gcc -pthread  -Wall -Wextra -Werror=implicit-function-declaration signal/sigwait.c -o signal/sigwait -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lxnet -lsocket -latomic
signal/sigwait.c: In function 'main':
signal/sigwait.c:16:23: error: too many arguments to function 'sigwait'
   16 |         if ( (errno = sigwait(&set, &signo)) < 0 )
      |                       ^~~~~~~
In file included from signal/sigwait.c:3:
/usr/include/signal.h:165:12: note: declared here
  165 | extern int sigwait(sigset_t *);
      |            ^~~~~~~