Upon opening the launcher, the application icon appears in the dock for a second, then immediately disappears. The application refuses to open. 

With internet disabled, the launcher loads properly. Reconnecting the internet (with the launcher already loaded) gives me a notification that there's a new launcher version available, and tells me to restart the launcher to update - Which sends me back to square one, launcher quitting immediately.

Also tried deleting the profiles file in ~/minecraft, but no good.