# packaging.version.InvalidVersion: Invalid version: '1.0.0-rc1+build.123'

- **ID:** `python/packaging-invalid-version-string`
- **Domain:** python
- **Category:** data_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

The version string does not conform to PEP 440; local version labels must start with a digit after the '+'.

## Version Compatibility

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

## Workarounds

1. **** (95% success)
   ```
   version = '1.0.0rc1+build123'  # local label 'build123' starts with digit
   ```
2. **** (0% success)
   ```
   from packaging.version import Version; v = Version('1.0.0rc1+build123')  # will raise error; fix the string first
   ```

## Dead Ends

- **** — Removing build metadata may lose important build information; parsing may still fail if other parts are invalid. (50% fail)
- **** — The version is still invalid per PEP 440; older libraries may not raise error but will parse incorrectly. (80% fail)