> rebuild it from scratch

That's beyond the definition of Open Source. Doing a bit of license research now, only the GPL has such a requirement - GPLv3:

> The "Corresponding Source" for a work in object code form means all the source code needed to generate, install, and (for an executable work) run the object code and to modify the work, including scripts to control those activities.

But all other Open Source compliant licenses I checked don't, and just refer to making whatever is in the repo available to others.