[winswitch] xpra: unable to start sessions

[Antoine Martin]

> I'm having a lot of trouble trying to start xpra sessions over an ssh
> connection. The attached file gives some details. This has only started
> to be a problem recently, I think since xpra 2.3 was installed on the
> server. Is there an incompatibility between v2.2.6 and v2.3?
No, see:
https://www.xpra.org/trac/wiki/Versions#Compatibility

> $ xpra start ssh/whirligig/100 --start=gnome-terminal &
I believe I saw it fail once, but I have been unable to reproduce the
problem since.

> but attempts to attach to these also failed.
Please always include the full command lines used and their output.

Your sample log also includes output from previously backgrounded
commands, which makes things more difficult to follow.

> Any suggestions welcome.
I would try to get the basics working first, without using remote start:
* directly on the "whirligig" server:
xpra start :100 --start=xterm
* verify the session is accessible:
xpra info :100
* then connect from the client:
xpra attach ssh://whirligig/100

If that works, then you can try the all-in-one:
xpra start ssh://whirligig/100 --start=xterm

And maybe you will need to add --start-via-proxy=no.
It should fallback to not using the proxy if it cannot be reached.

In your outout, I see:
(..) xpra proxy :14500 --daemon=no --bind-tcp=0.0.0.0:14500 ...
So you have a proxy server running. But I'm not sure how you got it
running in the first place since there seems to be a systemd packaging
bug in the Ubuntu 16.04 packages.

Cheers
Antoine