Invisible Corruption: Why Local Docker Builds Fail With Stale Dependencies

This debugging journey reveals a critical blind spot for monorepo developers: local Docker builds can silently fail due to stale dependencies while CI succeeds, because CI always builds from a clean checkout. When pnpm was upgraded from version 9.x to 10.x, the workspace-level dependency structure became corrupted locally, yet CI remained unaffected thanks to its clean build environment. Understanding how to properly exclude workspace-level artifacts and regenerate dependencies after version upgrades is essential knowledge for preventing these invisible failures in containerized development.