anchor.diff:          pure_analog      = .False.
           analog_regression= .True.
           pure_regression  = .False.
  +        debug            = .True.
           
           options%name = options%options_filename
  -        options%debug = .True.
           
           ! read namelists
           open(io_newunit(name_unit), file=trim(options%options_filename))
  
positive.code:                                          lat_name, lon_name, time_name,    &
                                           file_list, var_names,             &
                                           calendar, calendar_start_year,    &
                                           selected_time, time_indicies,     &
                                           interpolation_method, preloaded
          !defaults :
          nfiles      = -1
  
negative.code:         integer :: i, error
          character(len=MAXFILELENGTH) :: temporary_file
          
          if (module_debug) print*, "Reading: ",trim(filename)
          open(unit=io_newunit(file_unit), file=filename)
          i=0
          error=0
  