This bug was fixed in the package ubuntu-release-upgrader - 1:18.10.11.5
--------------- ubuntu-release-upgrader (1:18.10.11.5) cosmic; urgency=medium
* Remove lubuntu-core from the list of metapackages, fixing some upgrades from Lubuntu 18.04 to 18.10 (LP: #1799855).
-- Simon Quigley <email address hidden> Fri, 01 Feb 2019 18:52:07 -0600
This bug was fixed in the package ubuntu- release- upgrader - 1:18.10.11.5
--------------- release- upgrader (1:18.10.11.5) cosmic; urgency=medium
ubuntu-
* Remove lubuntu-core from the list of metapackages, fixing some upgrades
from Lubuntu 18.04 to 18.10 (LP: #1799855).
-- Simon Quigley <email address hidden> Fri, 01 Feb 2019 18:52:07 -0600