# FileNotFoundError: [Errno 2] No such file or directory: 'mypkg/data/config.yaml' during sdist install

- **ID:** `python/setuptools-manifest-in-missing-sdist-files`
- **Domain:** python
- **Category:** data_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

MANIFEST.in did not include the data file in the sdist, so the installed package is missing it. The error surfaces at runtime when the code tries to open the file.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.8 | active | — | — |
| 3.9 | active | — | — |
| 3.10 | active | — | — |
| 3.11 | active | — | — |
| 3.12 | active | — | — |

## Workarounds

1. **** (95% success)
   ```
   echo 'recursive-include mypkg/data *.yaml' >> MANIFEST.in
   ```
2. **** (97% success)
   ```
   [tool.setuptools.package-data]\nmypkg = ["data/*.yaml"]
   ```
3. **** (90% success)
   ```
   python -m build --sdist && tar -tzf dist/*.tar.gz | grep config.yaml
   ```

## Dead Ends

- **** — Reinstalling the same incomplete sdist produces the same result. (90% fail)
- **** — Not reproducible; breaks on the next install. (60% fail)