anchor.diff:          outputHash
           outputHashAlgo
           urls;
  -      md5Urls = map (n: "${n}/MD5SUMS") releaseUrls;
  -      sha1Urls = map (n: "${n}/SHA1SUMS") releaseUrls;
  -      sha256Urls = map (n: "${n}/SHA256SUMS.txt") releaseUrls;
         failEarly = true;
  +      fullOpts = {
  +        md5Urls = map (n: "${n}/MD5SUMS") releaseUrls;
  +        sha1Urls = map (n: "${n}/SHA1SUMS") releaseUrls;
  +        sha256Urls = map (n: "${n}/SHA256SUMS.txt") releaseUrls;
  +      };
       };
     };
   
  
positive.code: 
    sources = {
      "stable" = {
        version = "1.2.1";
        multihash = "QmT3msAH9XUDrWe43kP9Mpw47y6tmKBTrXmudNhXpKTji3";
        sha256 = "cfafd339ccd9c5ef8d6ab15d7e1a412c054bf4cb4ecbbbcc78c12ef2def70732";
      };
      "head" = {
        fetchzipversion = 5;
  
negative.code:   configureFlags = [
      "--disable-maintainer-mode"
      "--${boolEn fixedPoint}-fixed-point"
      "--${boolEn (!fixedPoint)}-float-api"
      # non-Opus modes, e.g. 44.1 kHz & 2^n frames
      "--enable-custom-modes"
      "--enable-float-approx"
      "--disable-doc"
      "--disable-extra-programs"
    ];
  
    passthru = {
  