Xpra: Ticket #813: CentOS 6.4 client throwing xpra main error

In an effort to test for #700 & #764, I installed the CentOS 6.4 0.15.0 client from your beta repo:

yum localinstall http://xpra.org/beta/CentOS/6.4/x86_64/xpra-0.15.0-0.20150213.el6_4.x86_64.rpm http://xpra.org/beta/CentOS/6.4/x86_64/xpra-common-0.15.0-0.20150213.el6_4.noarch.rpm

When trying to run it though, or even just trying to run xpra --version, I get the following traceback:

$ xpra --version
xpra main error:
Traceback (most recent call last):
  File "/usr/lib64/python2.6/site-packages/xpra/scripts/main.py", line 105, in main
    defaults = make_defaults_struct()
  File "/usr/lib64/python2.6/site-packages/xpra/scripts/config.py", line 555, in make_defaults_struct
    defaults = read_xpra_defaults()
  File "/usr/lib64/python2.6/site-packages/xpra/scripts/config.py", line 225, in read_xpra_defaults
    dirs = [get_default_conf_dir(), get_system_conf_dir(), get_user_conf_dir()]
  File "/usr/lib64/python2.6/site-packages/xpra/platform/paths.py", line 31, in get_system_conf_dir
    prefix = get_install_prefix()
  File "/usr/lib64/python2.6/site-packages/xpra/platform/xposix/paths.py", line 14, in get_install_prefix
    if __file__.startswith(site.getuserbase()):
AttributeError: 'module' object has no attribute 'getuserbase'