I used to be in the Ruby / Rails / Bundler camp, and this was indeed an annoyance. But with Node.js, the typical deployment scenario for us, and I believe othe

I used to be in the Ruby / Rails / Bundler camp, and this was indeed an annoyance. But with Node.js, the typical deployment scenario for us, and I believe others as well, is to simply tar up the entire app including dependencies. I'm not sure if this is possible with the other scripting languages you mention. I also don't believe this is as big an issue in development for Node.js, because most packages are pure-JS, and don't run any build steps whatsoever. Finally, I think it's also very convenient to have my dependencies' sources available in development. I trace into them quite often.