After upgrading Xcode from 6.0 to 6.3, I noticed my automated tests started failing.
2015-04-14 18:56:50.625 xctest[48304:517820] *** Terminating app due to
Following the developer forums, this appears to be a bug or oversight in the developer tools that introduced an incompatibility with binaries built with older versions of the tools.
Should be fixed in Xcode 6.4