Worked on the llvm/llvm-project repository to address a critical build system issue involving CMake and complex path configurations. Focused on improving the handling of the CMAKE_PREFIX_PATH variable when passed via the command line, the developer implemented robust escaping for semicolon separators to ensure CMake correctly interprets path lists. This targeted bug fix enhanced build reliability in environments with nested or intricate paths, reducing a common source of build failures. The work was carried out using CMake and build system expertise, with careful attention to patch validation and code review, and did not introduce any user-facing API changes during the process.