CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT — CMake 3.24.1 Documentation

# CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT

New in version 3.7.1.

CMake sets this variable to a `TRUE` value when the `CMAKE_INSTALL_PREFIX` has just been initialized to its default value, typically on the first run of CMake within a new build tree. This can be used by project code to change the default without overriding a user-provided value:

    if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
      set(CMAKE_INSTALL_PREFIX "/my/default" CACHE PATH "..." FORCE)
    endif()