The start_docker.py script was checking /var/run/docker.sock first,
which inside CI containers is an inner dockerd (v29.5.3) with data
root on the container's 38G overlay (often 100% full). When
_get_docker_free_bytes() returned 0 (data root path not accessible
from inside container), the script assumed it was the host Docker
with plenty of space and returned True immediately — without trying
the host's rootless Docker socket at /run/host-docker.sock.
Fix: try /run/host-docker.sock FIRST (before /var/run/docker.sock).
The host socket is mounted by the gitea runner config and has access
to the host's full filesystem (455G). Only trust free_bytes == 0
(= data root not accessible from container) for /run/host-docker.sock,
since the host's root dir is genuinely outside the container. For
other sockets (inner dockerd), free_bytes == 0 means the path doesn't
exist inside the container — don't trust it.
Generated with [Devin](https://devin.ai)
Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
