[winswitch] Xpra on ubuntu 18.04 unity

[Iwan Vosloo]

Hi,

We've been using xpra on Ubuntu 16.04 for a while now without issues, 
(thanks!) but after upgrade to Ubuntu 18.04 we cant get the client to 
work under unity.

We run xpra server inside an lxc container. The container runs Ubuntu 
18.04 (and has done so before the client side has been upgraded without 
issues), and xpra --version says: xpra v2.3.4-r20509

Xpra is started like this:
   xpra start --sharing=yes :100

Then we attach from outside the container, with the same version of xpra:
   xpra attach --sharing=yes ssh:10.0.3.140:100

When run from a normal, "Ubuntu" session (meaning the new Gnome shipped 
with Ubuntu 18.04), all is well.

However, if we log into a unity session (which is what we'd like to do), 
xpra cannot attach,  giving:

2018-10-05 08:35:15,622 Xpra gtk2 client version 2.3.4-r20509 64-bit
2018-10-05 08:35:15,623  running on Linux Ubuntu 18.04 bionic
2018-10-05 08:35:17,212 GStreamer version 1.14.1 for Python 2.7.15 64-bit
2018-10-05 08:35:17,376 No OpenGL_accelerate module loaded: No module 
named OpenGL_accelerate
/usr/lib/python2.7/dist-packages/xpra/client/gl/gtk_base/gtkgl_check.py:152: 
Warning: cannot register existing type 'GdkScreen'
   glarea.realize()
/usr/lib/python2.7/dist-packages/xpra/client/gl/gtk_base/gtkgl_check.py:152: 
Warning: g_once_init_leave: assertion 'result != 0' failed
   glarea.realize()
/usr/lib/python2.7/dist-packages/xpra/client/gl/gtk_base/gtkgl_check.py:152: 
GtkWarning: gdk_screen_is_composited: assertion 'GDK_IS_SCREEN (screen)' 
failed
   glarea.realize()
Segmentation fault (core dumped)

If we run it under unity with:
   xpra attach --sharing=yes --opengl=no ssh:vagrant at 10.0.3.140:100

...then it attaches fine (also according to the server log file), but 
running a program on :100 does not open a window on the attached client.

I have also noticed that if you click on the app indicator that xpra 
client adds to unity, and click on anything (say Information>>Session 
info), nothing is displayed either.

How do I go about debugging this further?

Thanks.

-- 
Iwan