# ERROR: Could not build wheels for mypackage, which is required to install pyproject.toml-based projects

  error: invalid command 'bdist_wheel'

  ERROR: Failed building wheel for mypackage

- **ID:** `python/setuptools-build-backend-missing`
- **Domain:** python
- **Category:** install_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

The project's build-system.requires in pyproject.toml does not include 'wheel', and the legacy build backend (setuptools.build_meta:__legacy__) cannot build a wheel without it.

## Version Compatibility

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

## Workarounds

1. **** (98% success)
   ```
   [build-system]\nrequires = ["setuptools>=61", "wheel"]\nbuild-backend = "setuptools.build_meta"
   ```
2. **** (90% success)
   ```
   pip install --upgrade setuptools wheel && pip install mypackage
   ```

## Dead Ends

- **** — Forces source build, which still needs wheel to produce the artifact for installation. (85% fail)
- **** — Uses the ambient environment's setuptools, which may also lack wheel. (60% fail)