Streamlit Cloud app stuck on “Your app is in the oven” even after minimal app and correct file path

Community Cloud
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1

Hi everyone,

I’m trying to deploy a Streamlit app from GitHub on Streamlit Community Cloud, but the app is stuck on the “Your app is in the oven” screen indefinitely.

I’ve already tried the usual fixes:

  • Corrected the Main file path to app.py.

  • Kept app.py in the repo root.

  • Simplified the app to a minimal hello-world Streamlit app.

  • Reduced dependencies in requirements.txt.

  • Confirmed the repo is pushing correctly to GitHub.

  • Added debug output to check whether the app starts at all.

Repo structure

text

delhi-school-air-pollution-dashboard/
├── app.py
├── requirements.txt
├── runtime.txt
├── README.md
├── data/
│ └── processed/
│ ├── schools_with_exposure.csv
│ └── other processed CSV files
└── notebooks/

Minimal app.py I tested

python

importstreamlitas st

st.write("hello")

I also tested a slightly larger debug version with file checks, but the app still never gets past the loading screen.

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image1920×1049 196 KB

Public github repo: GitHub - hacback17/Delhi-school-air-pollution-dashboard: Delhi school air pollution dashboard · GitHub

2

Welcome to the Streamlit community, and thanks for sharing your detailed troubleshooting steps and repo! :rocket: You’re not alone—many users encounter the “Your app is in the oven” issue on Streamlit Community Cloud, especially when the logs show successful provisioning, cloning, and dependency processing, but the app never loads or logs any output from app.py. This is often caused by Python version incompatibility, problematic requirements.txt, or a platform-level issue.

Based on your logs and repo structure, here’s what you should check next:

  • Make sure your requirements.txt does NOT include built-in modules (like python or pickle), and only lists packages you actually use. Don’t specify the Python version in requirements.txt—set it in the Cloud “Advanced settings” instead.
  • Streamlit Community Cloud currently defaults to Python 3.14.x, but many data science packages (like pandas, numpy, etc.) may not yet support 3.14. Try setting your app’s Python version to 3.12 or 3.11 in the Cloud settings, then reboot the app.
  • If you have a runtime.txt, note that it’s currently ignored by Community Cloud, so only the dashboard setting matters for Python version selection.
  • If the app still hangs, try a minimal requirements.txt (just streamlit) and a minimal app.py (just st.write(“hello”)) to rule out dependency or code issues. If it still doesn’t load, it’s likely a platform issue—these sometimes resolve after a backend update or service restart.

For more details and step-by-step troubleshooting, see the official docs and similar forum threads: App dependencies, Resource limits, Python version issues, and Forum: stuck in the oven. If you’re still stuck, please share your requirements.txt and any Cloud logs—community members are always happy to help debug! :tada:

Sources:

3

This might be caused by a bug in pyarrow 25.0.0: [C++][Python] SIGSEGV in bundled mimalloc mi_thread_init when libarrow is first loaded on a non-main thread that exits (mimalloc 3.3.x, pyarrow 25.0.0) · Issue #50471 · apache/arrow · GitHub
Update to Streamlit 1.59.2 or pin pyarrow < 25.0.0 to prevent this crash