There still seems to be an issue here on sync_up when using DockerSyncer:
invalid output path: directory "/tmp/ray_tmp_mount/...
Interestingly earlier in the logs I see the directory being created:
VINFO command_runner.py:474 -- Running `^[[1mmkdir -p /tmp/ray_tmp_mount/...
I’ve made a comment to an issue with a similar offending directory: https://github.com/ray-project/ray/issues/12104.