cc -O2 -pipe -pthread -I/usr/local/include  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations math/M_PHIl.c -o math/M_PHIl -D_POSIX_C_SOURCE=202405L  -lm -lpthread -lrt -L/usr/local/lib  -lintl -lstdthreads -lcrypt
math/M_PHIl.c:8:26: error: use of undeclared identifier 'M_PHIl'
    8 | long double  const foo = M_PHIl;
      |                          ^
1 error generated.