anchor.diff:  { stdenv, fetchurl
  -, ejabberd ? null, mysql ? null, postgresql ? null, subversion ? null
  +, ejabberd ? null, mysql ? null, postgresql ? null, subversion ? null, mongodb ? null
   , enableApacheWebApplication ? false
   , enableAxis2WebService ? false
   , enableEjabberdDump ? false
  
positive.code: assert enablePostgreSQLDatabase -> postgresql != null;
  assert enableSubversionRepository -> subversion != null;
  assert enableEjabberdDump -> ejabberd != null;
  
  stdenv.mkDerivation {
    name = "dysnomia-0.3pre7c81cc254a0f6966dd9ac55f945c458b45b3d428.tar.gz";
    src = fetchurl {
      url = http://hydra.nixos.org/build/5613342/download/1/dysnomia-0.3pre7c81cc254a0f6966dd9ac55f945c458b45b3d428.tar.gz;
      sha256 = "0ll09vh94ygqkncq4ddb62s4c84n3pr5qy0gi1ywy0j30qk6zvsq";
    };
    
    preConfigure = if enableEjabberdDump then "export PATH=$PATH:${ejabberd}/sbin" else "";
  
negative.code:      ${if enablePostgreSQLDatabase then "--with-postgresql" else "--without-postgresql"}
       ${if enableSubversionRepository then "--with-subversion" else "--without-subversion"}
       ${if enableTomcatWebApplication then "--with-tomcat=${catalinaBaseDir}" else "--without-tomcat"}
       ${if enableMongoDatabase then "--with-mongodb" else "--without-mongodb"}
     '';
    
    buildInputs = []
      ++ stdenv.lib.optional enableEjabberdDump ejabberd
      ++ stdenv.lib.optional enableMySQLDatabase mysql
      ++ stdenv.lib.optional enablePostgreSQLDatabase postgresql
      ++ stdenv.lib.optional enableSubversionRepository subversion
      ++ stdenv.lib.optional enableMongoDatabase mongodb;
  
    meta = {
      description = "Automated deployment of mutable components and services for Disnix";
  