Denis Mazur enabled flexible PyTorch version selection for local builds in the pytorch/tensordict repository by activating environment-variable-based configuration within setup.py. By uncommenting and refining the local-build logic, Denis allowed developers to specify the desired PyTorch version through the PYTORCH_VERSION environment variable, streamlining the build process and reducing version-related troubleshooting. This approach improved build reproducibility and simplified onboarding for new contributors. The work demonstrated practical use of Python scripting, build system configuration, and environment variable management. While the contribution was focused and did not involve bug fixes, it addressed a common pain point in local development workflows with targeted engineering.