/opt/IBM/openxlC/17.1.1/bin/ibm-clang -pthread -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations fcntl/F_GETOWN_EX.c -o fcntl/F_GETOWN_EX -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -latomic fcntl/F_GETOWN_EX.c:3:2: error: "F_GETOWN_EX is not defined" #error "F_GETOWN_EX is not defined" ^ 1 error generated.