anchor.diff:  assert enablePostgreSQLDatabase -> postgresql != null;
   assert enableSubversionRepository -> subversion != null;
   assert enableEjabberdDump -> ejabberd != null;
  -assert enableMongoDatabase -> mongodb != null;
  +assert enableMongoDatabase -> (mongodb != null && mongodb-tools != null);
   
   stdenv.mkDerivation {
     name = "dysnomia-0.4";
  
positive.code: { stdenv, fetchurl
  , ejabberd ? null, mysql ? null, postgresql ? null, subversion ? null, mongodb ? null
  , enableApacheWebApplication ? false
  , enableAxis2WebService ? false
  , enableEjabberdDump ? false
  
negative.code:     ++ stdenv.lib.optional enableMySQLDatabase mysql.out
      ++ stdenv.lib.optional enablePostgreSQLDatabase postgresql
      ++ stdenv.lib.optional enableSubversionRepository subversion
      ++ stdenv.lib.optional enableMongoDatabase mongodb
      ++ stdenv.lib.optional enableMongoDatabase mongodb-tools;
  
    meta = {
      description = "Automated deployment of mutable components and services for Disnix";
  