koji scratch builds failing

[Manuel Wolfshant]

Hey
 I am planning on reviewing lsvpd, but as I do not have a PPC box to 
build on, I tried to do koji scratch builds. Unfortunately I keep 
getting errors similar to:

[wolfy at wolfy tmp]$ koji build --scratch --arch-override=ppc dist-rawhide 
lsvpd-1.6.2-3.src.rpm
Uploading srpm: lsvpd-1.6.2-3.src.rpm
[====================================] 100% 00:00:10  233.24 Kb   21.65 
Kb/sec
Created task: 517533
Task info: http://koji.fedoraproject.org/koji/taskinfo?taskID=517533
Watching tasks (this may be safely interrupted)...
517533 build (dist-rawhide, lsvpd-1.6.2-3.src.rpm): free
517533 build (dist-rawhide, lsvpd-1.6.2-3.src.rpm): free -> open 
(ppc4.fedora.phx.redhat.com)
  517534 buildArch (lsvpd-1.6.2-3.src.rpm, ppc): free
  517534 buildArch (lsvpd-1.6.2-3.src.rpm, ppc): free -> open 
(ppc2.fedora.redhat.com)
  517534 buildArch (lsvpd-1.6.2-3.src.rpm, ppc): open 
(ppc2.fedora.redhat.com) -> FAILED: BuildrootError: could not init mock 
buildroot, mock exited with status 20
  0 free  1 open  0 done  1 failed
517533 build (dist-rawhide, lsvpd-1.6.2-3.src.rpm): open 
(ppc4.fedora.phx.redhat.com) -> FAILED: BuildrootError: could not init 
mock buildroot, mock exited with status 20
  0 free  0 open  0 done  2 failed

The errors are identical even if I do not use the override arch flag and 
have happened several times, 8 hours apart, on different builders.
Am I doing something wrong or is  koji acting funny on me ?