# ERROR: Cannot install package-a==1.0 and package-b==2.0 because these package versions have conflicting dependencies.
The conflict is caused by:
    The user requested package-a==1.0
    package-b 2.0 depends on package-a<1.0

- **ID:** `python/pip-resolution-too-deep-backtracking`
- **Domain:** python
- **Category:** install_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

The dependency graph is unsatisfiable: two pinned requirements transitively require incompatible versions of a shared package.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.x | active | — | — |

## Workarounds

1. **** (90% success)
   ```
   pip install 'package-a>=0.9,<1.0' 'package-b==2.0'
   ```
2. **** (85% success)
   ```
   pip install --dry-run --report report.json package-a==1.0 package-b==2.0
python -m json.tool report.json | less
   ```

## Dead Ends

- **** — Force install does not resolve version conflicts; pip still refuses to pick a solution. (85% fail)
- **** — The legacy resolver may install an inconsistent set, leading to runtime ImportErrors later. (70% fail)
- **** — Unpinned installs may still conflict on transitive constraints and reproduce the error. (60% fail)