[bbq]

You're right. I think this goal is difficult if not impossible given the way things are.

Missing, I think, is the requirement that open source projects are written with something like Repobuild in mind - consciously choosing to be part of an Open Package Build Network.

It does seem to run counter to open source to standardize around a build system. However, the power unlocked by such a build system (as alluded to in the OP) might be reason to make the move. Who wants to tinker around with the 20 different build systems each of your dependencies uses?

In other words, if the open source world starts moving in the direction of a standard build system, gaining momentum, it seems to follow the open source world can reach further in its endeavors, tackling more and more complex problems.