During March 2025, Charles Pepin focused on stabilizing local testing workflows in the facebook/buck2-prelude repository. He addressed a persistent bug by making SimInfo attributes nullable, allowing the system to gracefully handle device references that no longer exist on disk. To further reduce test flakiness, he improved simulator version matching logic by comparing only major and minor versions, which minimized failures due to unavailable patch versions. Charles also enhanced diagnostic capabilities by adding exception logging to the ListCommand, increasing error visibility during local runs. His work leveraged Python and emphasized debugging, testing, and robust version management to improve test reliability.