message: Let DataMan_ROOT_DIR be specified by either a CMake or Env variable
diff: # You can also set the following variable to help guide the search:
  # DataMan_ROOT_DIR - The install prefix for DataMan containing the
  # include and lib folders
  +# Note: this can be set as a CMake variable or an
  +# environment variable. If specified as a CMake
  +# variable, it will override any setting specified
  +# as an environment variable.
  if(NOT DataMan_FOUND)
  + if((NOT DataMan_ROOT_DIR) AND (NOT (ENV{DataMan_ROOT_DIR} STREQUAL "")))
  + set(DataMan_ROOT_DIR "$ENV{DataMan_ROOT_DIR}")
  + endif()
  +
  # Search for the core libraries
  if(DataMan_ROOT_DIR)
  # If a root directory is specified, then don't look anywhere else
  