This is an FYI - I didn’t see anywhere to submit bug reports…
I just installed Xcode 7 (7A220) and when launching ST3 (3083) I received this alert:
https://io_infinit_links.storage.googleapis.com/55f9c7cc9f7c8107d424207a/Screen%20Shot%202015-09-16%20at%203.49.26%20PM.png?GoogleAccessId=798530033299-s9b7qmrc99trk8uid53giuvus1o74cif%40developer.gserviceaccount.com&Expires=1442519602&Signature=XEOLDXzwji3qy4tpfnJpWVzKZGtCN36Y1QtlspcguttY1hAM0Y7Q8VOb%2FDyxK9DMUnygzKo9Sy8c44iXS%2BBjN1ajFK7S8I7WGteAfCfZcJ1XO3Lp66z1iLKNVSa9iDQYuYtyRkIgQu6iBF0JdxEDlk0CVz6TASJskGKV%2BO4yvlE%3D
I had to run Xcode 7, and accept the new license terms, then everything was a-ok 
Not sure which package caused this, but I don’t have any Xcode-specific packages.