# ModuleNotFoundError: No module named 'setuptools'
  [end of output]
  note: This error originates from a subprocess, and is likely not a problem with pip.

- **ID:** `python/pip-build-isolation-no-module-named-setuptools`
- **Domain:** python
- **Category:** module_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

With build isolation, pip creates a temp env and installs build deps from pyproject.toml. If [build-system] is missing or requires only 'wheel', setuptools isn't present and the build fails.

## Version Compatibility

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

## Workarounds

1. **** (92% success)
   ```
   # pyproject.toml
[build-system]
requires = ["setuptools>=64", "wheel"]
build-backend = "setuptools.build_meta"
   ```
2. **** (85% success)
   ```
   pip install --upgrade setuptools wheel
pip install . --no-build-isolation
   ```

## Dead Ends

- **** — Build isolation ignores the outer env. (90% fail)
- **** — Doesn't populate the isolated build env. (80% fail)
- **** — Removes PEP 518 config; pip falls back to legacy but may still fail. (70% fail)