username@machine:~/$  npm install npm@3.10.9
npm ERR! Linux 3.13.0-91-generic
npm ERR! argv "/usr/local/bin/node" "/usr/local/bin/npm" "install" "npm@3.10.9"npm ERR! node v7.0.0
npm ERR! npm  v3.10.8
npm ERR! code MODULE_NOT_FOUND

npm ERR! Cannot find module 'internal/fs'npm ERR! npm ERR! If you need help, you may report this error at:
npm ERR!     <https://github.com/npm/npm/issues>

 解决方案：


  1. using "n" I switched back to the node version 6.9.1 n 6.9.1

  2. installed lates npm sudo npm -g install npm@next

  3. switch back to node 7.2.0 n 7.2.0

  4. everything works