anchor.diff:  { stdenv, fetchurl, makeWrapper
  -, boehmgc, libatomic_ops, pcre, libevent, libiconv, llvm, clang }:
  +, boehmgc, libatomic_ops, pcre, libevent, libiconv, llvm, clang, which }:
   
   stdenv.mkDerivation rec {
     name = "crystal-${version}";
  -  version = "0.25.1";
  +  version = "0.26.0";
   
     src = fetchurl {
       url = "https://github.com/crystal-lang/crystal/archive/${version}.tar.gz";
  -    sha256 = "1ikzly6vs28ilqvqm4kxzhqs8mp6l4l344rhak63dav7vv97nnlv";
  +    sha256 = "18vv47xvnf3hl5js5sk58wj2khqq36kcs851i3lgr0ji7m0g3379";
     };
   
  -  prebuiltName = "crystal-0.25.1-1";
  +  prebuiltName = "crystal-0.26.0-1";
     prebuiltSrc = let arch = {
       "x86_64-linux" = "linux-x86_64";
       "i686-linux" = "linux-i686";
       "x86_64-darwin" = "darwin-x86_64";
     }."${stdenv.system}" or (throw "system ${stdenv.system} not supported");
     in fetchurl {
  -    url = "https://github.com/crystal-lang/crystal/releases/download/0.25.1/${prebuiltName}-${arch}.tar.gz";
  +    url = "https://github.com/crystal-lang/crystal/releases/download/0.26.0/${prebuiltName}-${arch}.tar.gz";
       sha256 = {
  -      "x86_64-linux" = "0zjmbvbhi11p7s99jmvb3pac6zzsr792bxcfanrx503fjxxafgll";
  -      "i686-linux" = "0i0hgsq7xa53594blqw5qi6jrqja18spifmalg7df2mj3h13h3pz";
  -      "x86_64-darwin" = "1h369hzis1cigxbb6fgpahyq4d13gfgjc6adf300zc38yh8rvyy0";
  +      "x86_64-linux" = "1xban102yiiwmlklxvn3xp3q546bp8hlxxpakayajkhhnpl6yv45";
  +      "i686-linux" = "1igspf1lrv7wpmz0pfrkbx8m1ykvnv4zhic53cav4nicppm2v0ic";
  +      "x86_64-darwin" = "0hzc65ccajr0yhmvi5vbdgbzbp1gbjy56da24ds3zwwkam1ddk0k";
       }."${stdenv.system}";
     };
   
  
positive.code:     description = "A compiled language with Ruby like syntax and type inference";
      homepage = https://crystal-lang.org/;
      license = stdenv.lib.licenses.asl20;
      maintainers = with stdenv.lib.maintainers; [ sifmelcara david50407 ];
      platforms = [ "x86_64-linux" "i686-linux" "x86_64-darwin" ];
    };
  }
  
negative.code:     libiconv
    ];
  
    nativeBuildInputs = [ which makeWrapper ];
  
    buildInputs = libs ++ [ llvm ];
  
  