Variables in question:
AZURECIREPO TITLEBARFORMATIDLE TITLEBARFORMATRUNNING DISPLAYVERSION

CMakeModules/GenerateSCMRev.cmake has some logic that looks at BUILD_REPOSITORY variable inside CMake

src/common/CMakeLists.txt has some logic that takes some items from environment variables and
 sets variables inside CMake

This is the whole section at the moment.

    if (DEFINED ENV{AZURECIREPO})
      set(BUILD_REPOSITORY $ENV{AZURECIREPO})
    endif()
    if (DEFINED ENV{TITLEBARFORMATIDLE})
      set(TITLE_BAR_FORMAT_IDLE $ENV{TITLEBARFORMATIDLE})
    endif ()
    if (DEFINED ENV{TITLEBARFORMATRUNNING})
      set(TITLE_BAR_FORMAT_RUNNING $ENV{TITLEBARFORMATRUNNING})
    endif ()
    if (DEFINED ENV{DISPLAYVERSION})
      set(DISPLAY_VERSION $ENV{DISPLAYVERSION})
    endif ()