error: Nixpkgs 26.11 has dropped support for x86_64-darwin.

The 26.05 stable branch still supports x86_64-darwin, and will
receive security fixes until the end of 2026. If you use channels,
you can switch to 26.05 as follows:

    $ sudo nix-channel --add https://nixos.org/channels/nixpkgs-26.05-darwin nixpkgs
    $ sudo nix-channel --update

If this doesn’t work, you may need to run:

    # Lack of sudo is deliberate:
    $ nix-channel --remove nixpkgs

If you use flakes, switch your flake input:

    inputs.nixpkgs = {
      url = "github:NixOS/nixpkgs/nixpkgs-26.05-darwin";
    };

See the release notes for more information and alternatives:

  https://nixos.org/manual/nixpkgs/unstable/release-notes#x86_64-darwin-26.11

       at /nix/store/rhsxvv1380jmchb5p3a43d24mhlmp2ry-source/lib/trivial.nix:1003:37
       … while calling the 'throw' builtin at /nix/store/rhsxvv1380jmchb5p3a43d24mhlmp2ry-source/lib/trivial.nix:1003:37
       … while calling anonymous lambda at /nix/store/rhsxvv1380jmchb5p3a43d24mhlmp2ry-source/lib/trivial.nix:1003:19
       … from call site at /nix/store/rhsxvv1380jmchb5p3a43d24mhlmp2ry-source/pkgs/top-level/default.nix:113:9
       … while calling anonymous lambda at /nix/store/rhsxvv1380jmchb5p3a43d24mhlmp2ry-source/lib/trivial.nix:982:40
       … from call site at /nix/store/rhsxvv1380jmchb5p3a43d24mhlmp2ry-source/pkgs/top-level/default.nix:108:6
       … while calling anonymous lambda at /nix/store/rhsxvv1380jmchb5p3a43d24mhlmp2ry-source/pkgs/top-level/default.nix:21:1
       … from call site at /nix/store/rhsxvv1380jmchb5p3a43d24mhlmp2ry-source/pkgs/top-level/impure.nix:55:1
       … while calling anonymous lambda at /nix/store/rhsxvv1380jmchb5p3a43d24mhlmp2ry-source/pkgs/top-level/impure.nix:12:1
       … from call site at /nix/store/rhsxvv1380jmchb5p3a43d24mhlmp2ry-source/flake.nix:234:12
       … while calling anonymous lambda at /nix/store/rhsxvv1380jmchb5p3a43d24mhlmp2ry-source/flake.nix:233:11
       … from call site at /nix/store/rhsxvv1380jmchb5p3a43d24mhlmp2ry-source/lib/attrsets.nix:1343:17
       … while evaluating the attribute 'legacyPackages.x86_64-darwin' at /nix/store/rhsxvv1380jmchb5p3a43d24mhlmp2ry-source/lib/attrsets.nix:1343:9
       … while calling anonymous lambda at /nix/store/6xr58mfvs42ixw6428x3vm9l5h88l2z7-source/modules/transposition.nix:115:20
       … while evaluating the attribute 'value' at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/types.nix:969:11
       … while evaluating definitions from `/nix/store/6xr58mfvs42ixw6428x3vm9l5h88l2z7-source/modules/transposition.nix':
       … while calling the '__addErrorContext' builtin at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1233:12
       … while evaluating the attribute 'optionalValue.value' at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1342:5
       … while calling anonymous lambda at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/types.nix:1029:18
       … while evaluating the attribute 'nixpkgs.legacyPackages'
       … while calling the '__seq' builtin at /nix/store/6xr58mfvs42ixw6428x3vm9l5h88l2z7-source/modules/nixpkgs.nix:19:11
       … while evaluating the attribute 'value.content' at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1600:22
       … while evaluating the attribute 'value._type' at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1458:67
       … while calling anonymous lambda at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1264:21
       … from call site at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1264:16
       … while calling the '__any' builtin at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1264:16
       … while evaluating the attribute 'values' at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1270:11
       … while evaluating the attribute 'optionalValue.value' at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1342:5
       … while calling anonymous lambda at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/types.nix:1029:18
       … while evaluating the attribute '_module.args.pkgs'
       … noting that argument `pkgs` is not externally provided, so querying `_module.args` instead, requiring `config`
       … while calling the '__addErrorContext' builtin at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:744:28
       … while evaluating the module argument `pkgs' in ":anon-11:anon-1":
       … while calling the '__addErrorContext' builtin at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:743:9
       … while calling anonymous lambda at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:742:15
       … while evaluating the attribute 'value' at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/types.nix:969:11
       … while evaluating definitions from `/nix/store/i90wf5n9gnalfkc9nzla52xmvwmhdkp9-source/flake.nix, via option perSystem':
       … while calling the '__addErrorContext' builtin at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1233:12
       … while evaluating the attribute 'optionalValue.value' at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1342:5
       … while calling anonymous lambda at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/types.nix:1029:18
       … while evaluating the attribute 'value' at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/types.nix:969:11
       … while evaluating definitions from `/nix/store/6xr58mfvs42ixw6428x3vm9l5h88l2z7-source/modules/transposition.nix':
       … while calling the '__addErrorContext' builtin at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1233:12
       … while evaluating the attribute 'optionalValue.value' at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1342:5
       … while calling anonymous lambda at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/types.nix:1029:18
       … while evaluating the attribute 'packages.nix-auth.overrideAttrs'
       … while evaluating the attribute 'value' at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/types.nix:969:11
       … while evaluating definitions from `/nix/store/i90wf5n9gnalfkc9nzla52xmvwmhdkp9-source/flake.nix, via option perSystem':
       … while calling the '__addErrorContext' builtin at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1233:12
       … while evaluating the attribute 'optionalValue.value' at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1342:5
       … while calling anonymous lambda at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/types.nix:1029:18
       … while evaluating the attribute 'value' at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/types.nix:969:11
       … while evaluating definitions from `/nix/store/6xr58mfvs42ixw6428x3vm9l5h88l2z7-source/modules/transposition.nix':
       … while calling the '__addErrorContext' builtin at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1233:12
       … while evaluating the attribute 'optionalValue.value' at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/modules.nix:1342:5
       … while calling anonymous lambda at /nix/store/f0r1xpd2wkbzcvn0bf1w1xvjkzpsyf1s-source/lib/types.nix:1029:18
       … while calling the '__isAttrs' builtin at «string»:25:9
       … while calling 'prune' at «string»:24:5