Actually, I just now realized that I didn't have this compile error with "argus" but, instead with "argus-clients" that I submitted at the same time.

I am new to this so, please help me through it...

Could compiling the server and client programs differently introduce unexpected problems? Seems plausible to me.

If we want to solve the issue from the other direction, the full error that I am getting when compiling "argus-clients" is:

Undefined symbols for architecture x86_64:
  "_xdtoi", referenced from:
      _argus_ether_aton in argus_common.a(argus_util.o)
ld: symbol(s) not found for architecture x86_64
make[1]: *** [../bin/ra] Error 1
make[1]: *** Waiting for unfinished jobs....
clang: error: linker command failed with exit code 1 (use -v to see invocation)