This is something I really want to explore more through less-compatible modes. It was the original way yarn worked, but it wasn't compatible enough to be the default mode: https://github.com/yarnpkg/yarn/issues/57

If you do, would love see experiments on that. I do wish NPM would start adding badges or some other meta data to packages that signify that a module has constraints like: - No native code - No module state (No multiple singletons, and easily load variants of a module) - Pure installation, aka no build steps and is fully cacheable via hashing/immutable module patterns - Is all pure functional - 100% code coverage - Etc.

Hmm.. is it still available as a configuration option somewhere? I couldn't find it on the site.

I'm a huge fan of bundler - it's dependency heaven. I'm also a big fan of the rubygems repo. It does not allow changes in released versions.

Even without symlinks it's a much needed improvement in the javascript ecosystem

This is something I hope to work on over the next few months. It's a priority for Ember :)

Yeah, that would be much better. But unfortunately the node_modules structure (which yarn is attempting to be fully compatible with) makes that impossible.

The reason is that each package only finds its dependencies relative to its own location. So your second level dependencies cannot vary from project to project unless you do copying.

(Example: AppA and AppB depend on LibX. LibX depends on LibY. Through their deterministic lockfiles, AppA and AppB disagree on which version of LibY to use. There is no way to symlink things together to satisfy that case without copying LibX or altering node's package resolution algorithm.)

You can make it work with `node --preserve-symlinks`

Thanks, I was not aware of that option.

Looks like it's new in Node 6. Yarn supports Node LTS.