As a newcomer learning how rebuild works, this would be extremely helpful! The dialogs printed during rebuild could also be clearer - for instance, specifying that it is listing all the dependencies and then working from the top level down to actually build them. Bonus points: a not-entirely-wrong progress bar.

There is no progress bar. There is just a character that appears every few seconds. The build system has no way of knowing that afw will take forever but skymap will take less than 10 seconds.

Also, -u is a bit of a convenience for Jenkins. In most cases you should be doing a git pull to update your repos.yaml.

Changed team to Architecture. As of today the output is:

% rebuild --help

Usage: /Users/timj/work/lsstsw3/bin/rebuild [-p] [-n] [-u] [-r <ref> [-r <ref2> [...]]] [-t <eupstag>] [product1 [product2 [...]]]