the Cargo.nix file is outdated. And I am unable to update it: https://github.com/kolloch/crate2nix/issues/168

You probably need to patch the following segment of Cargo.nix in flake.nix:

      "crossbeam-utils" = rec {
        crateName = "crossbeam-utils";
        version = "0.8.2";
        edition = "2018";
        sha256 = "1qqzffa93m9mf8s8kj5mmn93dh6hyakl4y3axdn5m3szhclg7s5s";
        authors = [
          "The Crossbeam Project Developers"
        ];
        dependencies = [
          {
            name = "cfg-if";
            packageId = "cfg-if 1.0.0";
          }
          {
            name = "lazy_static";
            packageId = "lazy_static";
            optional = true;
          }
          {
            name = "loom";
            packageId = "loom";
            # the following line fails with the following trace: https://gist.github.com/zseri/44eb7052e9634e2761e459272eab05c4
            # alternatively, you could set target.crossbeam_loom = false;
            target = { target, features }: target."crossbeam_loom";
          }
        ];
        buildDependencies = [
          {
            name = "autocfg";
            packageId = "autocfg";
          }
        ];
        features = {
          "default" = [ "std" ];
          "std" = [ "lazy_static" ];
        };
        resolvedDefaultFeatures = [ "default" "lazy_static" "std" ];
      };