How to generate Alignment error in C - Padding

#pragma pack (1)
struct s {
   char c;            // offset 0
   int i;             // offset 1!
} ss;
#pragma pack ()
 
void f_improper(int *p)
{
   *p = 23;        // generates a fault
}
 
void g_proper(int __unaligned *p)   // OK
{
   *p = 42;
}
 
void main ()
{
   f_improper(&ss.i);
   g_proper(&ss.i);
}