When compiling on Linux, using the clang 7.0.1 compiler, std=c+14, stdlib=libc+, the build aborts on an ambiguous overload in change_stream.cpp, line 111:

out.append(bsoncxx::builder::basic::kvp("maxAwaitTimeMS", count));

Casting the second parameter allows the compile to proceed:

out.append(bsoncxx::builder::basic::kvp("maxAwaitTimeMS", static_cast<int64_t>(count)));