Tobi McNamobi focused on improving test environment stability for the pytest-dev/pytest repository by addressing unreliable test runs caused by the PYTEST_PLUGINS environment variable. Using Python and leveraging skills in CI/CD and environment configuration, Tobi identified that setting this variable led to inconsistent test discovery and execution, which disrupted continuous integration reliability. By implementing a targeted patch that unsets PYTEST_PLUGINS during test runs, Tobi ensured more predictable and maintainable CI outcomes. The work included clear documentation on environment-variable handling, supporting future contributors and reducing onboarding friction. This contribution demonstrated careful analysis and a practical approach to enhancing automated testing workflows.