I want to
Go to a known project in a launchpad branch
Modify a small parameter in the code/configuration
Build the new thing into a ppa
I get most of that, but the < source.changes > in
$ dput ppa:your-lp-id/ppa < source.changes >
hides a lot of work (copy/paste of files/build/test/headaches/...) and a lot of time lost. What's the easiest way to get the same result ?