broken config in the child stops parent initialization

gistfile1.txt

[2017-04-08 18:36:59.465][16][warning][main] initializing epoch 0 (hot restart version=7.2490552)
[2017-04-08 18:36:59.468][16][warning][main] starting main dispatch loop
[2017-04-08 18:36:59.469][16][warning][main] all clusters initialized. initializing init manager
[2017-04-08 18:36:59.469][16][warning][main] all dependencies initialized. starting workers

# Attempt 1 to start with a broken config

I0408 18:37:00.217785       1 watcher.go:164] Envoy command: [-c /etc/envoy/envoy-rev1.json --restart-epoch 1 --drain-time-s 2 --parent-shutdown-time-s 3 --service-cluster istio-proxy --service-node ingress]
[2017-04-08 18:37:00.222][21][warning][main] initializing epoch 1 (hot restart version=7.2490552)
[2017-04-08 18:37:00.223][16][warning][main] shutting down admin due to child startup
[2017-04-08 18:37:00.223][16][warning][main] terminating parent process
[2017-04-08 18:37:00.228][21][critical][main] error initializing configuration '/etc/envoy/envoy-rev1.json': Failed to load private key file /etc/tls.key
I0408 18:37:00.229311       1 agent.go:171] Epoch 1 terminated with an error: exit status 1

# Attempt 2..10 to start envoy fail with same reason - epoch 0 is still initializing

I0408 18:37:00.617422       1 agent.go:196] Reconciling after delay 100ms (budget 9)
I0408 18:37:00.618375       1 watcher.go:164] Envoy command: [-c /etc/envoy/envoy-rev1.json --restart-epoch 1 --drain-time-s 2 --parent-shutdown-time-s 3 --service-cluster istio-proxy --service-node ingress]
unable to initialize hot restart: previous envoy process is still initializing
I0408 18:37:00.623552       1 agent.go:171] Epoch 1 terminated with an error: exit status 1
[2017-04-08 18:37:02.467][16][warning][main] shutting down parent after drain