anchor.diff:      aarch64 = "arm64";
   
     in {
  +    "1.24.3-x86_64-darwin" = fetchurl {
  +      url = "${base}/${stable_version}/release/${version}/sdk/dartsdk-macos-${x86_64}-release.zip";
  +      sha256 = "1n4cq4jrms4j0yl54b3w14agcgy8dbipv5788jziwk8q06a8c69l";
  +    };
       "1.24.3-x86_64-linux" = fetchurl {
         url = "${base}/${stable_version}/release/${version}/sdk/dartsdk-linux-${x86_64}-release.zip";
         sha256 = "16sm02wbkj328ni0z1z4n4msi12lb8ijxzmbbfamvg766mycj8z3";
  
positive.code:     "2.9.0-4.0.dev-aarch64-linux" = fetchurl {
        url = "${base}/${dev_version}/release/${version}/sdk/dartsdk-linux-${aarch64}-release.zip";
        sha256 = "1x6mlmc4hccmx42k7srhma18faxpxvghjwqahna80508rdpljwgc";
      };
      "2.11.0-161.0.dev-x86_64-linux" = fetchurl {
        url = "${base}/${dev_version}/release/${version}/sdk/dartsdk-linux-${x86_64}-release.zip";
  
negative.code:     "1.24.3-aarch64-linux" = fetchurl {
        url = "${base}/${stable_version}/release/${version}/sdk/dartsdk-linux-${aarch64}-release.zip";
        sha256 = "1p5bn04gr91chcszgmw5ng8mlzgwsrdr2v7k7ppwr1slkx97fsrh";
      };
      "2.7.2-x86_64-darwin" = fetchurl {
        url = "${base}/${stable_version}/release/${version}/sdk/dartsdk-macos-${x86_64}-release.zip";
        sha256 = "111zl075qdk2zd4d4mmfkn30jmzsri9nq3nspnmc2l245gdq34jj";
      };
      "2.7.2-x86_64-linux" = fetchurl {
        url = "${base}/${stable_version}/release/${version}/sdk/dartsdk-linux-${x86_64}-release.zip";
  