class A {
        this(int i) { _i = i; }

        invariant { assert(_i != 0); }
        int _i;
    }

    class B : A {
        this(int i, int j) {
            super(i);
            _j = j;
        }

        invariant { assert(_j != 0); } // line 15
        int _j;
    }

    int main() {
        B b = new B(8, 2);
        return 0;
    }

Compiles fine.  When run, the output is

    Error: AssertError Failure test.d(15)

 -- andy