half/byteI've seen people do absolutely batshit ... stuff in Gemfiles but making a web request to Github to figure out versions of gems to install (For GH pages) must still be one of the all time greats.
I said it before and I'll say it again, making the dependencies definition file executable code was a mistake. True for both ruby and elixir.
You can do extremely cool and convenient things with it and also shoot yourself in the foot an an extremely cool and convenient way.