anchor.diff:        { name = "mysqli"; configureFlags = [ "--with-mysqli=mysqlnd" "--with-mysql-sock=/run/mysqld/mysqld.sock" ]; }
         # oci8 (7.4, 7.3, 7.2)
         # odbc (7.4, 7.3, 7.2)
  -      { name = "opcache"; buildInputs = [ pcre' ]; }
  +      { name = "opcache"; buildInputs = [ pcre' ]; zendExtension = true; }
         { name = "pcntl"; }
         { name = "pdo"; }
         { name = "pdo_dblib";
  
positive.code: 
        enableParallelBuilding = true;
        nativeBuildInputs = [ php autoconf pkgconfig re2c ];
        inherit configureFlags buildInputs;
  
        preConfigure = "phpize";
  
  
negative.code:     # Name passed is the name of the extension and is automatically used
      # to add the configureFlag "--enable-${name}", which can be overriden.
      #
      # Build inputs is used for extra deps that may be needed. And zendExtension
      # will mark the extension as a zend extension or not.
      mkExtension = {
        name
        , configureFlags ? [ "--enable-${name}" ]
        , buildInputs ? []
        , zendExtension ? false
        , ...
      }: stdenv.mkDerivation {
        pname = "php-ext-${name}";
  