anchor.diff:  , echo ? false
   , ngx_lua ? false
   , set_misc ? false
  +, fluent ? false
   }:
   
   with stdenv.lib;
  
positive.code:     sha256 = "1bd1isacsiay73nc2jlp0wky32l42a3sjskvfa1082l12g0p1x39";
    };
  
  in
  
  stdenv.mkDerivation rec {
  
negative.code:     ++ optional echo "--add-module=${echo-ext}"
      ++ optional ngx_lua "--add-module=${develkit-ext} --add-module=${lua-ext}"
      ++ optional set_misc "--add-module=${set-misc-ext}"
      ++ optional (elem stdenv.system (with platforms; linux ++ freebsd)) "--with-file-aio"
      ++ optional fluent "--add-module=${fluentd}";
  
  
    additionalFlags = optionalString stdenv.isDarwin "-Wno-error=deprecated-declarations -Wno-error=conditional-uninitialized";
  