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Bug tracker and wiki

This bug tracker and wiki are being discontinued
please use https://github.com/Xpra-org/xpra instead.

Version 90 (modified by Antoine Martin, 2 years ago) (diff)

add some warnings from #2646


Page index:


  • Why this fork?

This fork started in order to provide features needed to work with winswitch and grew from there.

  • Where is the source and repository?


  • How do I contribute?

You can send your patches via this tracker, on the mailing list, or just contact us via irc.

  • Why do you use subversion instead of $my-preferred-DVCS (git or other).

Because it is the right tool for the job. (key point: numeric release numbers beat git hashes for non distributed development)

  • I don't want to install winswitch.

Then don't. xpra and winswitch live in the same repository, that's all.

  • Which version shall I be using?

Please always used the latest released version, you can see the last revision tagged here, or look for the last source release here.

  • I have version 0.3.x or version 0.0.6 installed and I can't connect.

Those are far too old. Use a supported version.

  • Should I use the version shipped with my Linux distribution?

It depends, generally not.

  • Which versions are supported? Which ones are compatible with which versions?

The current LTS 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 However, just because it is possible to connect does not mean that you should be using an outdated version. Outdated versions contain known bugs and vulnerabilities.

  • What is the license?


  • I get a GPG signature warning when I try to install

You probably forgot to import the GPG key before installing the package. The key signature is: c11c 0a4d f702 edf6 c04f 458c 18ad b31c f18a d6bb.

Issues - known problems

Please see also: Application Quirks

  • Xpra cannot start or crashes

Try a different encoding (ie: --encoding=png) and use packaged versions that are known to work, if you build from source you may need to apply some patches to match your specific environment

  • Xpra crashed! Can I recover my session?

Generally yes, as long as the virtual display server (vfb) has not crashed. If the xpra server is completely gone, you can start a new one with "xpra start --use-display" to re-use the existing display. If it is still running but unresponsive, you should kill it first (and use kill -9 to prevent the tear down code from also stopping the vfb display)

  • Why does Xpra use so much of my CPU?

sound forwarding will consume a little bit of CPU and bandwidth. Turn if off if you don't need it. Some applications will also repaint their windows unnecessarily, if you don't use them, try minimizing the window.

  • I have keyboard problems

Please see here: wiki/Keyboard

  • Clipboard does not work or is slow

Please see here: wiki/Clipboard. Make sure that you are not running a clipboard manager which may interfere with xpra's clipboard synchronization code (ie: klipper is known to cause such problems)

  • I use RDP #696 (or x2go #735) and I have problems

As per above, those tools will do their own clipboard synchronization which will definitely cause problems - try disabling one of the clipboard synchronization mechanism, and if possible, do not layer remote desktop protocols on top of each other

  • I cannot click on menus

If you are using Qt/KDE, this is known bug which has been fixed so you will need up to date Qt/KDE libraries, see the platforms section below

  • I cannot use Xpra with NFS home

Use the socket-dir option to place Xpra's log files and sockets in a location that is not NFS mounted (ie: /tmp/)

  • my opengl application refuses to start with virtualgl

Please see #898

  • my applications are missing their menu bar on Ubuntu

Always start your applications with xpra start --start=APP and not DISPLAY=:N APP (see #1419)

Features - How do I…

Please see also Usage.

  • Start gpg-agent, dbus, etc for each session?

Usually, adding this to /etc/xpra/xpra.conf or the per-user ~/.xpra/xpra.conf is enough (version 0.15 onwards):

start = /etc/X11/xinit/Xsession true

(on some distros Xsession is found under /etc/X11/Xsession instead)

Or you may want to add each application individually (one start-child line per application).

  • Use an SSH key with MS Windows clients?

Use pageant: putty FAQ How do I use all PuTTY's features (public keys, proxying, cipher selection, etc.) in PSCP, PSFTP and Plink?

  • How do I use notifications forwarding?

System notifications use dbus, so you must start the xpra server within its own dbus session, see below:

  • How do I start a dbus session for the xpra server?

Xpra should do that automatically, see xpra's --dbus-launch option, otherwise you can also do: dbus-launch xpra start ... (see dbus-launch for details).

  • dbus-launch fails: /bin/sh: 1: dbus-launch: not found

If you do not want a dbus server or do not have one you can run, use: xpra start --dbus-launch=no

  • How can I allow multiple users to connect through a single port?

See wiki/ProxyServer

  • How do I forward a full desktop (ala VNC) instead of individual applications?

See Usage: Forwarding a whole desktop

  • How do I use mmap with different users?

Please see the --mmap-group option: the two users need to be in the same group, the mmap file created by the client will use the group-id of the server socket file. You must generally also use the --socket-dir option to place the socket in a location which is available to both users (ie: /tmp)

  • How do I theme my application?

