Mac/Unix: Use CXX to link dwtestoo instead of CC. This allowed me to compile dwtestoo with a different C++ compiler than the main library. Getting a crash when compiling the library with GCC 6, but it works with GCC from Xcode. GCC 6 compiles dwtestoo successfully and can use the Xcode GCC compiled library. CC=/usr/bin/gcc CXX=/usr/local/bin/gcc-6