This seems like a path to bugs because maven doesn't support this natively. This is better than using the version plugin or something similar? Can we do anything else with this flatten plugin besides populate the version value? Would we need to?

Yeah, it feels a bit ugly to me too, but I'm following the advice that the maven project themselves gave: https://maven.apache.org/maven-ci-friendly.html#install-deploy

It would be great if maven did this work without a plug-in, but if they are saying use flatten in the official docs, who am I to argue?

FWIW, there are a lot of wins for making this change:

• Forks can actually set their own version just by doing mvn -Drevision=(foo)
• The patch between versions is significantly smaller.
• Rebasing old branches is much easier if they have to cross a version boundary.
• The code to actually cut a release is much much easier to maintain.

thanks for the review @ndimiduk !