../../hostmux/hostmux.c:97:67: error: expected ';' at end of declaration
  error_t parse_opt (int key, char *arg, struct argp_state *state)
                                                                  ^
                                                                  ;
../../hostmux/hostmux.c:119:16: error: use of undeclared identifier 'argp'
  argp_parse (&argp, argc, argv, ARGP_IN_ORDER, 0, 0);
               ^
2 errors generated.