All I can find is Is there a quick way to force a crash? which says to:
[[Crashlytics sharedInstance] crash];
which I think in Swift would be
but this does not seem to exist. (perhaps the docs are out of date and no longer apply since Fabric gobbled up Crashlytics?)
I see that there is a Crashlytics.crash(self:Crashlytics) …nevermind, friggin XCode's completion is always broken for me. See answer below.