Worked on improving the reliability of the build system for the tuist/tuist repository by addressing environment-specific build failures related to Swift include path resolution. Focused on build system configuration and Xcode toolchain management, the developer replaced hardcoded Xcode include paths with the TOOLCHAIN_DIR variable, ensuring that Swift Package Manager manifest API paths resolve correctly across different Xcode and toolchain installations. This change, implemented in Swift, fixed a persistent bug that caused build failures in diverse development environments and improved CI reliability. The work demonstrated a targeted approach to cross-environment compatibility and maintainability within the project’s build infrastructure.