For this declaration:

struct Point(X, Y) { ... }

unittest {
    alias Point = Point!(double, double);
    ...
}

the compiler issues:

Error: alias Point recursive alias declaration

The fix is to prepend a dot:

    alias Point = .Point!(double, double);

That's a rather obscure intervention. So I suggest that the error message makes that suggestion wherever sensible, i.e. in this case it would read:

Error: alias Point recursive alias declaration, did you mean `alias Point = .Point!(double, double)`?