cc -pipe -O   -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations signal/sig2str.c -o signal/sig2str -D_POSIX_C_SOURCE=202405L  -lm -lpthread -lrt  -lrt -lcrypt
signal/sig2str.c:5:27: error: 'sig2str' undeclared here (not in a function)
 int (*foo)(int, char *) = sig2str;
                           ^~~~~~~