Our CI servers are already virtual machines. Or did you mean my local machine? We have a standard ecosystem that everyone uses, but there must be some difference between the CI server and our ecosystem. I simply haven't had the time to figure out what or why yet and it's better/easier to simply remove PowerMock where the tests are broken.
> 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.