Ah, so /tmp isn't going to work but /tmp/rancher-desktop/ would - you have to have it in one of the directories Rancher Desktop mounts by default or override some of the lima defaults
From the FAQ:
Q: Does file sharing work similarly to Docker Desktop? Do I have to do any additional configuration to mount volumes to VMs?
A: Currently, the following directories are shared by default: /Users/$USER on macOS, /home/$USER on Linux, and /tmp/rancher-desktop on both. For Windows, all files are automatically shared via WSL2.
