anchor.diff:  { stdenv, fetchFromGitHub, cmake, makeWrapper, pkgconfig
   , avahi, dbus, gettext, git, gnutar, gzip, bzip2, ffmpeg_3, libiconv, openssl, python
  -, which, zlib }:
  +, v4l-utils, which, zlib }:
   
   let
     version = "4.2.8";
   
  +  dtv-scan-tables = stdenv.mkDerivation {
  +    pname = "dtv-scan-tables";
  +    version = "2020-05-18";
  +    src = fetchFromGitHub {
  +      owner = "tvheadend";
  +      repo = "dtv-scan-tables";
  +      rev = "e3138a506a064f6dfd0639d69f383e8e576609da";
  +      sha256 = "19ac9ds3rfc2xrqcywsbd1iwcpv7vmql7gp01iikxkzcgm2g2b6w";
  +    };
  +    nativeBuildInputs = [ v4l-utils ];
  +    installFlags = [ "DATADIR=$(out)" ];
  +  };
   in stdenv.mkDerivation {
     pname = "tvheadend";
     inherit version;
  
positive.code: 
      substituteInPlace src/config.c \
        --replace /usr/bin/tar ${gnutar}/bin/tar
  
      # the version detection script `support/version` reads this file if it
      # exists, so let's just use that
  
negative.code:   NIX_CFLAGS_COMPILE = [ "-Wno-error=format-truncation" "-Wno-error=stringop-truncation" ];
  
    # disable dvbscan, as having it enabled causes a network download which
    # cannot happen during build.  We now include the dtv-scan-tables ourselves
    configureFlags = [
      "--disable-dvbscan"
      "--disable-bintray_cache"
  