anchor.diff:  { stdenv, fetchurl
  -, ejabberd ? null, mysql ? null, postgresql ? null, subversion ? null, mongodb ? null, mongodb-tools ? null
  +, ejabberd ? null, mysql ? null, postgresql ? null, subversion ? null, mongodb ? null, mongodb-tools ? null, influxdb ? null
   , enableApacheWebApplication ? false
   , enableAxis2WebService ? false
   , enableEjabberdDump ? false
  
positive.code:      (if enableSubversionRepository then "--with-subversion" else "--without-subversion")
       (if enableTomcatWebApplication then "--with-tomcat=${catalinaBaseDir}" else "--without-tomcat")
       (if enableMongoDatabase then "--with-mongodb" else "--without-mongodb")
       "--with-job-template=${jobTemplate}"
     ];
  
  
negative.code: , enableSubversionRepository ? false
  , enableTomcatWebApplication ? false
  , enableMongoDatabase ? false
  , enableInfluxDatabase ? false
  , catalinaBaseDir ? "/var/tomcat"
  , jobTemplate ? "systemd"
  , getopt
  