GNU make parallell building feature is cool. And ccache which speeds up rebuilds of same files is cool too. But even with this great tools rebuilding some project is still not as fast as it can be. Why ? Because preparing GNU autotools files (./configure & friends) takes quite long time. And there is no way to parallelize it.
But we can cache autotools products just as ccache caches compiler products. And now there is tool that's capable of doing that! You can grab it here. I've adapted fabricate.py for this job.
Just put fabricate.py into PATH and prepend it to your command. Like:
fabricate.py sh -c './bootstrap && ./configure'
And it'll copy command outputs from cache if all dependencies are same. Nearly instantaneous!