anchor.diff:  substitute_env(FieldAndDefaultAndRemainder) ->
       case get_field_and_default(FieldAndDefaultAndRemainder) of 
   	{ error, Reason, Rem } ->
  +	    ?warning("Could not retrieve $env field from: ~p: ~p", 
  +		     [ FieldAndDefaultAndRemainder, Reason ]),
   	    { lists:reverse("ERR:"++atom_to_list(Reason)), Rem };
   
   	{ ok, FieldName, Default, Rem } ->
  
positive.code: substitute_file(FieldAndDefaultAndRemainder) ->
      case get_field_and_default(FieldAndDefaultAndRemainder) of 
  	{ error, Reason, Rem } ->
  	    { lists:reverse("ERR:"++atom_to_list(Reason)), Rem };
  
  	{ ok, FileName, Default, Rem } ->
  
negative.code: 
  -module(rvi_config).
  
  -include_lib("lager/include/log.hrl").
  
  
  -export([setup_substitution/1]).
  -export([substitute/2]).
  -define(BOOT_PARAMS, "/proc/cmdline").
  
  	
  
  %% We hit the end of the list before we saw a closing paranthesis.
  get_default(_FieldName, [], Acc) ->
  