It seems Xcode is passive-aggressively encouraging me to switch to Swift 3.0. As I type code, and when I invoke a build, all kinds of warnings & errors relating to Swift 3.0 syntax show up, only to disappear once compilation finishes.
It seems the dynamic incremental compilation setting on the "left hand" is not talking to the static actual compilation setting on the "right hand".
It's very distracting. This is Xcode GM 8.1. Has anyone else experienced this and found a workaround?