I have experienced the same problem when trying to publish my nodejs app in a private server running CentOs using root user. The same error is fired by "postinstall": "./node_modules/bower/bin/bower install" in my package.json file so the only solution that was working for me is to use both options to avoid the error:
1: use --allow-root option for bower install command
"postinstall": "./node_modules/bower/bin/bower --allow-root install"
2: use --unsafe-perm option for npm install command
npm install --unsafe-perm