cc -pipe -O   -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations math/M_1_PIl.c -o math/M_1_PIl -D_POSIX_C_SOURCE=202405L  -lm -lpthread -lrt  -lrt -lcrypt
math/M_1_PIl.c:8:26: error: 'M_1_PIl' undeclared here (not in a function); did you mean 'M_1_PI'?
 long double  const foo = M_1_PIl;
                          ^~~~~~~
                          M_1_PI