Description of problem:
Yum can't install noarch rpm due to py keyerror

Version-Release number of selected component (if applicable):
yum-2.1.11-2

How reproducible:
always

Steps to Reproduce:
1.rpm -e selinux-policy-targeted
2.yum install selinux-policy-targeted
  
Actual results:
Setting up Install Process
Setting up Repo:  development
repomd.xml                100% |=========================| 1.1 kB    00:00
Reading repository metadata in from local files
developmen: ################################################## 3426/3426
Traceback (most recent call last):
  File "/usr/bin/yum", line 8, in ?
    yummain.main(sys.argv[1:])
  File "/usr/share/yum-cli/yummain.py", line 68, in main
    result, resultmsgs = base.doCommands()
  File "/usr/share/yum-cli/cli.py", line 374, in doCommands
    return self.installPkgs()
  File "/usr/share/yum-cli/cli.py", line 734, in installPkgs
    pkglist = returnBestPackages(toBeInstalled)
  File "/usr/lib/python2.3/site-packages/yum/packages.py", line 123,
in returnBestPackages
    elif rpmUtils.arch.isMultiLibArch(arch=a):
  File "/usr/lib/python2.3/site-packages/rpmUtils/arch.py", line 69,
in isMultiLibArch
    if multilibArches.has_key(arches[arch]):
KeyError: 'noarch'
[root:~] #

Expected results:
Yum to download and install the package.

Additional info: