Comment 3 for bug 1592210

This panic is present in the machine log:

panic: send on closed channel

goroutine 321 [running]:
panic(0x1cecb00, 0xc8201178b0)
 /usr/lib/go-1.6/src/runtime/panic.go:464 +0x3e6
github.com/godbus/dbus.(*Conn).inWorker(0xc8203b5320)
 /build/juju-core-2avUTs/juju-core-2.0-beta9~20160608~4037~719e6ec/src/github.com/godbus/dbus/conn.go:327 +0x1048
created by github.com/godbus/dbus.(*Conn).Auth
 /build/juju-core-2avUTs/juju-core-2.0-beta9~20160608~4037~719e6ec/src/github.com/godbus/dbus/auth.go:118 +0xf3d