Npm install failed “cannot run in wd”

使用npm install时，出现了 “cannot run in wd”等字样时，是安装出错了。

需要加上–unsafe-perm参数，完整如下：

npm install --unsafe-perm

或是在package.json中添加：

"config": {
    "unsafe-perm":true
}

官方的解释为：

If npm was invoked with root privileges, then it will change the uid to the user account or uid specified by the user config, which defaults to nobody. Set the unsafe-perm flag to run scripts with root privileges.