package libgl1-mesa-glx 7.10.2-0ubuntu2.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2

[Klaus Meijners]

Initial error message is:

update-alternatives: error: alternative link /usr/lib/xorg/extra-modules is already managed by x86_64-linux-gnu_gl_conf

ProblemType: Package
DistroRelease: Ubuntu 11.04
Package: libgl1-mesa-glx 7.10.2-0ubuntu2.1
ProcVersionSignature: Ubuntu 3.0.0-9.12-generic 3.0.3
Uname: Linux 3.0.0-9-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
Date: Sun Aug 28 11:03:50 2011
DistUpgraded: Log time: 2011-04-01 20:10:26.612405
DistroCodename: natty
DistroVariant: ubuntu
ErrorMessage: subprocess installed post-installation script returned error exit status 2
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
SourcePackage: mesa
Title: package libgl1-mesa-glx 7.10.2-0ubuntu2.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2
UpgradeStatus: Upgraded to natty on 2011-04-01 (148 days ago)
version.compiz: compiz 1:0.9.4+bzr20110606-0ubuntu1~natty2
version.ia32-libs: ia32-libs 20090808ubuntu13
version.libdrm2: libdrm2 2.4.25-2ubuntu2
version.libgl1-mesa-dri: libgl1-mesa-dri 7.10.2-0ubuntu2.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 7.10.2-0ubuntu2.1
version.xserver-xorg: xserver-xorg 1:7.6+4ubuntu3.1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.2-1ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.14.0-4ubuntu7.2
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110107+b795ca6e-0ubuntu7