Unable to use pre-compiled binaries

[dakmcinnis]

Environment:
Device: MacBook Pro (Mid 2015)
OS: macOS Big Sur Version 11.5.2
Processor: 2.2 GHz Quad-Core Intel Core i7
Memory: 16 GB 1600 MHz DDR3
Graphics: Intel Iris PRo 1536 MB

Expected Behaviour:
I should be able to use pre-compiled binaries (rather than A2 code), by using the following CMAKE command:

mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Debug -DHW2LIB_DIR=../lib/debug/mac/ ..
make

Current Behaviour:
When I run these commands, I get the following warning:

ld: warning: direct access in function 'write_ppm(std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator > const&, std::__1::vector<unsigned char, std::__1::allocator > const&, int, int, int)' from file '../lib/debug/mac/libhw2.a(write_ppm.cpp.o)' to global weak symbol 'std::__1::basic_ostream<char, std::__1::char_traits >& std::__1::endl<char, std::__1::char_traits >(std::__1::basic_ostream<char, std::__1::char_traits >&)' from file 'CMakeFiles/raytracing.dir/main.cpp.o' means the weak symbol cannot be overridden at runtime. This was likely caused by different translation units being compiled with different visibility settings.

Notes: Upon searching the issue myself, it seems to have to do with an fvisibility flag (but I'm not sure how to approach it).