A friend was running into an error when using node to install a package. When installing the package he was getting the error “npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules”. The fix turned out to be pretty simple and he just needed to take ownership of the node_modules folder.
Open terminal and run this simple snippet to fix the problem:
sudo chown -R $(whoami) /usr/local/lib/node_modules/