virt-manager: ‘NoneType’ object has no attribute ‘cpus’

After upgrading my Fedora 20 Xen hypervisor to virt-manager 1.0.0, I noticed that I couldn’t open the console or VM details for any of my guests. Running virt-manager --debug gave me the following traceback:

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/engine.py", line 803, in _show_vm_helper
    details = self._get_details_dialog(uri, uuid)
  File "/usr/share/virt-manager/virtManager/engine.py", line 760, in _get_details_dialog
    obj = vmmDetails(con.get_vm(uuid))
  File "/usr/share/virt-manager/virtManager/details.py", line 530, in __init__
    self.init_details()
  File "/usr/share/virt-manager/virtManager/details.py", line 990, in init_details
    for name in [c.model for c in cpu_values.cpus]:
AttributeError: 'NoneType' object has no attribute 'cpus'
[Tue, 04 Mar 2014 22:13:31 virt-manager 21019] DEBUG (error:84) error dialog message:
summary=Error launching details: 'NoneType' object has no attribute 'cpus'
details=Error launching details: 'NoneType' object has no attribute 'cpus'

I opened a bug report and the fix was committed upstream today. If you want to make these updates to your Fedora 20 server before the update package is available, just snag the three RPM’s from koji and install them:

mkdir /tmp/virt-manager
cd /tmp/virt-manager
wget http://kojipkgs.fedoraproject.org/packages/virt-manager/1.0.0/4.fc20/noarch/virt-install-1.0.0-4.fc20.noarch.rpm
wget http://kojipkgs.fedoraproject.org/packages/virt-manager/1.0.0/4.fc20/noarch/virt-manager-1.0.0-4.fc20.noarch.rpm
wget http://kojipkgs.fedoraproject.org/packages/virt-manager/1.0.0/4.fc20/noarch/virt-manager-common-1.0.0-4.fc20.noarch.rpm
yum localinstall *.rpm

UPDATE: Thanks to Cole’s comment below, you can actually pull in the RPM’s using koji directly:

koji download-build virt-manager-1.0.0-4.fc20