anchor.diff:          ++ optional bz2Support bzip2
           ++ optional (mssqlSupport && !stdenv.isDarwin) freetds
           ++ optional sodiumSupport libsodium
  -        ++ optional tidySupport html-tidy;
  +        ++ optional tidySupport html-tidy
  +        ++ optional argon2Support libargon2;
   
         CXXFLAGS = optional stdenv.cc.isClang "-std=c++11";
   
  
positive.code: , mysql, libxml2, readline, zlib, curl, postgresql, gettext
  , openssl, pcre, pkgconfig, sqlite, config, libjpeg, libpng, freetype
  , libxslt, libmcrypt, bzip2, icu, openldap, cyrus_sasl, libmhash, freetds
  , uwimap, pam, gmp, apacheHttpd, libiconv, systemd, libsodium, html-tidy
  }:
  
  with lib;
  
negative.code:   , calendarSupport ? config.php.calendar or true
    , sodiumSupport ? (config.php.sodium or true) && (versionAtLeast version "7.2")
    , tidySupport ? (config.php.tidy or false)
    , argon2Support ? (config.php.argon2 or true) && (versionAtLeast version "7.2")
    }:
  
      let
  