npm install email@example.com fails with
npm ERR! Error: ENOENT, open '/Users/shinuza/tmp/node_modules/commander/package.json'
npm install firstname.lastname@example.org works, depending if 0.6.0 is backwards compatible this pull request might be required to install commander (at least the git up version)
NVM, I deleted ~/.npm/commander/, and I don't have this error anymore. Sorry for the noise