I have the same problem but on Windows.

I don't want to post on a necroed thread but yes, Spine is awesome. I ended up purchasing Spine because Spriter pro was taking forever with the mesh tools and even AnimeEffects( free program) has mesh tools! But I needed something that allowed me to do several animation sets and Spine was the answer. Spine is really easy to pick up once you get the basics and the updates are faster!