Lib dependency Opus:

one of the dependencies, Opus, doesn't immediately compile on Raspberry. It needs the -DOPUS_DISABLE_INTRINSICS=ON option when generating the CMake files in libDiscordBot/build
You can read the entire struggle of finding the solution here : xiph/opus#203

Compiling the bot with the lib:

On Raspberry Pis, the default Atomic standard library doesn't include the call __atomic_fetch_add_8. To compile the bot, the linker option -latomic had to be added. I modified the CMakeLists.txt file as indicated below, following this StackOverflow answer, but I'm not sure at all if it's a good way to do it.

set(GCC_COVERAGE_LINK_FLAGS "-latomic")
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${GCC_COVERAGE_LINK_FLAGS}")

This is not a big deal, but I think it could be of interest to you.