# pkg_resources.extern.packaging.requirements.InvalidRequirement: Invalid environment marker: python_version >= '3.7' and

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

## Root Cause

A package's metadata contains a malformed environment marker, typically due to a missing operand after 'and' or 'or'. This can happen with hand-edited setup.py or a bug in packaging tools.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.7 | active | — | — |
| 3.8 | active | — | — |
| 3.9 | active | — | — |
| 3.10 | active | — | — |

## Workarounds

1. **** (70% success)
   ```
   Contact the package maintainer to fix the metadata. As a temporary workaround, install with --no-deps and manually install dependencies.
   ```
2. **** (90% success)
   ```
   If you control the package, correct the environment marker in setup.py (e.g., ensure it ends with a valid expression) and rebuild.
   ```

## Dead Ends

- **** — The malformed marker prevents proper dependency resolution; force install may skip dependencies. (80% fail)
- **** — The issue is in the package's metadata, not the packaging library. (85% fail)