where can i find the libsystem_symptoms.dylib in xcode 8?

using xcode version Version 8.0 (8A218a) on OSX El Capitan Versions 10.11.6. i'm trying to install a ruby gem that is reerencing the library /usr/lib/system/libsystem_symptoms.dylib (which indications point to it being an libxml2 ibrary). that library file does not exist. when i search, i find a .tdb file here:

/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib/system/libsystem_symptoms.tbd


which an answer in a separate question indicates that we should just link against the .dylib and not the .tdb. i'm fine with doing that, but i can't find the libsystem_symptoms.dylib.


thanks for your time!


-bk