message: COMP: fix unused variable warning
diff: @@ -64,7 +64,9 @@ const char IGNORE_OUTPUT[] = ".*";
  namespace
  {
  +#if defined( AXOM_USE_MPI ) && defined( AXOM_USE_MPI3 )
  constexpr bool USE_MPI3_SHARED_MEMORY = true;
  +#endif
  /*!
  * \brief Generate a mesh of 4 triangles along the XY plane.
  