anchor.diff:  { stdenv
   , fetchurl
  +, lib
   }:
   
   let
  -  inherit (stdenv.lib)
  +  inherit (lib)
       elem
       optionals
       platforms;
   
  -  version = "4.15";
  +  version = "4.16";
   
     baseUrls = [
       "https://ftp.mozilla.org/pub/mozilla.org/nspr/releases/v${version}/src"
  
positive.code:     };
    };
  
    meta = with stdenv.lib; {
      homepage = http://www.mozilla.org/projects/nspr/;
      description = "Netscape Portable Runtime, a platform-neutral API for system-level and libc-like functions";
      maintainers = with maintainers; [
  
negative.code:   src = fetchurl {
      urls = map (n: "${n}/nspr-${version}.tar.gz") baseUrls;
      hashOutput = false;
      sha256 = "9b3102d97665504aeee73363c11a21c062ad67a2522242368b7f019f96a53cd1";
    };
  
    prePatch = ''
  