I just recently downloaded Xcode 6 beta 4, and my swift project compiles with no errors but before it gets to my code I get a dyld_fatal_error just above start in the call s
I also faced the same issue and tried all the solution given above without any luck.
then what I have done to resolve that I really don’t have much I idea about. So there is Certificated called “apple worldwide developer relations certificate authority” in System group in keychain Access and due to some profile and certificate issue I randomly mark this certificate “Always trusted” from “Use System Defaults”. So this is causing this “dyld_fatal_error” crash to me. when I revert it back to “Use System Defaults” crash got resolved.
So guys if you are tried all the possible option to resolve this crash and didn’t succeed yet, try this also. It helped me, may help you as well.
Found this about this certificate.