anchor.diff:        default = {};
   
         example = literalExample ''
  -        { stdio = {
  -            text = '''
  -              # Needed by some programs.
  -              ln -sfn /proc/self/fd /dev/fd
  -              ln -sfn /proc/self/fd/0 /dev/stdin
  -              ln -sfn /proc/self/fd/1 /dev/stdout
  -              ln -sfn /proc/self/fd/2 /dev/stderr
  -            ''';
  -            deps = [];
  -          };
  +        { stdio.text =
  +          '''
  +            # Needed by some programs.
  +            ln -sfn /proc/self/fd /dev/fd
  +            ln -sfn /proc/self/fd/0 /dev/stdin
  +            ln -sfn /proc/self/fd/1 /dev/stdout
  +            ln -sfn /proc/self/fd/2 /dev/stderr
  +          ''';
           }
         '';
   
  
positive.code:         idempotent and fast.
        '';
  
        type = types.attrsOf types.unspecified;
  
        apply = set: {
          script = ''
  
negative.code:         idempotent and fast.
        '';
  
        type = types.attrsOf scriptType;
  
        apply = set: {
          script =
  