Error4 reports
Fix ModuleNotFoundError
in uv
✅ Solution
This error usually means Python can't find the required module, often because the virtual environment isn't correctly activated or the package isn't installed within it. Ensure the virtual environment created by `uv` is properly activated before running your script (e.g., using `source .venv/bin/activate` on Unix-like systems) and that the necessary package is installed using `uv pip install <package_name>` within the activated environment. If using `uv run`, verify that it's configured to use the correct virtual environment, possibly by specifying the `--venv` flag if needed.
Related Issues
Real GitHub issues where developers encountered this error:
uv created virtual environment not working for uWSGI when using --uid --gidJan 5, 2026
ModuleNotFoundError when running with `uv run`, but works fine with activated virtual environmentDec 13, 2025
uv: local package randomly becomes unimportable in project created with `uv init --package`Dec 4, 2025
uv sync --no-managed-python doesn't make packages available to system Python interpreterDec 2, 2025
Timeline
First reported:Dec 2, 2025
Last reported:Jan 5, 2026