message: setting paralle level to 2 for arrow build
diff: @@ -56,7 +56,7 @@ if($ENV{PARALLEL_LEVEL})
  endif($ENV{PARALLEL_LEVEL})
  execute_process(
  - COMMAND ${CMAKE_COMMAND} --build .. -- ${PARALLEL_BUILD}
  + COMMAND ${CMAKE_COMMAND} --build .. -- -j 2
  RESULT_VARIABLE ARROW_BUILD
  WORKING_DIRECTORY ${ARROW_ROOT}/build)
  