Description of problem:

koji is missing a dependency on yum so download-build fails with a traceback:

# koji download-build 629499
Traceback (most recent call last):
  File "/bin/koji", line 56, in <module>
    import yum.comps
ImportError: No module named yum.comps

# dnf install yum

# koji download-build 629499
ipsilon-authldap-0.6.0-1.fc22.noarch.rpm                    |  31 kB  00:00 !!! 
...
profit!

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

koji-1.9.0-11.fc22.20150423git52a0188.noarch