James Munns: i get the following warning when my test stops while it's executing the drop handlers (i see log output from one of my drop handlers before):
```
WARN  postcard_rpc::host_client::util] Receiver Closed, this could be bad
```

i guess it's safe to ignore it, but it's also _not great_ to have this warning in the log.
do you know what the usual reasons are which could be causing this? i.e. what i could look at to find the source? maybe something in the drop order is wrong?