Guest-Additions don't work under Host Xubuntu 7.04 AMD64 Guest Kubuntu 7.04 or 7.10 -> fixed in SVN/1.5.0

[Cortexbuster]

I can install Kubuntu 7.04 or Kubuntu 7.10 on a virtual machine. The host system is Xubuntu 7.04 wit latest updates. Everything works fine until I install guest additions with:

sh ./VBoxLinuxAdditions.run

Everything seems to work fine until I reboot. KDE login appears. When I log in KDE goes blank, and the login screen apperas again. Dmesg says:

mtrr: your processor doesn't support write combining

Could this possibly be a hardware error since write combining is disabled in the host's bios? The guest shouldn't see anything of the host's hardware except the CPU, should he? Or is it a software incompatibility?

[Frank Mehnert]

Please attach the /var/log/Xorg.0.log of your guest.

[Cortexbuster]

Client's Xorg.0.log

[Frank Mehnert]

The mtrr message is harmless. It just means that VirtualBox does not emulate MTRRs but they aren't really needed. The last message of your log is interesting, maybe an SELinux issue?

[Michael Thayer]

The last message often occurs when there is a problem with X11 setup (such as with the .Xauthority file - see ​http://forums.macosxhints.com/archive/index.php/t-4142.html). It has also been seen on Ubuntu systems with broken NVidia driver installations - ​http://ubuntuforums.org/showthread.php?t=193670 (I assume that you did not attempt to install an NVidia driver in the virtual machine?) Not sure why installing the guest additions should cause it though.

[Cortexbuster]

The host has a onboard NVidia graphics card, but I didn't install those drivers in the virtual machine. The only thing I did was installing Kubuntu using the Live CD and afterwards installing the guest additions. Nothing more. I'll check on the .Xauthority thing even though it seems kind of strange to me. I already installed both versions (7.04 and 7.10) twice from scratch. The error remains the same.

[oblivion]

I had the exact same problems as reported by Cortexbuster with kubuntu 7.04 as guest. Here's how I fixed it.

After installing the guest additions, open /etc/X11/Xsession.d/98vboxadd-xclient and substitute the last line:

/usr/bin/vboxadd-xclient

with

/usr/bin/vboxadd-xclient || true

vboxadd-xclient is linked against libstdc++.so.5, whereas ubuntu has libstdc++.so.6. Thus, it returns != 0 and prevents further startup of the X session. (The files under /etc/X11/Xsession.d are sourced, not executed!).

[Cortexbuster]

Great :-) Thanks oblivion, after changing that line it finally works.

[Frank Mehnert]

libstdc++-5 / libstdc++-6 actually depends on the version. The guest additions contained in VirtualBox compiled for newer distributions (Ubuntu Feisty, Debian Etch) depend on libstdc++-6, the guest additions in VirtualBox-1.4.0.run depend on libstdc++-5.

[Frank Mehnert]

VirtualBox 1.4.2 will contain a vboxadd-xclient binary statically linked against libstdc++.

[Cortexbuster]

Well, after installing Gutsy once again I encountered another problem: After installing the guest additions kdm doesn't start anymore. After booting I get a console login. I attached another Xorg.0.log

[Frank Mehnert]

This is probably the same problem as with Fedora 7. Please could you try to add

Section "ServerFlags"
    Option      "Xinerama" "true"
EndSection

to /etc/X11/xorg.conf of your guest and reboot the guest again?