The following code fragment causes the compiler to crash with the following useful information:

"dmd.exe has encountered a problem and needs to close.  We are sorry for the inconvenience."

//--------------------
public S s = S();

public struct S {
    private int[] a = [ 0 ];
}
//--------------------

I realize the code is incorrect, but I expected an error message, not a trainwreck.

Adding initializer information solves the problem:

//--------------------
public S s = S([0]); // compiles correctly

public struct S {
    private int[] a = [ 0 ];
}
//--------------------

Eliminating the forward reference solves the problem:

//--------------------
public struct S {
    private int[] a = [ 0 ];
}

public S s = S(); // compiles correctly
//--------------------