cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration zombie-setpgid-leader.c -o zombie-setpgid-leader -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lintl -liconv
relibc getrlimit(3, 0x7ffffffffc80): not implemented
relibc getrlimit(3, 0x7ffffffffba0): not implemented
relibc getrlimit(9, 0x7ffffffffb60): not implemented
relibc getrlimit(9, 0x7ffffffffb90): not implemented
relibc getrlimit(5, 0x7ffffffffb90): not implemented
relibc getrlimit(9, 0x7ffffffffb60): not implemented
zombie-setpgid-leader.c: In function ‘main’:
zombie-setpgid-leader.c:19:14: error: implicit declaration of function ‘waitid’; did you mean ‘waitpid’? [-Werror=implicit-function-declaration]
   19 |         if ( waitid(P_PID, child, &info, WNOWAIT | WEXITED) < 0 )
      |              ^~~~~~
      |              waitpid
zombie-setpgid-leader.c:19:21: error: ‘P_PID’ undeclared (first use in this function)
   19 |         if ( waitid(P_PID, child, &info, WNOWAIT | WEXITED) < 0 )
      |                     ^~~~~
zombie-setpgid-leader.c:19:21: note: each undeclared identifier is reported only once for each function it appears in
cc1: some warnings being treated as errors