vagrant@vagrant-ubuntu-trusty-64:/var/www$ npm install
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@^1.0.0 (node_modules/chokidar/node_modules/fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.0.17: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
npm ERR! Linux 3.13.0-107-generic
npm ERR! argv "/usr/bin/nodejs" "/usr/bin/npm" "install"
npm ERR! node v6.9.4
npm ERR! npm  v3.10.10
npm ERR! path /var/www/node_modules/esprima/bin/esparse.js
npm ERR! code ENOENT
npm ERR! errno -2
npm ERR! syscall chmod

npm ERR! enoent ENOENT: no such file or directory, chmod '/var/www/node_modules/esprima/bin/esparse.js'
npm ERR! enoent ENOENT: no such file or directory, chmod '/var/www/node_modules/esprima/bin/esparse.js'
npm ERR! enoent This is most likely not a problem with npm itself
npm ERR! enoent and is related to npm not being able to find a file.
npm ERR! enoent

npm ERR! Please include the following file with any support request:
npm ERR!     /var/www/npm-debug.log