That depends on the application. GTK2 applications can be themed by setting the GTK2_RC_FILES environment variable, ie:

GTK2_RC_FILES=/path/to/gtkrc YourCommand

See archlinux Xpra server

Warnings and Messages

  • "cannot create group socket '/run/xpra/USERNAME'", usually followed by [Errno 13] Permission denied

Harmless warning, safe to ignore. The server tries to create a socket in the shared group directory /run/xpra. This is only useful for sharing access to sessions via unix group membership, in combination with the socket-permissions option.

  • Failed to rename log file "/run/user/$UID/xpra/Xorg.S$PID.log" to "/run/user/$UID/xpra/Xorg.S$PID.log": No such file or directory

This harmless warning is caused by a bug in your Xorg server, see #1192. Complain to your distribution if this bothers you. This is safe to ignore.

  • "Error: cannot query uinput device path" or "cannot access python uinput module: No module named uinput"

Harmless, safe to ignore. The uinput module is not present or not loaded. This can be used as an alternative to xtest. (for details see ticket:173#comment:24)

  • "cannot use uinput for virtual devices" - harmless, safe to ignore.
  • "cannot access python uinput module: name 'ABS_MAX' is not defined" - your python-uinput package is broken, complain to your distributor
  • "Failed to open the uinput device: Permission denied" - you do not have the permissions required for opening the /dev/uinput device (usually requires root), safe to ignore if you do not want to use uinput devices
  • "no 'numpy' module, HyBi protocol will be slower" - starting with version 2.4, this warning is completely bogus and can be ignored (see ticket:1926#comment:1)
  • "cannot find a valid pkg-config package for ['x264', 'libx264']"

You must either install the x264 development headers (recommended) or compile with the option: "--without-enc_x264"

  • "connection lost: invalid packet header, not an xpra client?"

This is often caused by out of date clients.

  • "Message: pygobject_register_sinkfunc is deprecated (GstObject)"

This harmless warning comes from your distribution's python-gstreamer build, sadly it cannot be avoided.

  • "Xlib: extension "RANDR" missing on display" and "Randr not supported: X server does not support required extension Randr"

The virtual framebuffer (typically Xvfb) does not support Randr, this may cause some display problems, try using Xdummy instead

  • "loop nesting too deep" and "you may have a clipboard forwarding loop, disabling the clipboard"

another piece of software is trying to synchronize the clipboard contents (maybe a clipboard manager, or a virtualization solution like vmware or virtualbox) and this is conflicting with xpra's own mechanism, so xpra stops trying to fight with it - you should disable the other clipboard synchronization if you want xpra clipboard sharing

  • "found an existing window manager on screen ..."

Xpra is a window manager, you cannot run two window managers on the same display at the same time. If you want to forward a whole desktop, including its window manager, see Usage: forwarding a whole desktop, otherwise stop the other window manager.

  • "cannot register our notification forwarder ..."

The xpra server was started from a GUI session which already had a dbus instance and a notification daemon, notifications forwarding will not work. See "How do I use notifications forwarding" (above)

  • "re-starting speaker because of overrun"

This usually means that there is too much network jitter and that sound packets are arriving in bursts. You can try a different sound codec (--speaker-codec option) or just turn off sound if you don't need it. More info here: wiki/Sound

  • "Warning: pulseaudio has terminated. Either fix the pulseaudio command line or use --no-pulseaudio to avoid this warning."

This usually occurs when an xpra session is started from a running X11 session which already has its own pulseaudio server running. Pulseaudio does not support multiple servers per user.

  • "Uh-oh, our size doesn't fit window sizing constraints .."

This means that xpra failed to create a window matching the desired constraints, you may experience display artifacts around the window's borders

  • "dec_avcodec is probably leaking memory"

Your installation should be using dec_avcodec2 (for ffmpeg version 2 onwards) or it is missing some patches

  • "Xorg is not readable"

Your distribution ships Xorg suid but it is not readable by your current user, since Xpra needs to run Xorg non-suid, it needs to make a non-suid copy of the file so you will have to make it readable (please complain to your distributor - there is nothing we can do about this and the security benefits of preventing read access to a suid binary are dubious at best in most cases).
For more details, see Xdummy.

  • "{{{DPI set to NN x NN (wanted MM x MM), you may experience scaling problems, such as huge or small fonts, etc - to fix this issue, try the dpi switch, or use a patched Xorg dummy driver"

You need to install the patched dummy driver which is available in the xpra repositories. More information here: Xdummy

  • "xpra [errno 2] no such file or directory" when connecting via ssh.

Xpra is not installed on the remote host.

  • SSH connection error "The system cannot find the file specified":
    Error running ssh program \
        '['ssh', '-T', 'HOSTNAME', '.xpra/run-xpra', '_proxy', ':10']': \
        [Error 2] The system cannot find the file specified

This means that the user you login as on the server has never had an xpra server running. You must be using the wrong username or even the wrong server. Try adding the username to your ssh connection string:

xpra attach ssh://username@host/
  • I get a GPG error: KEYEXPIRED 1273837137

The key had expired. Try re-importing the updated key. On Debian you may have to delete the key (apt-key -d) before adding it again.

  • During installation I see warnings like these:
    chcon: can't apply partial context to unlabeled file

If you have disabled SELinux you can ignore those warnings, otherwise you may need to relabel your filesystem and ensure that the xpra codecs mentioned in those warnings are labelled correctly to prevent runtime codec failures: chcon -t texrel_shlib_t CODECFILE

  • Warning: xpra server does not support initenv

Your server is out of date, upgrade it. This may cause remote ssh start to fail.

  • X11 keyboard warnings:
    Unsupported high keycode 372 for name <I372> ignored
    X11 cannot support keycodes above 255.
    This warning only shows for the first high keycode.

These are harmless and unavoidable, see Bug 1615700 - warning shows up after run "Xvfb :99 &"

  • gtk_window_add_accel_group: assertion 'GTK_IS_WINDOW (window)' failed - harmless and unavoidable on macos
  • gui.py: Warning: invalid cast from 'GtkMenuBar?' to 'GtkWindow?' - harmless and unavoidable on macos

OpenGL Issues

  • Do I need to have OpenGL enabled on the client?

No, it is optional but strongly recommended in order to achieve good performance.

  • No module named gdkgl

Install gtkglext and its Python bindings to enable support for OpenGL.

  • How do I enable OpenGL or other X11 extensions on the server?

Please see Xdummy, for acceleration see virtualgl, usually just need to run vglrun YOURAPP from within the xpra session.

  • "No OpenGL_accelerate module loaded"

You can install the required module: OpenGL_accelerate or you can ignore this warning, it only means that some OpenGL operations will not be fully accelerated. (Note, if you install python-opengl via distro package manager, e.g. apt, you should not install OpenGL_accelerate directly using pip. That would likely install the latest version which may well be incompatible with PyOpenGL installed via package manager. Rather, you should go to OpenGL_accelerate website and download the version that is the same with your python-opengl package and install it manually!)

  • I get some OpenGL related warnings/errors at runtime:
    ImportError: cannot import name GL
    Unable to load registered array format handler numeric
    Unable to load registered array format handler vbo
    Unable to load registered array format handler vbooffset

These warnings can safely be ignored. It means that your python OpenGL installation is incomplete, either install the missing modules (usually python-numeric) or if you are building from source, you can apply the silence-pyopengl-formathandler-warnings.patch patch to silence those warnings.

  • I get errors like these:
    No module named Numeric
    No module named numpy

This is the same issue as the one above, same answer.

  • Why don't you fix those OpenGL warnings/errors? Or silence warnings by default?

Version 0.12 does. Note: this is a packaging issue (see redhat bugzilla, debian bug), and those are not our packages. Silencing warnings by default is bad practice, some of those messages may well be legitimate. The developers/packagers should remove those that are not. Importing a library should not show ugly warnings on screen, especially when the missing libraries it complains about are deprecated and not available for installation. You can see this for yourself with:

python -c 'import logging; logging.basicConfig(); \
logging.root.setLevel(logging.INFO); \
import OpenGL; from OpenGL.GL import GL_VERSION, GL_EXTENSIONS;'

For Ubuntu Xenial, see #1758.

System Tray

  • There is no system tray with Ubuntu.

There is. Just don't use the packages shipped by Ubuntu, which are outdated and lack the necessary dependencies.

  • There is no system tray with gnome shell

Please complain to gnome for breaking things, they removed the system tray, see #476. There are extensions you can use to restore the system tray area (topicons is one). With v0.11 onwards, you can still access the session information window using the Meta+Shift+F11 shortcut.

  • There is no system tray with KDE5

Just like gnome3, KDE decided to break things, see #1016.


  • Does Xpra work with Windows, Mac OS X, Android?

Some platforms have known limitations: more limited clipboard support on Windows and Mac OS X, no soft keyboard input on Android, etc. If you find a bug or missing feature, please do let us know.

  • I use Xpra.exe but there is no output

Use Xpra_cmd.exe to get output in your DOS window, Xpra.exe redirects all output to its log file Xpra.log.

  • Some applications crash or do not start at all.

This can either be a bug in xpra or some application configuration issue. For example see #435: gnome-terminal may need --disable-factory. Bugs can be fixed, misbehaving applications.. not so much.

  • My application menus are missing on Ubuntu

This breakage was caused by Ubuntu's global menus hack, start your applications with UBUNTU_MENUPROXY set to an empty string to disable this mess (ie: UBUNTU_MENUPROXY="" yourapplication )

  • Does this work with KDE?

Yes. There were problems with some versions of KDE/oxygen (older versions simply crashed, some newer versions prevented clicks from propagating to xpra