anchor.diff:  { boost
   , fetchFromGitHub
  +, fetchpatch
   , installShellFiles
   , mkDerivationWith
   , muparser
  
positive.code:   stdenv = gcc8Stdenv;
  in
  
  # Doesn't build with gcc9
  mkDerivationWith stdenv.mkDerivation rec {
    pname = "librecad";
    version = "2.2.0-rc1";
  
negative.code: 
    patches = [
      ./fix_qt_5_11_build.patch
      (
        fetchpatch {
          # Fix missing app name and icon on Wayland.
          url = "https://github.com/LibreCAD/LibreCAD/commit/a17f8281093403f0c7c36996232665ed21906688.patch";
          sha256 = "1x46psh4bcx2hxck4l83ki43g1252vb033i2x94h4rpai9hww4d5";
        }
      )
    ];
  
    postPatch = ''
  