mac 安装polymer cli Error: EACCES: permission denied, mkdir '/usr/local/lib/node_modules/polymer-cli/node_modules/wd/build'

安装的时候根据说明，需要使用

npm install -g polymer-cli命令，但是一直提示没有权限，

后来增加sudo后提示如下，

Error: EACCES: permission denied, mkdir '/usr/local/lib/node_modules/polymer-cli/node_modules/wd/build'

at Object.fs.mkdirSync (fs.js:905:18)

at sync (/usr/local/lib/node_modules/polymer-cli/node_modules/mkdirp/index.js:71:13)

at Object.<anonymous> (/usr/local/lib/node_modules/polymer-cli/node_modules/wd/scripts/build-browser-scripts.js:6:1)

at Module._compile (module.js:660:30)

at Object.Module._extensions..js (module.js:671:10)

at Module.load (module.js:573:32)

at tryModuleLoad (module.js:513:12)

at Function.Module._load (module.js:505:3)

at Function.Module.runMain (module.js:701:10)

at startup (bootstrap_node.js:194:16)

npm ERR! code ELIFECYCLE

npm ERR! errno 1

npm ERR! wd@1.5.0 install: `node scripts/build-browser-scripts`

npm ERR! Exit status 1

npm ERR!

npm ERR! Failed at the wd@1.5.0 install script.

npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

查看资料发现，可能需要增加--unsafe-perm，即

sudo npm install --unsafe-perm -g polymer-cli

结果成功了