anchor.diff:  
     sources = {
       "stable" = {
  -      version = "1.2.1";
  -      multihash = "QmT3msAH9XUDrWe43kP9Mpw47y6tmKBTrXmudNhXpKTji3";
  -      sha256 = "cfafd339ccd9c5ef8d6ab15d7e1a412c054bf4cb4ecbbbcc78c12ef2def70732";
  +      version = "1.3";
  +      multihash = "QmZ26cTAXDkHJhj1ABJoUUUh1TN7SmzYQpuqenzTukAo9x";
  +      sha256 = "4f3d69aefdf2dbaf9825408e452a8a414ffc60494c70633560700398820dc550";
       };
       "head" = {
         fetchzipversion = 5;
  
positive.code:   configureFlags = [
      "--disable-maintainer-mode"
      "--${boolEn fixedPoint}-fixed-point"
      "--disable-fixed-point-debug"
      "--${boolEn (!fixedPoint)}-float-api"
      # non-Opus modes, e.g. 44.1 kHz & 2^n frames
      "--enable-custom-modes"
      # Requires IEEE 754 floating point
      "--enable-float-approx"
      "--enable-asm"
      "--enable-rtcd"
      # Enable intrinsics optimizations for ARM & X86
      "--${boolEn (
        (elem targetSystem platforms.arm-all)
        || (elem targetSystem platforms.x86-all))}-intrinsics"
      "--disable-assertions"
      "--disable-fuzzing"
      "--enable-ambisonics"
      "--disable-doc"
      "--disable-extra-programs"
      "--enable-update-draft"
      #--with-NE10
    ];
  
    passthru = {
  
negative.code:         outputHash
          outputHashAlgo
          urls;
        failEarly = true;
        fullOpts = {
          md5Urls = map (n: "${n}/MD5SUMS") releaseUrls;
          sha1Urls = map (n: "${n}/SHA1SUMS") releaseUrls;
          sha256Urls = map (n: "${n}/SHA256SUMS.txt") releaseUrls;
        };
      };
    };
  
  