Description of problem:
recently updated tmux-powerline via yum. Run tmux and the error occured. 

Version-Release number of selected component:
powerline-1.3.1-2.fc20

Additional info:
reporter:       libreport-2.2.3
cmdline:        /usr/bin/python /usr/bin/powerline-config tmux source
dso_list:       python-libs-2.7.5-15.fc20.x86_64
executable:     /usr/bin/powerline-config
kernel:         3.17.7-200.fc20.x86_64
runlevel:       N 5
type:           Python
uid:            1000

Truncated backtrace:
subprocess.py:542:check_call:CalledProcessError: Command '[u'tmux', u'refresh-client']' returned non-zero exit status 1

Traceback (most recent call last):
  File "/usr/bin/powerline-config", line 22, in <module>
    args.function(pl, args)
  File "/home/jorden/.local/lib/python2.7/site-packages/powerline/commands/config.py", line 15, in __call__
    self.function(*args, **kwargs)
  File "/home/jorden/.local/lib/python2.7/site-packages/powerline/bindings/config.py", line 77, in source_tmux_files
    run_tmux_command('refresh-client')
  File "/home/jorden/.local/lib/python2.7/site-packages/powerline/bindings/tmux/__init__.py", line 32, in run_tmux_command
    _run_tmux(subprocess.check_call, args)
  File "/home/jorden/.local/lib/python2.7/site-packages/powerline/bindings/tmux/__init__.py", line 27, in _run_tmux
    return runner([get_tmux_executable_name()] + list(args))
  File "/usr/lib64/python2.7/subprocess.py", line 542, in check_call
    raise CalledProcessError(retcode, cmd)
CalledProcessError: Command '[u'tmux', u'refresh-client']' returned non-zero exit status 1

Local variables in innermost frame:
cmd: [u'tmux', u'refresh-client']
retcode: 1
popenargs: ([u'tmux', u'refresh-client'],)
kwargs: {}