anchor.diff: -{ lib, mkDerivation, callPackage, fetchurl, fetchpatch,
  +{ lib, mkDerivation, callPackage, fetchFromGitHub,
     guile_1_8, qtbase, xmodmap, which, freetype,
     libjpeg,
     sqlite,
  
positive.code: mkDerivation {
    name = "${pname}-${version}";
  
    src = fetchurl {
      url = "https://www.texmacs.org/Download/ftp/tmftp/source/TeXmacs-${version}-src.tar.gz";
      sha256 = "1zbl1ddhppgnn3j213jl1b9mn8zmwnknxiqswm25p4llj0mqcgna";
    };
  
    enableParallelBuilding = true;
  
negative.code: 
  let
    pname = "TeXmacs";
    version = "1.99.15";
    common = callPackage ./common.nix {
      inherit tex extraFonts chineseFonts japaneseFonts koreanFonts;
    };
  