Docker service "worker" stuck at preparing in stack deploy from the swarm votingapp tutorial

I have followed the swarm voting lab from docker and after deploying docker stack deploy --compose-file docker-stack.yml vote every service except one starts, while one gets stuck with status preparing. docker service logs vote_worker is empty and I have tried deploying twice and creating the service manually and it always freezes before the container gets created. I can’t figure out why. Maybe there is a command which shows a verbose output of services after they are deployed so I can see what command it’s hanging on?

docker service ls
ID                  NAME                MODE                REPLICAS            IMAGE                                          PORTS
mnidupsayek0        vote_db             replicated          1/1                 postgres:9.4
vbuskn6gvfrd        vote_redis          replicated          1/1                 redis:alpine                                   *:30001->6379/tcp
xsr0i67zortf        vote_result         replicated          1/1                 dockersamples/examplevotingapp_result:after    *:5001->80/tcp
mpr7pbeub2yj        vote_visualizer     replicated          1/1                 dockersamples/visualizer:stable                *:8080->8080/tcp
9gqc6jgelil7        vote_vote           replicated          2/2                 dockersamples/examplevotingapp_vote:after      *:5000->80/tcp
ga0eoqcaioe0        vote_worker         replicated          0/1                 dockersamples/examplevotingapp_worker:latest