4.15 Unable to customize guest name during installation with Virtual Machine Manager

During an installation with virt-manager, if you select a customized configuration and then edit the Name field to customize the virtual machine (VM) name, an error similar to the following occurs when you attempt to apply the changes:

Error apply changes: 'NoneType' object has no attribute 'rfind'

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/details.py", line 1887, in
    ret = self.config_overview_apply()
  File "/usr/share/virt-manager/virtManager/details.py", line 1979, in
  File "/usr/share/virt-manager/virtManager/domain.py", line 596, in
    new_nvram, old_nvram = self._copy_nvram_file(new_name)
  File "/usr/share/virt-manager/virtManager/domain.py", line 571, in
    nvram_dir = os.path.dirname(old_nvram.path)
  File "/usr/lib64/python2.7/posixpath.py", line 129, in dirname
    i = p.rfind('/') + 1
AttributeError: 'NoneType' object has no attribute 'rfind'

This issue is only encountered when attempting to customize the Name field. If you apply any other customizations prior to the installation, such as changes to Title or Description, the installation proceeds as expected. Note that you can edit the Name field after the installation completes, if desired.

(Bug ID 29954660)