Coercing DéjàDup to run a full backup

A while back I started using a Librem 13 laptop running PureOS which is derived from Debian Linux. It has a built-in backup program called DéjàDup which "really just a clever graphical wrapper around the command line backup tool duplicity." It runs incremental backups daily and will "occasionally make fresh full backups for you". The documentation is crap (as of 2021-Feb) so there's no way to make it do such a backup on-demand.

One issue I have discovered is that its incremental backup only looks at the file times (presumably the modified time) to determine which files are new. Ordinarily this is no problem, but I recently migrated thousands of files from my old computer and maintaned the dates. As such, DéjàDup just ignored them. I needed to get it to do a fresh backup.

I found a note on the developer site which suggested editing the settings manually "(dconf-editor or the gsettings command line might work)". I dug around with using gsettings and found the following things that might help:

CommandNotes
gsettings list-recursively org.gnome.DejaDupLists all the settings for DejaDup.
gsettings get org.gnome.DejaDup full-backup-periodDisplays the current number of days between "fresh full bakcups".
gsettings set org.gnome.DejaDup full-backup-period 1Sets the number of days between "fresh full bakcups" to 1 day.

What I did was to close Gnome Backups (the front-end name for DéjàDup) then execute:

gsettings set org.gnome.DejaDup full-backup-period 1

I then launched Gnome Backups again and started a backup. It fortunately said it was doing a full backup. I immediately reset it on the command line but it changed behavior and did an incremental backup instead so I had to wait until it finished, then went to the command line again and reset it, this time a little shorter than the default:

gsettings set org.gnome.DejaDup full-backup-period 60

This seemed to do what I wanted.