Troubleshoot containers and pods lacking shell and/or debugging tools. Forward unpublished or even localhost ports to your host system. Expose endpoints from the host system to containers & Kubernetes ...
So this is a weird one. Using v1.19.1 worked fine. I could run it from the CLI without issue using retroarch, or from Emulationstation. After upgrading to v1.21.0, running retroarch from the CLI ...