How reproducible: every time (3 for 3)


Steps to Reproduce:
1./usr/bin/pungi -c fedora-install-fedora-$VERSION.ks \
	--destdir=$DESTDIR --name Fedora --ver $VERSION --nosource

2.
3.
  
Actual results:
   [snip]
running runtime-cleanup.tmpl
creating the runtime image
mke2fs 1.42.5 (29-Jul-2012)
Discarding device blocks: done                            
Filesystem label=Anaconda
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
65536 inodes, 1048576 blocks
0 blocks (0.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=68157440
128 block groups
8192 blocks per group, 8192 fragments per group
512 inodes per group
Superblock backups stored on blocks: 
	8193, 24577, 40961, 57345, 73729, 204801, 221185, 401409, 663553, 
	1024001

Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done   

Can't stat exclude path "/selinux", No such file or directory - ignoring.
umount: /dev/shm/pungi-1946/lorax.imgutils.QoEBjK: target is busy.
        (In some cases useful info about processes that use
         the device is found by lsof(8) or fuser(1))
losetup: /dev/loop0: detach failed: Device or resource busy
Traceback (most recent call last):
  File "/usr/bin/pungi", line 256, in <module>
    main()
  File "/usr/bin/pungi", line 146, in main
    mypungi.doBuildinstall()
  File "/usr/lib/python2.7/site-packages/pypungi/__init__.py", line 913, in doBuildinstall
    workdir=workdir, outputdir=outputdir)
  File "/usr/lib/python2.7/site-packages/pylorax/__init__.py", line 272, in run
    compression=compression, compressargs=compressargs)
  File "/usr/lib/python2.7/site-packages/pylorax/treebuilder.py", line 164, in create_runtime
    runcmd(cmd, root=mnt)
  File "/usr/lib/python2.7/site-packages/pylorax/imgutils.py", line 234, in __exit__
    umount(self.mnt)
  File "/usr/lib/python2.7/site-packages/pylorax/imgutils.py", line 137, in umount
    mnt, rv, count, maxretry)
UnboundLocalError: local variable 'rv' referenced before assignment


Expected results: no problem


Additional info: log file shows:
-----
   [snip]
pylorax.imgutils.DEBUG: make tmp mountdir /dev/shm/pungi-1946/lorax.imgutils.1YNfdW
program.INFO: Running... mount /dev/loop0 /dev/shm/pungi-1946/lorax.imgutils.1YNfdW
pylorax.imgutils.DEBUG: copytree /sdd15/ext4-data/Fedora18/work/x86_64/yumroot /dev/shm/pungi-1946/lorax.imgutils.1YNfdW
program.INFO: Running... cp -a . /dev/shm/pungi-1946/lorax.imgutils.1YNfdW
program.INFO: chdiring into /sdd15/ext4-data/Fedora18/work/x86_64/yumroot
program.INFO: Running... umount /dev/shm/pungi-1946/lorax.imgutils.1YNfdW
pylorax.imgutils.DEBUG: remove tmp mountdir /dev/shm/pungi-1946/lorax.imgutils.1YNfdW
program.INFO: Running... losetup --detach /dev/loop0
program.INFO: Running... losetup --find --show /sdd15/ext4-data/Fedora18/work/x86_64/installroot/images/runtime-workdir/LiveOS/rootfs.img
program.INFO: /dev/loop0
pylorax.imgutils.DEBUG: make tmp mountdir /dev/shm/pungi-1946/lorax.imgutils.QoEBjK
program.INFO: Running... mount /dev/loop0 /dev/shm/pungi-1946/lorax.imgutils.QoEBjK
program.INFO: Running... setfiles -e /proc -e /sys -e /dev -e /selinux /etc/selinux/targeted/contexts/files/file_contexts /
program.INFO: chrooting into /dev/shm/pungi-1946/lorax.imgutils.QoEBjK
program.ERROR: Can't stat exclude path "/selinux", No such file or directory - ignoring.
program.INFO: Running... umount /dev/shm/pungi-1946/lorax.imgutils.QoEBjK
program.ERROR: umount: /dev/shm/pungi-1946/lorax.imgutils.QoEBjK: target is busy.
program.ERROR:         (In some cases useful info about processes that use
program.ERROR:          the device is found by lsof(8) or fuser(1))
program.INFO: Running... losetup --detach /dev/loop0
program.ERROR: losetup: /dev/loop0: detach failed: Device or resource busy
   [EOF]
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