U2Net only ever downloaded lazily on the first Remove Background click,
unlike SAM which retries on every container start. If that one attempt
failed (DNS/firewall) the model was never fetched again, surfacing as
"No background removal method available. Install u2net or rembg."
Mirrors the existing SAM auto-download/AUTO_DOWNLOAD_SAM pattern for
U2Net, and documents manual host-side recovery in the README.
Also deletes backend/app/services/u2net_model.py (hand-written
U2NET/U2NETP PyTorch classes) — unused since tools.py switched to
cv2.dnn.readNetFromONNX for background removal.
Build / pip layer fixes:
- Add BUILDID ARG to Dockerfile.gpu; pass from docker-compose.gpu.yml build args
so pip layers can be force-busted without --no-cache:
BUILDID=$(date +%s) docker compose -f docker-compose.gpu.yml up --build
Model download (DNS-blocked environments):
- Change HF model cache from named volume to ./data/hf_cache bind mount
so models can be pre-downloaded on the host (no rebuild needed)
- Remove now-unused hf_model_cache named volume
- README: add iptables fix + huggingface-cli offline download instructions
Error handling improvements:
- ai_edit_region: catch ConnectError/Errno-3 → return 503 with exact fix commands
- _require_remote: give actionable message when local_gpu provider fails to load
- _build_provider: catch AttributeError (torch.xpu from wrong diffusers) not just ImportError
- local_diffusion.py: fix docstring to reflect <0.29.0 pin
https://claude.ai/code/session_01WVDg7amsy1TTtxvpku7bcM
1.1.1.1 uses a different anycast route than 8.8.8.8 so may reach the
container even when Google's servers don't. Falls back to Google if
Cloudflare is also unreachable. If all fail (Errno -3), port 53 UDP is
blocked at the Docker bridge level — comment has the iptables fix.
https://claude.ai/code/session_01WVDg7amsy1TTtxvpku7bcM