vncserver, krfb broken with kde 4.2, Intrepid (critical)

[DougR]

Binary package hint: kdebase

After upgrading to kde 4.2, vncserver stopped working. This is a critical bug in my workplace, were we rely heavily on vnc.

Krfb also does not work. I can initiate a vncserver connection in response to a krfb invitation, but the vncviewer display is fuzzy, with double letters for all text. Clicking in the vncviewer window causes multi-colored screen corruption which makse the window completely unviewable.

This bug has been replication on two hosts:
Kubuntu 8.10 X86_64, KDE 4.2, and an identically-configured 32-bit host.

roberts@lilly:~/.vnc$ uname -a
Linux lilly 2.6.27-11-generic #1 SMP Thu Jan 29 19:24:39 UTC 2009 i686 GNU/Linux

Here is my xstartup file:
roberts@lilly:~/.vnc$ more xstartup
#!/bin/sh

# Uncomment the following two lines for normal desktop:
# unset SESSION_MANAGER
# exec /etc/X11/xinit/xinitrc

#[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
#[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
#xsetroot -solid grey
#vncconfig -iconic &
#xterm -geometry 80x2

Here is the vncserver log:

roberts@lilly:~/.vnc$ more /home/roberts/.vnc/lilly:1.log
Couldn't open RGB_DB '/etc/X11/rgb'

Xvnc Free Edition 4.1.1
Copyright (C) 2002-2005 RealVNC Ltd.
See http://www.realvnc.com for information on VNC.
Underlying X server release 70000000, The X.Org Foundation

Tue Mar 10 13:12:38 2009
 vncext: VNC extension running!
 vncext: Listening for VNC connections on port 5901
 vncext: created VNC server for screen 0
error opening security policy file /etc/X11/xserver/SecurityPolicy
Could not init font path element /usr/share/fonts/X11/TTF/, removing from lis
t!
Could not init font path element /usr/share/fonts/X11/OTF, removing from list
!
Could not init font path element /usr/share/fonts/X11/CID/, removing from lis
t!
kdostartupconfig4(18674) main: Running kdostartupconfig.
startkde: Starting up...
kdeinit4: preparing to launch /usr/lib/kde4/libexec/klauncher
klauncher(18696) kdemain: Waiting for already running klauncher to exit.
klauncher(18696) kdemain: Waiting for already running klauncher to exit.
klauncher(18696) kdemain: Another instance of klauncher is already running!
kdeinit4: Communication error with launcher. Exiting!
kdeinit4_wrapper: Warning: connect(/home/roberts/.kde/socket-lilly/kdeinit4__
1) failed: : Connection refused
Could not register with D-BUS. Aborting.
startkde: Shutting down...
kdeinit4_wrapper: Warning: connect(/home/roberts/.kde/socket-lilly/kdeinit4__
1) failed: : Connection refused
Error: Can not contact kdeinit4!
startkde: Running shutdown scripts...
startkde: Done.

[DougR (doug-parrot-farm)]

Folks,

Has anybody reviewed this yet? My group at work relies heavily on vnc, and this bug will prevent us from upgrading until vncserver works with Intrepid and beyond, and KDE4. I've seen lots of chatter on the various lists about this problem, but no activity as of yet on the buglist here.

Thanks,

--Doug

[Jesse Ruffin (joruffin)]

I have the graphical corruption mentioned above, but I am using current intrepid packages on both the client and server. Client and server are managed by the KRFB (server) and KRDC (client), both on Kubuntu 8.10. The server is an AMD64 with an embedded sis chipset and the client is x86 with an embedded Intel 865, fwiw. Connection medium is WiFi, and the problem happens with and without vpn transit. Desktop effects are not enabled on either side. Attached is a screenshot produced by krdc's copy to clipboard.

I realize that this report is different than the poster, so feel free to kick the graphics problem to another bug.

[DougR (doug-parrot-farm)]

I reported the original bug report, and it was actually two manifestations of vncserver breakage:

1) vncserver does not work with 8.10/KDE4.2, and
2) krfb (which uses vnc) is broken. FYI, the type of corrupted client-side view I am experiencing with krfb is identical to the previous poster's.

[Jesse Ruffin (joruffin)]

After some additional testing, I have had success with x11vnc as server and krdc as client, so I suspect that the problem lies in the KRFB server and not in the client.

[DougR (doug-parrot-farm)]

Thanks, I'll give that a try.

BTW, I'm a bit disappointed that none of the Ubuntu support people have seemed to take much of an interest in this particular bug. VNC is an essential part of our daily use of Linux in my office. Lack of a working vncserver in Jaunty will force us to delay upgrading.

[DougR (doug-parrot-farm)]

I also did some testing with x11vnc, and it does work with vnc4viewer as well, so at least there is a work-around to vncserver being broken. Thanks for the tip.

[Rob Buels (rmb32)]

I can confirm the client-side corruption problem with krfb in kubuntu jaunty. I installed vino and ran it just with /usr/lib/vino/vino-server, and it worked just fine. x11vnc also worked fine.

[H.i.M (hir-i-mogul-gmail)]

This Bug exists almost a half year (in KDE4.1.x and KDE4.2.x).
In KDE 4.1 just one statical picture and in KDE 4.2.2 collour corruption.
KRFB is useless without VNC-Server-functionality.
Please fix it now!

[Andrew (andrewk8)]

Me, too. This is possibly a duplicate of bug # 359610, which was filed against krfb 4:4.2.0-0ubuntu1~intrepid.

[Bigleon (bigleon1)]

I just wanted to Confirm that x11vnc is a valid solution to the bug of the Default KDE remote desktop software. It works like a charm and configuration is simple and easy.

[Andrew (andrewk8)]

I added KDE4.3 to Ubuntu 9.04 x86(from the Launchpad kubuntu-ppa repository). krfb 4.3.0-0ubuntu1~jaunty~ppa1 still shows a scrambled screen on a VNC client.

Back to GNOME since I need remote display of the :0 desktop - at least Vino works (when Compiz is disabled).

[DougR (doug-parrot-farm)]

My advice is to switch to the FreeNX client/server: http://freenx.berlios.de/

It works, well, with (K)Ubuntu, with none of the problems that have been reported with vnc4server. The vncserver issues have persisted for months, with no promise of resolution. FreeNX, on the other hand, just works.

[komputes (komputes)]

I can also confirm this krfb bug with the offset colours and artifacts when attempting to control a remote computer.

It has been reported upstream: https://bugs.kde.org/show_bug.cgi?id=162493

[Kevin Christmas (kachristmas)]

A comment on the KDE bug report suggests disabling XDamage and XShm when compiling krfb.

https://bugs.kde.org/show_bug.cgi?id=162493#c64

[Jonathan Thomas (echidnaman)]

Fix committed upstream for KDE 4.3.2.

[Khem Raj (khem-raj)]

will karmic have KDE 4.3.2 ?
when will we see this fix in kubuntu

[Jonathan Thomas (echidnaman)]

KDE 4.3.2 is being released today. Updates can be expected in Kubuntu 9.10 within the next few hours.

[Tiedemate (bjoerntiedemann)]

krfb is still not working on Karmic with KDE4.3.3