I just reinstalled Ubuntu MATE 15.10 from scratch. I had followed this answer to save a list of installed packages and restore it on the newly installed system.
However, when I do
sudo dpkg --set-selections < packages-backup.list
I get a long list of error messages like these:
dpkg: warning: package not in database at line 1417: sqlite3 dpkg: warning: package not in database at line 1417: sqliteman dpkg: warning: package not in database at line 1417: sqliteman-doc
dpkg: warning: found unknown packages; this might mean the available database is outdated, and needs to be updated through a frontend method
So I ran
sudo apt-get update and re-ran
dpkg but I keep getting the same error.
I seem to get this error message for every single package in the list, including rather unspectacular ones such as the default kernel or sqlite. Also, I had not added any additional PPAs on my previous setup, thus packages from non-default repositories can't be the issue here.
As a test, I tried to install one of the "offending" packages with
sudo apt-get install, which worked without any issues.
What's going wrong here?