zaproxy: Baseline XSERVTransmkdir: ERROR using Docker

Describe the bug

When running zap2docker (live, stable, weekly), it will say ERROR for XSERVTransmkdir with the output below. This has been reproduced on 2 different servers.

root@dockerhost:~# docker run -t owasp/zap2docker-weekly zap-baseline.py -t https://www.example.com
2019-02-20 18:54:21,798 Params: ['zap-x.sh', '-daemon', '-port', '36156', '-host', '0.0.0.0', '-config', 'api.disablekey=true', '-config', 'api.addrs.addr.name=.*', '-config', 'api.addrs.addr.regex=true', '-config', 'spider.maxDuration=1', '-addonupdate', '-addoninstall', 'pscanrulesBeta']
_XSERVTransmkdir: ERROR: euid != 0,directory /tmp/.X11-unix will not be created.
Feb 20, 2019 6:54:30 PM java.util.prefs.FileSystemPreferences$1 run

To Reproduce Steps to reproduce the behavior:

1. Run the following command:

docker run -t owasp/zap2docker-weekly zap-baseline.py -t https://www.example.com

Expected behavior Start running the baseline scan from the Docker container

Software versions

• ZAP: [live, stable, weekly]
• OS: [zap2docker, ubuntu host]
• Java: [Container version - java-8-openjdk-amd64]

Errors from the zap.log file It seems the error only shows up in the CLI, but no mention in the zap.out. I might be wrong on this one.

Additional context

Integration in a CICD pipeline

Thanks!