Dear Kai-Heng Feng, I later found that if I unplug one of the four external USB drives the update process runs to completion. Apparently if Ubuntu MATE 18.04 is having problems with an external USB drive, the software upgrade process fails. (It might be crashing when it attempts to access the UEFI functions which walk through every drive - just a guess.)
Robert Pearson -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1800427 Title: sudo apt-get upgrade hangs To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1800427/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs