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Bug tracker and wiki

Version 41 (modified by Antoine Martin, 6 years ago) (diff)

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FAQ


Page index:


General

  • 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?

wiki/Source

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

Those are far too old. Use a supported version.

  • What is the license?

GPLv2+

Issues - known problems

  • 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)

  • Pasting from the clipboard is slow

Please 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 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/)

Features - How do I…

Please see also wiki/Usage.

  • 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, ie: "dbus-launch xpra start ..." (see dbus-launch for details). This is one of the things that winswitch does for you.

  • 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

Warnings and Messages

  • "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

  • "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

  • "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.

  • "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

OpenGL Issues

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

No, it is optional.

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

Please see Xdummy, for acceleration see virtualgl

  • "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.

  • 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?

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;'

Platforms

  • 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.

  • There is no system tray with gnome shell

Please complain to gnome for breaking things. 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.

  • 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