macro(git_version_gen)

  include(FindGit)
  if (NOT GIT_FOUND)
    message(FATAL_ERROR "This is not a git repository")
  endif ()

  find_program(TAIL "tail")
  mark_as_advanced(TAIL)
  if (${TAIL} STREQUAL "")
    message(FATAL_ERROR "Cannot find the tail executable")
  endif ()

  execute_process(
    COMMAND ${GIT_EXECUTABLE} tag -l -n0
    COMMAND ${TAIL} -n 1
    WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
    OUTPUT_VARIABLE _git_tag
    RESULT_VARIABLE _git_result
    OUTPUT_STRIP_TRAILING_WHITESPACE)
  if (NOT ${_git_result} EQUAL 0)
    message(FATAL_ERROR "Cannot fetch repository tag")
  endif ()
  message(STATUS "Repository tag is: ${_git_tag}")

  string(REGEX REPLACE
    "^([0-9]+)\\..*" "\\1"
    _version_major "${_git_tag}")
  string(REGEX REPLACE
    "^[0-9]+\\.([0-9]+)\\..*" "\\1"
    _version_minor "${_git_tag}")
  string(REGEX REPLACE
    "^[0-9]+\\.[0-9]+\\.([0-9]+)" "\\1"
    _version_patch "${_git_tag}")

  set(PACKAGE_VERSION_MAJOR "${_version_major}")
  set(PACKAGE_VERSION_MINOR "${_version_minor}")
  set(PACKAGE_VERSION_PATCH "${_version_patch}")

endmacro(git_version_gen)