Dev Random

... and sorry for the notification spam, resulting from a bunch of rebases.

Found another similar one - this time CircuitIO against ConnectionImpl. ``` com.google.common.util.concurrent.CycleDetectingLockFactory$PotentialDeadlockException: stream -> circuits, circuits -> stream at com.google.common.util.concurrent.CycleDetectingLockFactory$CycleDetectingReentrantLock.lock(CycleDetectingLockFactory.java:817) at com.subgraph.orchid.connections.ConnectionImpl.removeCircuit(ConnectionImpl.java:342) at com.subgraph.orchid.circuits.CircuitIO.destroyCircuit(CircuitIO.java:300) at com.subgraph.orchid.circuits.CircuitImpl.destroyCircuit(CircuitImpl.java:232) at com.subgraph.orchid.circuits.CircuitManagerImpl.stopBuildingCircuits(CircuitManagerImpl.java:101) at com.subgraph.orchid.TorClient.stop(TorClient.java:98)...

This is happening to us also, causing nodes to fall several minutes behind the rest of the network.

``` def _is_numeric(self, value): try: int(value) except (TypeError, ValueError): return False return True ``` This is bad from several points of view. It means that emails with leading digits will...

`isinstance(value, int)` would be the right thing to do here

alternatively, if you want to support strings, then match against `/^\d+$/`

it's expecting apt-cacher-ng to be listening on localhost. if you run `make-base-vm` without arguments, there's help on this topic.

> do you mean, run `bin/make-base-vm` instead of `bin/make-base-vm --lxc --arch amd64 --suite bionic`? Yes. You will see the help message.

duplicates #191

Likely needs a change to `Vagrantfile`.