isaacs/npm — comment on commit a5bbf487ee27255a97d0ac348b33eb692d2f6130
File:  line 0
By kapouer:

npm should not try to save in builtinconfig file, for example :

npm adduser
Username: (xxx)
Email: (xxx@xxx.xx)
npm ERR! Failed saving /usr/share/npm/npmrc Error: EACCES, Permission denied '/usr/share/npm/npmrc'

Especially when the user is not root.