DRONE_RUNNER_NETWORKS with an unavailable network

I think I stumbled across a bug. With this config:

DRONE_RUNNER_NETWORKS=net_a,net_b
DRONE_DEBUG=true
DRONE_TRACE=true

and only net_a is available the pipeline fails without logging the actual error. It was only after careful study of the database that I discovered this entry in stages.stage_error:

  Error response from daemon: network net_b not found

What I would expect is to see this error propagated to either the runner or the server logs (or both would be even better).

All I got was this on the server:

DEBU[0181] manager: updating step status                 step.id=557 step.name=clone step.status=running
DEBU[0182] manager: updating step status                 step.id=557 step.name=clone step.status=error

and this on the runner:

[timestamp] level=debug msg="updated stage to running" build.id=158 build.number=88 repo.id=11  [repo details snipped]
[timestamp] level=debug msg="destroying the pipeline environment" build.id=158 build.number=88 repo.id=11 [ repo details snipped]

The result of a missing network is catastrophic - the pipeline fails immediately without any indication of the actual error.

the error is normally visible in the user interface, however, there was a regression in the UI code that is preventing this from surfacing. This regression is known by the Drone team and they plan to have it resolved in the next release.