Cleanup failing

[kalantar]

I am finding that after a build/push the cleanup step seems to have failed. The relevant log entries from /var/log/upstart/docker.log (IP addresses replaced) are:

2014/08/12 16:31:48 DELETE /v1.10/images/$MY_REGISTRY_HOST:5000/research/pyreka9
[28200d66] +job image_delete($MY_REGISTRY_HOST:5000/research/pyreka9)
Conflict, cannot delete b8502a3335bd because the container 2753d1f1c3cc is using it, use -f to force
[28200d66] -job image_delete($MY_REGISTRY_HOST:5000/research/pyreka9) = ERR (1)
[error] server.go:1048 Error making handler: Conflict, cannot delete b8502a3335bd because the container 2753d1f1c3cc is using it, use -f to force
[error] server.go:90 HTTP Error: statusCode=409 Conflict, cannot delete b8502a3335bd because the container 2753d1f1c3cc is using it, use -f to force

On the Docker host, There is, indeed a container 2753d1f1c3cc:

 CONTAINER ID        IMAGE                             COMMAND                CREATED             STATUS    
# docker ps -a | grep 2753d1f1c3cc
2753d1f1c3cc        b8502a3335bd                      /bin/sh -c '#(nop) C   21 minutes ago 

I don't really understand the COMMAND in the above entry; it seems to correspond to the CMD line of my Dockerfile.

While I can manually remove the container (actually, there are containers corresponding to each step of the Dockerfile -- all need to be removed) and them remove the image, I feel that this should be forced from the boatyard builder.