CMake Warning:
  Manually-specified variables were not used by the project:

    ALSOFT_TESTS
    CMAKE_EXPORT_NO_PACKAGE_REGISTRY


/Applications/Xcode-11.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ranlib: file: ../lib/libcommon.a(alfstream.cpp.o) has no symbols
/Applications/Xcode-11.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ranlib: file: ../lib/libcommon.a(alfstream.cpp.o) has no symbols
CMake Warning:
  Manually-specified variables were not used by the project:

    CMAKE_EXPORT_NO_PACKAGE_REGISTRY


openal/1.21.0: WARN: openal requires a compiler supporting c++14. I don't know whether your compiler does, so I assume it does.