/opt/IBM/openxlC/17.1.1/bin/ibm-clang -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations unistd/_SC_V8_LP64_OFF64.c -o unistd/_SC_V8_LP64_OFF64 -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -latomic
unistd/_SC_V8_LP64_OFF64.c:2:17: error: use of undeclared identifier '_SC_V8_LP64_OFF64'
int const foo = _SC_V8_LP64_OFF64;
                ^
1 error generated.