[striking]

Docker also has a cache, making dependency installs not usually an issue.

[Rockslide]

Which works on a totally different level and doesn't help at all in terms of sharing dependency snapshots between different projects.

[striking]

That is not something I'd want to do. Docker's solution is good enough for almost every build that happens. I can eat the time cost not covered by that solution and not have to worry about bugs stemming from improper copying of dep snapshots.