Thank you for taking the time to report this bug and helping to make Ubuntu better.
From the Log I found:
Use of uninitialized value $reply in scalar chomp at /usr/share/perl5/Debconf/FrontEnd/Passthrough.pm line 66, <GEN0> line 12.
But those should be unrelated. They are part of a very old issue that can't be 100% fixed in all cases but should not be fatal.
It might be useful if you can report the output of journalctl -xe after such a failed upgrade.
Maybe we can find some more what is going on in your case in there.
Since there isn't enough information in your report to differentiate between a local configuration problem and a bug in Ubuntu, I'm marking this bug as Incomplete.
Or if you believe that this is really a bug, then you may find it helpful to read "How to report bugs effectively" http://www.chiark.greenend.org.uk/~sgtatham/bugs.html. We'd be grateful if you would then provide a more complete description of the problem, explain why you believe this is a bug in Ubuntu rather than a problem specific to your system, and then change the bug status back to New.
Thank you for taking the time to report this bug and helping to make Ubuntu better.
From the Log I found: perl5/Debconf/ FrontEnd/ Passthrough. pm line 66, <GEN0> line 12.
Use of uninitialized value $reply in scalar chomp at /usr/share/
But those should be unrelated. They are part of a very old issue that can't be 100% fixed in all cases but should not be fatal.
It might be useful if you can report the output of journalctl -xe after such a failed upgrade.
Maybe we can find some more what is going on in your case in there.
Since there isn't enough information in your report to differentiate between a local configuration problem and a bug in Ubuntu, I'm marking this bug as Incomplete.
If indeed this is a local configuration problem, you can find pointers to get help for this sort of problem here: http:// www.ubuntu. com/support/ community
Or if you believe that this is really a bug, then you may find it helpful to read "How to report bugs effectively" http:// www.chiark. greenend. org.uk/ ~sgtatham/ bugs.html. We'd be grateful if you would then provide a more complete description of the problem, explain why you believe this is a bug in Ubuntu rather than a problem specific to your system, and then change the bug status back to New.