# ERROR: Could not find a version that satisfies the requirement hatchling (from versions: none)
ERROR: No matching distribution found for hatchling

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

## Root Cause

The package's pyproject.toml declares a build backend (e.g., hatchling) that is not available on the configured index, often because a private mirror lacks it.

## Version Compatibility

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

## Workarounds

1. **** (90% success)
   ```
   Add PyPI as a secondary index: `pip install --extra-index-url https://pypi.org/simple <pkg>`.
   ```
2. **** (88% success)
   ```
   Pre-install the build backend and disable isolation: `pip install hatchling && pip install --no-build-isolation <pkg>`.
   ```

## Dead Ends

- **** — Uses the current env's build backend; if hatchling is not installed there either, the same error appears. (70% fail)
- **** — pip cannot conjure a package the index does not serve. (90% fail)