Google "yarn plug and play", rather than "yarn zero installs". There isn't much in the way of details outside of the main Yarn website -- now focussed on Yarn 2

Google "yarn plug and play", rather than "yarn zero installs". There isn't much in the way of details outside of the main Yarn website -- now focussed on Yarn 2 -- which has the documentation (vs Yarn 1.n, which does not have plug and play and works the same as NPM, and has now moved to classic.yarnpkg.com) (Edit: I'm not quite sure how this would have completely prevented the issue? P'n'p is very good and seems to be a real step forward for JS package management but surely the same issue could have occurred regardless?)