cc -O2 -pipe  -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations signal/psignal.c -o signal/psignal -D_POSIX_C_SOURCE=202405L  -lm -lpthread 
signal/psignal.c:5:8: error: incompatible function pointer types initializing 'void (*)(int, const char *)' with an expression of type 'void (unsigned int, const char *)' [-Werror,-Wincompatible-function-pointer-types]
void (*foo)(int, const char *) = psignal;
       ^                         ~~~~~~~
1 error generated.