Mac OSX，安装 NPM 过程中报错

npm ERR! Darwin 15.6.0
npm ERR! argv "/usr/local/bin/node" "/usr/local/bin/npm" "install" "-g" "cnpm" "--registry=https://registry.npm.taobao.org"
npm ERR! node v6.10.0
npm ERR! npm  v3.10.10
npm ERR! path /usr/local/lib/node_modules
npm ERR! code EACCES
npm ERR! errno -13
npm ERR! syscall access

npm ERR! Error: EACCES: permission denied, access '/usr/local/lib/node_modules'
npm ERR!     at Error (native)
npm ERR!  { Error: EACCES: permission denied, access '/usr/local/lib/node_modules'
npm ERR!     at Error (native)
npm ERR!   errno: -13,
npm ERR!   code: 'EACCES',
npm ERR!   syscall: 'access',
npm ERR!   path: '/usr/local/lib/node_modules' }
npm ERR! 
npm ERR! Please try running this command again as root/Administrator.

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

解决方法：如下
命令行下执行： sudo npm install -g cnpm --registry=https://registry.npm.taobao.org