/opt/IBM/openxlC/17.1.1/bin/ibm-clang -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations spawn/POSIX_SPAWN_SETSID.c -o spawn/POSIX_SPAWN_SETSID -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -latomic
spawn/POSIX_SPAWN_SETSID.c:3:17: error: use of undeclared identifier 'POSIX_SPAWN_SETSID'
int const foo = POSIX_SPAWN_SETSID;
                ^
1 error generated.