void fun()
{
    int x = 2;
    struct A
    {   
        int a;
        this(int a)
        {   
            this.a = a + x;      // segault here
        }
    }

    A a = 5;
    // A a = A(5); initializing `a` like this works as expected                                                                                                                              
}

void main()
{
    fun();
}