I don't know if this has been reported yet.

If you compile a.d, this gives a forward reference error citing "e" and then seg. faults.

<code file="a.d">
import b;
template t ( e f ) { }
</code>

<code file="b.d">
import a;
enum e { v }
</code>

p.s. this was from memory so it might no be right