I'm surprised .deb doesn't have a better approach. RPM has epoch for this purpose http://novosial.org/rpm/epoch/index.html
Two reasons:
1. Once you bump the epoch, you have to use it forever. 2. The deb filename often doesn't contain the epoch (we use a colon which isn't valid on many filesystems), so an epoch-revert will give the same file name as pre-epoch, which breaks your repository.
So, the current best practice is the +really+ thing.
And I fail to see why bumping the epoch would ever be a problem. Using the epoch not a reason why its bad.
So now I actually bothered to look it up, and it turns out the actual reason is that the epoch changes what version is considered "greater", but it's not part of the .deb filename, so you still can't reuse version numbers used in the past. If you release 5.0, then 5.1, then you want to rollback and release 1:5.0, it's going to break things in the Debian archives. https://www.debian.org/doc/debian-policy/ch-binary.html#uniq...
Additionally, once you add an epoch you're stuck with it forever, while if you use 5.1+really5.0, you can get rid of the kludge when 5.2 is out. https://www.debian.org/doc/debian-policy/ch-controlfields.ht...
Maybe they’re expecting a 5.6.x release shortly that fixes all these issues & don’t want to add an epoch for a very short term packaging issue?
