The OpenSees Community

I am a new MAC user, I have done the steps as you stated and it worked for me, just the first step was different, i am writing here, it might help other users as well:
Open xcode, from menu go to Open Developer tool, select More Developer Tools..., safari will pop up and you should sign in with your apple account to the apple's developer website, after singed in from the list find Command line tools, download it and install it. then follow the same steps as stated before.
I hope it helps