Carthage console tab-completion breaks when AsyncRequired raises from attributes

[srak289]

For instance tab-completing
layout.Range.internet.machine.<TAB> -> does nothing

The following snippet shows determining which attribute is causing the error.

>>> errors = []
>>> for x in dir(layout.Range.internet.machine):
...     try:
...             a=getattr(layout.Range.internet.machine, x)
...     except Exception as e:
...             errors.append((str(e), x))
... 
>>> errors
[('Asynchronous dependency injected into non-asynchronous context Instantiating InjectionKey(SshKey) using <Injector base injector> for <Injector claimed by <Vm name:internet.range ip_address:192.168.63.224>>', 'ssh')]