I debug a simple swift app , it can normally running in the simulator, but on a real machine running on the crash immediately .
system version , ios 8 xcode version , 6.0.1
crash log
dyld: Library not loaded: @rpath/libswiftCore.dylib Referenced from: /private/var/mobile/Containers/Bundle/Application/002E2F03-EE10-433B-B95F-AE3760E777DA/sMdp.app/sMdp Reason: no suitable image found. Did find: /private/var/mobile/Containers/Bundle/Application/002E2F03-EE10-433B-B95F-AE3760E777DA/sMdp.app/Frameworks/libswiftCore.dylib: mmap() error 1 at address=0x100104000, size=0x00194000 segment=__TEXT in Segment::map() mapping /private/var/mobile/Containers/Bundle/Application/002E2F03-EE10-433B-B95F-AE3760E777DA/sMdp.app/Frameworks/libswiftCore.dylib