Happened to me when aptitude (or presumably any other apt package manager) was interrupted by an accidental X restart. No process shown to be using the file with 'fuser -v /var/cache/debconf/config.dat'. Killing the still running but inactive aptitude and dpkg processes did not work. System reboot fixed the problem.
Happened to me when aptitude (or presumably any other apt package manager) was interrupted by an accidental X restart. No process shown to be using the file with 'fuser -v /var/cache/ debconf/ config. dat'. Killing the still running but inactive aptitude and dpkg processes did not work. System reboot fixed the problem.