Myles Borins (@thealphanerd) recently ran citgm with yarn, and shared the results. It was 25 minutes faster than npm, but 20 modules failed to install. Yarn is not a drop in replacement.

Some areas where issues arise:

  • Reliance on npm-shrinkwrap.json
  • Private modules on npm
  • Modules backed by self-signed certificates
  • Exotic dependencies declarations like .zip or shorthand urls
  • Edge case issues on specific OSes, like Windows
  • Pre- and post-script hooks don’t work like they do in npm
  • Scripts that rely on npm environmental variables