anchor.diff:            extra =
               ''
               <zodb_db main>
  -            mount-point /
  -            cache-size 30000
  -            <blobstorage>
  -                blob-dir /var/lib/zope2/plone01/blobstorage
  -                <filestorage>
  -                path /var/lib/zope2/plone01/filestorage/Data.fs
  -                </filestorage>
  -            </blobstorage>
  +              mount-point /
  +              cache-size 30000
  +              <blobstorage>
  +                  blob-dir /var/lib/zope2/plone01/blobstorage
  +                  <filestorage>
  +                  path /var/lib/zope2/plone01/filestorage/Data.fs
  +                  </filestorage>
  +              </blobstorage>
               </zodb_db>
               '';
   
  
positive.code:         default =
            ''
            <zodb_db main>
            mount-point /
            cache-size 30000
            <blobstorage>
                blob-dir /var/lib/zope2/${name}/blobstorage
                <filestorage>
                path /var/lib/zope2/${name}/filestorage/Data.fs
                </filestorage>
            </blobstorage>
            </zodb_db>
            '';
          type = types.string;
  
negative.code:           let
              interpreter = pkgs.writeScript "interpreter"
                ''
                import sys
  
                _interactive = True
                if len(sys.argv) > 1:
                    _options, _args = __import__("getopt").getopt(sys.argv[1:], 'ic:m:')
                    _interactive = False
                    for (_opt, _val) in _options:
                        if _opt == '-i':
                            _interactive = True
                        elif _opt == '-c':
                            exec _val
                        elif _opt == '-m':
                            sys.argv[1:] = _args
                            _args = []
                            __import__("runpy").run_module(
                                _val, {}, "__main__", alter_sys=True)
  
                    if _args:
                        sys.argv[:] = _args
                        __file__ = _args[0]
                        del _options, _args
                        execfile(__file__)
  
                if _interactive:
                    del _interactive
                    __import__("code").interact(banner="", local=globals())
                '';
              env = pkgs.buildEnv {
                name = "zope2-${name}-env";
  