Comment 7 for bug 271339

The problem I had was different - it was trying to run /etc/kernel/postinst.d/nvidia-common which in turn uses a Python script called /usr/bin/nvidia-detector which in turn uses a Python module that wasn't there.

I had the following sequence:

- installed new machine from the 8.10 amd 64 beta around Oct 16, which originally came with a 2.6.25 (I think) kernel, which supported the NVidia closed source fglrx driver
- upgraded via Update Manager to 2.6.27-4 which does not support it
- had a problem with non-deb Python modules, so did an rm -rf on /usr/lib/python2.*/site-packages/* and reinstalled Python and its add-ons
- upgraded from 2.6.27-4 to 2.6.27-7, and the postinst cascade-failed due to the nvidia-common

I probably inadvertently killed the Nvidia Python module, and there was no new version to replace it.

In my case, AFAICT the underlying bug is that postinst.d/nvidia-common, /usr/bin/nvidia-detector etc. should have been removed along with the fglrx driver when upgrading to 2.6.27-4 - it wouldn't be seen by a normal user who wasn't dinking with the Python installation.

My workaround was:

sudo chmod 0 /usr/bin/nvidia-common
sudo dpkg --configure -a # re-run the failed postinst