ie, on a system where avahi was not started? (or was the port blocked?), this error occurred (which is obscure to say the least):

Exception in thread avahi_publisher for: [('0.0.0.0', 35941)]:
Traceback (most recent call last):
  File "/usr/lib64/python2.6/threading.py", line 525, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.6/site-packages/shifter/net/avahi_publisher.py", line 138, in run
    self.bus.get_object(avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER),
  File "/usr/lib/python2.6/site-packages/dbus/bus.py", line 244, in get_object
    follow_name_owner_changes=follow_name_owner_changes)
  File "/usr/lib/python2.6/site-packages/dbus/proxies.py", line 241, in __init__
    self._named_service = conn.activate_name_owner(bus_name)
  File "/usr/lib/python2.6/site-packages/dbus/bus.py", line 178, in activate_name_owner
    return self.get_name_owner(bus_name)
  File "/usr/lib/python2.6/site-packages/dbus/bus.py", line 355, in get_name_owner
    's', (bus_name,), utf8_strings=True)
  File "/usr/lib/python2.6/site-packages/dbus/connection.py", line 630, in call_blocking
    message, timeout)
DBusException: org.freedesktop.DBus.Error.NoMemory: Not enough memory

This could also be a threading / locking issue I do not understand , here are some more errors:

Exception in thread AvahiListener:
Traceback (most recent call last):
  File "/usr/lib64/python2.6/threading.py", line 525, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.6/site-packages/shifter/net/avahi_listener.py", line 92, in run
    avahi.PROTO_UNSPEC, self.service_type, 'local', dbus.UInt32(0))),
  File "/usr/lib/python2.6/site-packages/dbus/proxies.py", line 68, in __call__
    return self._proxy_method(*args, **keywords)
  File "/usr/lib/python2.6/site-packages/dbus/proxies.py", line 140, in __call__
    **keywords)
  File "/usr/lib/python2.6/site-packages/dbus/connection.py", line 630, in call_blocking
    message, timeout)
DBusException: org.freedesktop.DBus.Error.NoMemory: Not enough memory

Exception in thread AvahiListener:
Traceback (most recent call last):
  File "/usr/lib64/python2.6/threading.py", line 525, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.6/site-packages/shifter/net/avahi_listener.py", line 81, in run
    self.server = dbus.Interface( self.bus.get_object(avahi.DBUS_NAME, '/'),
  File "/usr/lib/python2.6/site-packages/dbus/bus.py", line 244, in get_object
    follow_name_owner_changes=follow_name_owner_changes)
  File "/usr/lib/python2.6/site-packages/dbus/proxies.py", line 259, in __init__
    self._pending_introspect = self._Introspect()
  File "/usr/lib/python2.6/site-packages/dbus/proxies.py", line 371, in _Introspect
    require_main_loop=False)
  File "/usr/lib/python2.6/site-packages/dbus/connection.py", line 595, in call_async
    require_main_loop=require_main_loop)
MemoryError

Install msjnc application from: ​http://mad-scientist.us/juniper.html

Server running application is Ubuntu 14.04-1.

Application is installed into window-switch menus as "Internet->VPN Session Disconnect". (It's actual name in the system is "Network Connect")

Attempting to run it from Window-Switch results in an xpra session briefly starting, and then closing down. Logs don't seem to match up with anything (I don't see any session logs that mention msjnc, and although I have two xpra processes and a Xvfb-for-Xpra- process left over, claiming to be :67 and :68, my only logs are for other numbers and appear to be prior sessions).

Running the application from the server itself, using:

xpra start ssh:127.0.0.1:100 --start-child=msjnc

is successful.

Apparently the windows xpra client doesn't accept the "--start-child" parameter, so I'm not quite sure how to test it when starting from remote.

The application does not succeed when running from window-switch on the local machine, either.

Printing and sound do not work properly as it is (sound is unreliable and unsafe - printing does not work on win32..) So just disable the options until we sort this out.