I had same problem, replaced sources.list with suggested one (xenial instead of bionic) but still unable to upgrade
Reading cache
Checking package manager Reading package lists... Done Building dependency tree Reading state information... Done Hit http://security.ubuntu.com/ubuntu xenial-security InRelease Hit http://us.archive.ubuntu.com/ubuntu xenial InRelease Hit http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease Hit http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease Fetched 0 B in 0s (0 B/s) Reading package lists... Done Building dependency tree Reading state information... Done
Restoring original system state
Aborting Reading package lists... Done Building dependency tree Reading state information... Done === Command detached from window (Fri Jan 25 15:26:39 2019) === === Command terminated with exit status 1 (Fri Jan 25 15:26:49 2019) ===
I had same problem, replaced sources.list with suggested one (xenial instead of bionic) but still unable to upgrade
Reading cache
Checking package manager security. ubuntu. com/ubuntu xenial-security InRelease us.archive. ubuntu. com/ubuntu xenial InRelease us.archive. ubuntu. com/ubuntu xenial-updates InRelease us.archive. ubuntu. com/ubuntu xenial-backports InRelease
Reading package lists... Done
Building dependency tree
Reading state information... Done
Hit http://
Hit http://
Hit http://
Hit http://
Fetched 0 B in 0s (0 B/s)
Reading package lists... Done
Building dependency tree
Reading state information... Done
Restoring original system state
Aborting
Reading package lists... Done
Building dependency tree
Reading state information... Done
=== Command detached from window (Fri Jan 25 15:26:39 2019) ===
=== Command terminated with exit status 1 (Fri Jan 25 15:26:49 2019) ===