Attempting to connect from a Precise client to a Trusty server will fail very, very badly. Apparently there is no backwards compatibility at all. I imagine this is a result of the packages being ancient and the only real hope for those of us on LTS is a backport.
Client:
$ xpra attach ssh:user133@server:700 -z0
connection lost: empty marker in read queue
Connection lost
Server log:
2015-04-17 12:43:57,830 new_connection((1, <socket._socketobject object at 0x7f8c9ca58280>)) sock=<socket._socketobject object at 0x7f8c8f2cb600>, sockname=/home/user133/.xpra/server-700, address=, peername=
2015-04-17 12:43:57,830 New connection received: SocketConnection(/home/user133/.xpra/server-700)
2015-04-17 12:43:57,831 enable_bencode()
2015-04-17 12:43:57,831 io_thread_loop(write, <bound method Protocol._write of <xpra.net.protocol.Protocol object at 0x7f8c8ec2bf90>>) loop starting
2015-04-17 12:43:57,832 io_thread_loop(read, <bound method Protocol._read of <xpra.net.protocol.Protocol object at 0x7f8c8ec2bf90>>) loop starting
2015-04-17 12:43:57,832 read_parse_thread_loop starting
2015-04-17 12:43:57,833 write_format_thread_loop starting
2015-04-17 12:43:59,028 invalid_header(Protocol(SocketConnection(/home/user133/.xpra/server-700)), 'l5:hellod20:__prerelease_version8:0.0.7.364:belli1e9:clipboardi1e7:cursorsi1e15:damage_sequencei1e12'...)
2015-04-17 12:43:59,029 will process ui packet gibberish
2015-04-17 12:43:59,029 Received uninterpretable nonsense: 'l5:hellod20:__prerelease_version8:0.0.7.364:belli1e9:clipboardi1e7:cursorsi1e15:damage_sequencei1e12:desktop_sizeli1024ei768ee19:dynamic_compressioni1e9:encodingsl5:rgb244:jpeg3:pnge4:jpegi80e10:key_repeatli500ei30ee22:keyboard_as_propertiesi1e13:keyboard_synci1e6:keymap234:xkb_keymap {\n\txkb_keycodes { include "evdev+aliases(qwerty)"\t};\n\txkb_types
[snip]
2015-04-17 12:43:59,030 Disconnecting existing client Protocol(SocketConnection(/home/user133/.xpra/server-700)), reason is: invalid packet format, not an xpra client?
2015-04-17 12:43:59,030 flush_then_close: acquired the write lock
2015-04-17 12:43:59,030 flush_then_close: queue is now empty, sending the last packet and closing
2015-04-17 12:43:59,030 Connection lost
2015-04-17 12:43:59,031 close() closed=False
2015-04-17 12:43:59,031 terminate_queue_threads()
2015-04-17 12:43:59,031 will process ui packet connection-lost
2015-04-17 12:43:59,032 io_thread_loop(write, <bound method Protocol._write of <xpra.net.protocol.Protocol object at 0x7f8c8ec2bf90>>) loop ended, closed=True
2015-04-17 12:43:59,033 Connection lost
2015-04-17 12:43:59,034 _clear_keys_pressed()
2015-04-17 12:43:59,034 focus wid=0 has_focus=0
2015-04-17 12:43:59,129 read thread: eof
2015-04-17 12:43:59,129 close() closed=True
2015-04-17 12:43:59,129 io_thread_loop(read, <bound method Protocol._read of <xpra.net.protocol.Protocol object at 0x7f8c8ec2bf90>>) loop ended, closed=True
2015-04-17 12:44:00,031 connection lost: invalid packet header byte: '0x6c', not an xpra client? read buffer=0x'l5:hellod20:__prerelease_version8:0.0.7.364:belli1e9:clipboardi1e7:cursorsi1e15:damage_sequencei1e12'...
2015-04-17 12:44:00,031 close() closed=True
2015-04-17 12:44:04,032 close() closed=True
ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: xpra 0.0.7.36+dfsg-1
ProcVersionSignature: Ubuntu 3.11.0-26.45~precise1-generic 3.11.10.12
Uname: Linux 3.11.0-26-generic i686
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu17.8
Architecture: i386
Date: Fri Apr 17 12:40:53 2015
MarkForUpload: True
ProcEnviron:
LANGUAGE=en_GB:en
TERM=xterm
PATH=(custom, no user)
LANG=en_GB.UTF-8
SHELL=/bin/bash
SourcePackage: xpra
UpgradeStatus: Upgraded to precise on 2014-12-07 (130 days ago)
From Xpra's FAQ at https:/
* Which versions are supported? Which ones are compatible with which versions?
The current release (0.14.x) is compatible with versions going back to v0.7.8. However, just because it is possible to connect does not mean that you should be using an outdated version. Outdated versions contain known bugs and vulnerabilities.
Precise:
$ xpra --version
xpra v0.0.7.36
Trusty:
$ xpra --version
xpra v0.12.3
So Precise is incompatible with all other versions of Ubuntu. A backport will be needed. I will test this later and update with the results.