Note: This is not an issue but a question; I'd start a "discussion" but those don't seem to be enabled for this GitHub project.
I use and enjoy https://github.com/cirruslabs/tart + https://github.com/cirruslabs/gitlab-tart-executor today for macOS build jobs and have been following the development of vetu with interest as a potential replacement to VirtualBox for virtualized Linux build jobs in GitLab. I now wonder: Do you have any plans on implementing a gitlab-vetu-executor similar to gitlab-tart-executor?