a.c:
#include <stdio.h>
#include <net/if.h>

int main()
{
    unsigned int z;
    z=-1;
    printf("Max: %u\n", z);
    return 0;
}



In file included from a.c:2:
/usr/include/net/if.h:213: error: field 'ifru_addr' has incomplete type
/usr/include/net/if.h:214: error: field 'ifru_dstaddr' has incomplete type
/usr/include/net/if.h:215: error: field 'ifru_broadaddr' has incomplete type
/usr/include/net/if.h:250: error: field 'ifra_addr' has incomplete type
/usr/include/net/if.h:251: error: field 'ifra_broadaddr' has incomplete type
/usr/include/net/if.h:252: error: field 'ifra_mask' has incomplete type
/usr/include/net/if.h:318: error: field 'addr' has incomplete type
/usr/include/net/if.h:319: error: field 'dstaddr' has incomplete type