# ValueError: python_requires must be a string containing a valid version specifier, not '>=3.6, <4.0'

- **ID:** `python/setuptools-python-requires-invalid`
- **Domain:** python
- **Category:** config_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

The python_requires value has a syntax error, such as an extra space or invalid operator.

## Version Compatibility

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

## Workarounds

1. **Correct the python_requires string to PEP 440 format** (95% success)
   ```
   python_requires = '>=3.6,<4.0' (no spaces around comma)
   ```
2. **Use a single specifier if possible** (90% success)
   ```
   python_requires = '>=3.6'
   ```

## Dead Ends

- **Using a list of specifiers** — setuptools expects a single string, not a list. (90% fail)
- **Removing the space after the comma** — The error is about the format; a single string with commas is acceptable. (80% fail)