> there must be some difference between the CI server and our ecosystem Well that's why I suggested using Docker: To ensure both environments are exactly the s

> there must be some difference between the CI server and our ecosystem Well that's why I suggested using Docker: To ensure both environments are exactly the same. You say they are virtual machines, but how do you provision them? I assume you are using puppet/chef/salt/ansible and creating them from scratch, as opposed to uploading whatever image you used in dev, like you would with Docker.