cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations fcntl/struct-f_owner_ex.c -o fcntl/struct-f_owner_ex -D_POSIX_C_SOURCE=202405L -lm -lpthread -lnetwork -lbsd -latomic
fcntl/struct-f_owner_ex.c:2:19: error: storage size of 'foo' isn't known
    2 | struct f_owner_ex foo;
      |                   ^~~