shopify-app-cli has a public repository, I would create an issue there. When you do, I would recommend describing the nature of the issue more. Do you get any error messages? Is it just hanging? The screen shot doesn't tell me much.
Just taking a wild guess, could it be permissions? Try
sudo eval " $( curl -sS https://raw.githubusercontent.com/Shopify/shopify-app-cli/master/install.sh ) ".