It's not a big deal, but...

void main()
{
    int[int] k;
    k.length = 3;
}

I think the error message is a little cryptic:
bad_err_msg.d(4): '_aaLen(k)' is not an lvalue


How about... ?
good_err_msg.d(4): Can't assign to associative array length

-- 
Justin (a/k/a jcc7)
http://jcc_7.tripod.com/d/