gcc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations fcntl/struct-f_owner_ex-pid.c -o fcntl/struct-f_owner_ex-pid -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -lxnet -lsocket -latomic
fcntl/struct-f_owner_ex-pid.c:2:17: error: 'struct f_owner_ex' declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
    2 | void foo(struct f_owner_ex* bar)
      |                 ^~~~~~~~~~
fcntl/struct-f_owner_ex-pid.c: In function 'foo':
fcntl/struct-f_owner_ex-pid.c:4:26: error: invalid use of undefined type 'struct f_owner_ex'
    4 |         pid_t *qux = &bar->pid;
      |                          ^~
cc1: all warnings being treated as errors