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