Version comparator fails for client dev version

2014-06-12 14:44:19,385 6752 140201824802560 DEBUG    nxdrive.updater    Fetched client minimum version for server version 5.9.4-I20140415_0120 from http://localhost:8001/dist/5.9.4-I20140415_0120.json: 1.3.0610
2014-06-12 14:44:19,389 6752 140201824802560 ERROR    nxdrive.commandline Error executing 'launch': invalid literal for int() with base 10: '3-dev'
Traceback (most recent call last):
  File "/home/ataillefer/sources/nuxeo/addons/nuxeo-drive/nuxeo-drive-client/nxdrive/commandline.py", line 345, in handle
    return handler(options)
  File "/home/ataillefer/sources/nuxeo/addons/nuxeo-drive/nuxeo-drive-client/nxdrive/commandline.py", line 359, in launch
    app = Application(self.controller, options)
  File "/home/ataillefer/sources/nuxeo/addons/nuxeo-drive/nuxeo-drive-client/nxdrive/gui/application.py", line 151, in __init__
    self.settings()
  File "/home/ataillefer/sources/nuxeo/addons/nuxeo-drive/nuxeo-drive-client/nxdrive/gui/application.py", line 835, in settings
    self.refresh_update_status()
  File "/home/ataillefer/sources/nuxeo/addons/nuxeo-drive/nuxeo-drive-client/nxdrive/gui/application.py", line 188, in refresh_update_status
    self.controller.get_version(), server_version))
  File "/home/ataillefer/sources/nuxeo/addons/nuxeo-drive/nuxeo-drive-client/nxdrive/updater.py", line 302, in get_update_status
    latest_version = self.get_latest_compatible_version(server_version)
  File "/home/ataillefer/sources/nuxeo/addons/nuxeo-drive/nuxeo-drive-client/nxdrive/updater.py", line 286, in get_latest_compatible_version
    client_versions = sorted(client_versions, cmp=version_compare)
  File "/home/ataillefer/sources/nuxeo/addons/nuxeo-drive/nuxeo-drive-client/nxdrive/updater.py", line 135, in version_compare
    x_number = int(x_number)
ValueError: invalid literal for int() with base 10: '3-dev'