anchor.diff: -{ lib, stdenv, fetchurl, fetchpatch, ncurses, utmp, pam ? null }:
  +{ lib, stdenv, fetchurl, fetchpatch, autoreconfHook, ncurses, utmp, pam ? null }:
   
   stdenv.mkDerivation rec {
     pname = "screen";
  -  version = "4.8.0";
  +  version = "4.9.0";
   
     src = fetchurl {
       url = "mirror://gnu/screen/${pname}-${version}.tar.gz";
  -    sha256 = "18ascpjzsy70h6hk7wpg8zmzjwgdyrdr7c6z4pg5z4l9hhyv24bf";
  +    sha256 = "1x1hqy4h47i7hk85f779lkwkm7gkq8h8mxwd0znkh5adpf0m4czr";
     };
   
     configureFlags= [
  
positive.code:     "--enable-colors256"
    ];
  
    patches = [
      (fetchpatch {
        # Fixes denial of services in encoding.c, remove > 4.8.0
        name = "CVE-2021-26937.patch";
        url = "https://salsa.debian.org/debian/screen/-/raw/4f7494f943e8941528e651bd967fa3f837435140/debian/patches/99_CVE-2021-26937.patch";
        sha256 = "05f3p1c7s83nccwkhmavjzgaysxnvq41c7jffs31ra65kcpabqy0";
      })
    ] ++ lib.optional stdenv.hostPlatform.isMusl
      (fetchpatch {
        url = "https://gist.githubusercontent.com/yujinakayama/4608863/raw/76b9f89af5e5a2e97d9a0f36aac989fb56cf1447/gistfile1.diff";
        sha256 = "0f9bf83p8zdxaa1pr75jyf5g8xr3r8kv7cyzzbpraa1q4j15ss1p";
  
negative.code:            -e 's/^as_fn_error .. \("cannot run test program while cross compiling\)/$as_echo \1/g'
      ''; # "
  
    nativeBuildInputs = [
      autoreconfHook
    ];
    buildInputs = [
      ncurses
    ] ++ lib.optional stdenv.isLinux pam
      ++ lib.optional stdenv.isDarwin utmp;
  
    doCheck = true;
  
  