--exit-with-children option seems to be currently broken:
$ xpra --start-child=xterm --exit-with-children start ssh:aimlin:11 2018-04-16 17:52:40,463 Xpra gtk2 client version 2.2.6-r19015 64-bit 2018-04-16 17:52:40,463 running on Linux Debian stable-updates sid 2018-04-16 17:52:42,138 GStreamer version 1.14.0 for Python 2.7.14 64-bit 2018-04-16 17:52:42,454 No OpenGL_accelerate module loaded: No module named OpenGL_accelerate 2018-04-16 17:52:42,620 OpenGL enabled with Mesa DRI Intel(R) Haswell 2018-04-16 17:52:42,630 failed to instantiate the dbus notification handler: 2018-04-16 17:52:42,630 you may need to start a notification service for 'org.freedesktop.Notifications' 2018-04-16 17:52:42,630 disable notifications to avoid this warning 2018-04-16 17:52:42,647 keyboard settings: rules=evdev, model=pc105, layout=fr 2018-04-16 17:52:42,648 desktop size is 1920x1080 with 1 screen: 2018-04-16 17:52:42,648 :0.0 (508x285 mm - DPI: 96x96) workarea: 1920x1020 at 0x60 2018-04-16 17:52:42,648 monitor 1 (480x270 mm - DPI: 101x101) 2018-04-16 17:52:43,250 Error: cannot watch for video device changes without pyinotify: 2018-04-16 17:52:43,250 No module named pyinotify 2018-04-16 17:52:44,249 xpra initialization error: 2018-04-16 17:52:44,249 --exit-with-children option does not take a value 2018-04-16 17:52:44,250 Error: printing disabled: 2018-04-16 17:52:44,250 No module named cups 2018-04-16 17:52:44,257 Connection lost
Notice I did not give a value to the option. The command succeeds if I remove the option entirely.
Xpra gtk2 client version 2.2.6-r19015 64-bit
running on Linux Debian stable-updates sid
My guess is that your server is quite a bit older than that. Please try r19024. There might be other command line options which need to be handled in a more backwards compatible manner, but I don't have the time to figure out which ones.
I think I somehow fumbled my testing, indeed. I re-tested and it works. Sorry for the noise.
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/1810