Comment 250 for bug 1493888

I hit this today when upgrading from 15.04 to 15.10 on Dell with hybrid graphics. It booted into safe graphics mode, offering a list of graphic operations to try. I didn't touch that and instead ssh'd into the system.

There I looked at /etc/apt/sources.list and saw that wiley-updates was represented.

Next I ran:
  $ sudo apt-get update

Which failed with:
  E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.

So I played along:
  $ sudo dpkg --configure -a

This ran well and stopped to prompt me to replace or keep some ATI related files. I opted for replace in every case by answering "Y".

It installed a bunch of stuff and I saw it compile the fglrx module. After it completed I rebooted with:
  $ sudo shutdown -r now

It rebooted and graphics worked again. glxgears seems happy.

HTH