I was compiling code from someone using a Makefile. It gave this error:
/usr/bin/ld: main.o: undefined reference to symbol '_ZN5boost6system15system_categoryEv'
If you demangle the C++ symbol
_ZN5boost6system15system_categoryEv using C++Filt you get the function
boost::system::system_category(). So, the code was using this function, but was missing the library file. Adding the linker directive
-lboost_system to include the library, fixed the error.
Tried with: Ubuntu 14.04