Cannot access inner member by reference when structs are generic

[mlbrooks]

Minimal example:

forall( dtype T )
struct a {};

struct b1 {
    a(int) aa;
};

forall( dtype T )
struct b2 {
    a(T) aa;
};

int main() {
    #ifndef THE_ERROR
    b1 thingb;
    #else
    b2(int) thingb;
    #endif

    a(int) & thinga = thingb.aa;
}

On the error, message is:

CFA Version 1.0.0 (debug)
thebug.cfa: In function ‘_X4mainFi___1’:
thebug.cfa:21:36: error: lvalue required as unary ‘&’ operand
     a(int) & thinga = thingb.aa;