You can however run a command with sudo using “–allow-root” option

执行bower命令后出现以下错误提示：

bower ESUDO         Cannot be run with sudo


Additional error details:
Since bower is a user command, there is no need to execute it with superuser permissions.
If you're having permission errors when using bower without sudo, please spend a few minutes learning more about how your system should work and make any necessary repairs.

http://www.joyent.com/blog/installing-node-and-npm
https://gist.github.com/isaacs/579814

You can however run a command with sudo using --allow-root option

{"allow_root": true }