Sorry for delayed response. It spends ~1 minute every time in

[shade-zinc]

before it starts actually compiling: https://travis-ci.org/jhump/bluegosling/builds It looks like the actual virtual envs (e.g. pants bootstrapping itself) is properly cached. It has more "bootstrap" steps printed out in travis, but this is the one that takes a while. (On my laptop, it skips all of these and gets right into compiling code in ~1 second.)