Deploy and debug Modal endpoints for a Hugging Face TUI Space
Session from build-small-agent-trace on Hugging Face by drdavidtang · MIT · condensed by Coders Talk
Figure out how to test and deploy Modal-hosted MiniCPM and Nemotron inference endpoints for a Storyboard TUI app, then troubleshoot deployment and runtime failures until production worked.
- +0Prompt · +0Can you look at the modal deployment files and tell me how I should test the modal, since I don't think I've deployed them yet
- +0mAgent did · +0mInspected modal deploy scripts, backend provider, and app files; concluded nothing was deployed yet and explained the expected flow (modal setup, deploy, smoke test).
- +3mAgent did · +3mWalked through env var and secrets setup: BFL_IMAGE_MODEL, .gitignore, STORY_FORGE_API_KEY vs MODAL_API_KEY naming, /chat suffix requirements, GPU snapshot config, and scaledown windows.
- Break · 3h 52m away, not counted
- +31mFail · +31mModal image build failed: transformers==5.6.0 required huggingface_hub>=1.5.0 but repo pinned huggingface_hub==0.36.0.
- +32mAgent did · +32mBumped huggingface_hub to 1.5.0 in both minicpm.py and nemotron.py to satisfy the dependency resolver.
- Break · 1h 02m away, not counted
- +35mIntervention · +35mCancelled the agent's attempt to read .env before secrets were saved, then said to retry after saving them.Why: I hadn't actually saved the endpoint URLs yet, so I stopped it before it tried to read a stale or missing .env.
- +37mFail · +37mNemotron /chat calls hung or returned modal-http 404 'invalid function call', meaning the deployed URL no longer mapped to an active function.
- +49mAgent did · +49mDiagnosed Nemotron's truncated reply as reasoning-mode output, added enable_thinking=False to the chat template, redeployed, and confirmed a clean 'nemotron ready' response.
- +1h 6mFail · +1h 6mProduction error: JSONDecodeError 'Extra data' when parsing Nemotron's storyboard response because the greedy regex captured extra trailing text.
- +1h 6mAgent did · +1h 6mReplaced the greedy regex JSON extractor with json.JSONDecoder.raw_decode in backend/storyboard.py, added regression tests, and validated them manually since pytest wasn't installed.
- +1h 12mIntervention · +1h 12mInterrupted a failed git commit attempt (index.lock permission error) and told the agent to just push everything.Why: The first commit attempt silently failed on a filesystem permission error, so I told it to stage and push all the fixes regardless.
- +1h 39mOutcome · +1h 39mPushed two commits (c6b3143, 10bb2c8) to the Hugging Face Space main branch after resolving a rebase conflict over LFS-tracked binary assets; both Modal endpoints and the JSON parser fix went live.
Next time I'd start the session by asking the agent to check both Modal deployments end-to-end (health + authenticated /chat) before I go poking at env var naming one variable at a time, since most of the friction was just me and the agent working through STORY_FORGE_API_KEY vs MODAL_API_KEY confusion. The dependency pin fix and the enable_thinking=False change were the two things that actually unblocked real inference. The push at the end got messy because of an old local commit with raw image binaries clashing with the Space's LFS pointers, and cleanly separating that out from my actual fixes is what got it through.