A couple of things in the x11-common.config script validate_nice_value() don't look right to me:
1) That "set +e ... set -e" seems -really- bogus. That forces exit on non-zero exit status from simple commands, and this script intentionally invokes some simple commands that might exit non-zero, such as the expr line on the very next line after the "set +e". 2) I believe that expr can exit with 3 if asked to subtract non-numbers. So I'd suggest changing the line: if [ $? -ne 2 ]; then to be instead the line: if [ $? -lt 2 ]; then -- x11-common loop asking 'Please enter an integer between -20 and 19.' at debconf medium or higher https://launchpad.net/bugs/68267 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs