Cello docker restart

After a "make redeploy service=dashboard"
I read:
Redeploy the cello-dashboard container
Creating dashbard

I can only call this (not cello-dashboard, neither cello-dashbard):
docker exec -it dashbard bash

But I can not log in, it drops out me with this message:
Error response from daemon: Container 761277d839a6b625081f497f04ea37636fb17c54ce1ba84406a09ba19242451c is restarting, wait until the container is running

docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                              PORTS    NAMES
761277d839a6        cello-dashbard      "python dashboard.py"    11 minutes ago      Restarting (1) 2 minutes ago                 dashbard
...

In the "make log" I read:

dashbard      | Traceback (most recent call last):
dashbard      |   File "dashboard.py", line 4, in <module>
dashbard      |     from resources import bp_index, \
dashbard      |   File "/app/resources/__init__.py", line 1, in <module>
dashbard      |     from .index import bp_index
dashbard      |   File "/app/resources/index.py", line 17, in <module>
dashbard      |     from modules import cluster_handler, host_handler
dashbard      |   File "/app/modules/__init__.py", line 1, in <module>
dashbard      |     from .cluster import cluster_handler
dashbard      |   File "/app/modules/cluster.py", line 14, in <module>
dashbard      |     from agent import get_swarm_node_ip, \
dashbard      |   File "/app/agent/__init__.py", line 1, in <module>
dashbard      |     from .docker_swarm import get_project, \
dashbard      |   File "/app/agent/docker_swarm.py", line 10, in <module>
dashbard      |     from docker import Client
dashbard      | ImportError: cannot import name 'Client'


I suppose dashboard continuosly restarts itself...