Streamlit fails to install librairy while deploying app

Deployment
1

while deploying the app, streamlit fails to install schwabdev, although its referenced on PyPI: Client Challenge here is the code output:

ModuleNotFoundError: No module named 'schwabdev'

2026-02-13 22:26:56.444 503 GET /script-health-check (127.0.0.1) 253.30ms

Attempting uninstall: mdurl

Found existing installation: mdurl 0.1.2

Uninstalling mdurl-0.1.2:

Successfully uninstalled mdurl-0.1.2

Attempting uninstall: markdown-it-py

Found existing installation: markdown-it-py 4.0.0

Uninstalling markdown-it-py-4.0.0:

Successfully uninstalled markdown-it-py-4.0.0

Attempting uninstall: rich

Found existing installation: rich 14.3.2

Uninstalling rich-14.3.2:

Successfully uninstalled rich-14.3.2

Successfully installed markdown-it-py-4.0.0 mdurl-0.1.2 pygments-2.19.2 rich-14.3.2

[notice] A new release of pip is available: 24.0 -> 26.0.1

[notice] To update, run: pip install --upgrade pip

────────────────────────────────────────────────────────────────────────────────────────

[22:26:58] ❗️ installer returned a non-zero exit code

2

Hey there, thanks for sharing your deployment issue! If Streamlit Cloud can’t install schwabdev even though it’s on PyPI, the most common causes are Python version incompatibility or a typo/misconfiguration in requirements.txt. According to PyPI, schwabdev requires Python >=3.11. If your app is set to use an older or unsupported Python version, installation will fail. Also, make sure your requirements.txt lists schwabdev (not pip install schwabdev or any other command) on its own line.

If you’re already using Python 3.11+ and the requirements.txt is correct, double-check the deployment logs for any additional errors about version conflicts or unsupported wheels. Some packages may not yet have wheels for the very latest Python versions (like 3.13), so try setting your app to use Python 3.11 or 3.12 in the deployment settings. For more, see the official schwabdev PyPI page and Streamlit’s dependency docs.

Sources: