anchor.diff:    };
   
     nativeBuildInputs = [ pkgconfig ];
  -  buildInputs = [ coreutils db openssl pcre perl ];
  +  buildInputs = [ coreutils db openssl pcre perl ]
  +    ++ stdenv.lib.optional enableLDAP openldap;
   
     preBuild = ''
       sed '
  
positive.code:       s:^# \(RM_COMMAND\)=.*:\1=${coreutils}/bin/rm:
        s:^# \(TOUCH_COMMAND\)=.*:\1=${coreutils}/bin/touch:
        s:^# \(PERL_COMMAND\)=.*:\1=${perl}/bin/perl:
        #/^\s*#.*/d
        #/^\s*$/d
      ' < src/EDITME > Local/Makefile
  
negative.code: { coreutils, db, fetchurl, openldap, openssl, pcre, perl, pkgconfig, stdenv
  , enableLDAP ? false
  }:
  
  stdenv.mkDerivation rec {
    name = "exim-4.90";
  