Why the libstdc++.6.0.9.tbd of xcode 7.0 (7A220) does not support arm64 arch?

Question

Why the libstdc++.6.0.9.tbd of xcode 7.0 (7A220) does not support arm64 arch?See the contents of libstdc++.6.0.9.tbd bellow:---archs:           [ armv7, armv7s, arm64 ]platform:        iosinstall-name:    '/usr/lib/libstdc++.6.dylib'current-version: 104.2compatibility-version: 7.0exports:        - archs:           [ armv7, armv7s ]    symbols:         [ __ZN9__gnu_cxx18stdio_sync_filebufIcSt11char_traitsIcEE6xsgetnEPci,                       __ZN9__gnu_cxx18stdio_sync_filebufIcSt11char_traitsIcEE6xsputnEPKci,                       __ZN9__gnu_cxx18stdio_sync_filebufIcSt11char_traitsIcEED0Ev,                       __ZN9__gnu_cxx18stdio_sync_filebufIcSt11char_traitsIcEED1Ev,                       __ZN9__gnu_cxx18stdio_sync_filebufIwSt11char_traitsIwEE6xsgetnEPwi,                       __ZN9__gnu_cxx18stdio_sync_filebufIwSt11char_traitsIwEE6xsputnEPKwi,                       __ZN9__gnu_cxx18stdio_sync_filebufIwSt11char_traitsIwEED0Ev,                       __ZN9__gnu_cxx18stdio_sync_filebufIwSt11char_traitsIwEED1Ev,

kenny DONG · Answer

Finally i find out that the reason is xcode 7.0 could not  properly link third party embeded dynamic framework,the framework has &#x27;Optional &#x27;status and its Deployment Target is bigger than its owner&#x27;s  Deployment Target.But this case did work with xcode 6.4.