code: def CreateConfigHBuilder(env):
      
      action = SCons.Action.Action(_createConfigH,
                                   _stringConfigH)
      sconfigHBld = SCons.Builder.Builder(action=action)
      env.Append( BUILDERS={'SConfigHBuilder':sconfigHBld} )
      for k in list(_ac_config_hs.keys()):
          env.SConfigHBuilder(k, env.Value(_ac_config_hs[k]))
docs: Called if necessary just before the building targets phase begins.