Always prefer explicit configuration settings over relying on implicit defaults or environmental behaviors in CI workflows and build configurations. This is particularly important for: 1. **Python version specifications**: Always explicitly specify the Python version in commands even when tools might detect it automatically. ```yaml # Good - explicitly specifies Python version - name: Set up Python 3.12 run: uv python install 3.12 - name: Install dependencies run: uv sync --python 3.12 --group docs ``` 2. **Dependency extras and groups**: Clearly state which extras and dependency groups are being included in installation commands. ```yaml # Good - explicitly states which extras are being installed - name: Install dependencies run: uv sync --extra timezone # Good - step name clearly indicates what's being tested - name: Test without email-validator run: ... ``` This approach prevents unexpected behaviors from implicit configurations (like .python-version files) and makes workflows more maintainable and predictable, especially in CI environments where consistency is critical.