Developed an environment-variable-based build control feature for the uv CLI in the luanfujun/uv repository, focusing on improving build efficiency and developer workflow. Leveraging Rust for CLI development and environment configuration, the work introduced UV_NO_BUILD and UV_NO_BUILD_PACKAGE variables, allowing users to skip building source distributions globally or for specific packages. This approach provided granular control over the build process, reducing unnecessary packaging during continuous integration and local development. The implementation addressed the need for selective builds, streamlining CI pipelines and minimizing redundant workload for developers. No bugs were fixed during this period, with efforts concentrated on this targeted feature enhancement.