clang -O2  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations math/M_2_SQRTPIl.c -o math/M_2_SQRTPIl -D_POSIX_C_SOURCE=202405L  -lm  -lintl
math/M_2_SQRTPIl.c:8:26: error: use of undeclared identifier 'M_2_SQRTPIl'
long double  const foo = M_2_SQRTPIl;
                         ^
1 error generated.