Dear lazyweb - when I try out a distribution converted to DistZilla I often discover that I don't have all the plugins used there. Starting the work then consists of a string of 'dzil build' commands, searching the monstrous error stacks for the name of the missing plugin and then running cpan with it. Sure that should be automated!
And, by the way, it could also install the distribution's prerequisites.
Update: Repeating one of the comments - apparently the latest Dist::Zilla supports following solution dzil authordeps | cpanm.