struct List(T)
{
    T[] S;

    void bug(void delegate(inout T) f)
    {
        f(S[0]);
    }
}

void main()
{
    List!(bit) a;
}

>dmd.exe test.d
internal error: ..\ztc\cgcs.c 353

XP DMD 0.98

The bug does not manifest if either
- the delegate parameter is not inout'd or
- the List argument is not bit

The full source compilation will halt with this error

internal error: ..\ztc\cod2.c 4184

If that helps...