Looks like the real culprit here is having casper depend upon ubiquity. I suspect before the removal of udeb packages (including localechooser-data which was the alternative to the depend otherwise satisfied by ubiquity), we never ran into this problem simply because of localechooser-data: https://bugs.launchpad.net/ubuntu/+source/preseed/+bug/1923833
Looks like the real culprit here is having casper depend upon ubiquity. I suspect before the removal of udeb packages (including localechooser-data which was the alternative to the depend otherwise satisfied by ubiquity), we never ran into this problem simply because of localechooser-data: /bugs.launchpad .net/ubuntu/ +source/ preseed/ +bug/1923833
https:/