error:
       … while evaluating the attribute 'hydraJobs'
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/outputs.nix:174:11:
          173|   inherit checks;
          174|   inherit hydraJobs;
             |           ^
          175| }

       … from call site
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/outputs.nix:145:12:
          144|
          145|   ciJobs = utils.flattenDerivationTree ":" nested-ci-jobs.${system};
             |            ^
          146|

       … while calling 'flattenDerivationTree'
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/utils.nix:7:38:
            6|   # Used in: `nix/outputs.nix` (to build `flattened-ci-jobs` and `ciJobs`).
            7|   flattenDerivationTree = separator: set:
             |                                      ^
            8|     let

       … while calling the 'listToAttrs' builtin
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/utils.nix:19:37:
           18|     in
           19|     assert lib.typeOf set == "set"; lib.listToAttrs (flatten "" set);
             |                                     ^
           20|

       … from call site
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/utils.nix:19:54:
           18|     in
           19|     assert lib.typeOf set == "set"; lib.listToAttrs (flatten "" set);
             |                                                      ^
           20|

       … while calling 'flatten'
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/utils.nix:12:23:
           11|
           12|       flatten = name: value:
             |                       ^
           13|         if lib.isDerivation value || lib.typeOf value != "set" then

       … while calling the 'concatLists' builtin
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/utils.nix:16:11:
           15|         else
           16|           lib.concatLists (lib.mapAttrsToList (recurse name) value);
             |           ^
           17|

       … while calling 'flatten'
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/utils.nix:12:23:
           11|
           12|       flatten = name: value:
             |                       ^
           13|         if lib.isDerivation value || lib.typeOf value != "set" then

       … while calling the 'concatLists' builtin
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/utils.nix:16:11:
           15|         else
           16|           lib.concatLists (lib.mapAttrsToList (recurse name) value);
             |           ^
           17|

       … while calling 'flatten'
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/utils.nix:12:23:
           11|
           12|       flatten = name: value:
             |                       ^
           13|         if lib.isDerivation value || lib.typeOf value != "set" then

       … while evaluating a branch condition
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/utils.nix:13:9:
           12|       flatten = name: value:
           13|         if lib.isDerivation value || lib.typeOf value != "set" then
             |         ^
           14|           [{ inherit name value; }]

       … in the left operand of the OR (||) operator
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/utils.nix:13:35:
           12|       flatten = name: value:
           13|         if lib.isDerivation value || lib.typeOf value != "set" then
             |                                   ^
           14|           [{ inherit name value; }]

       … from call site
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/utils.nix:13:12:
           12|       flatten = name: value:
           13|         if lib.isDerivation value || lib.typeOf value != "set" then
             |            ^
           14|           [{ inherit name value; }]

       … while calling 'isDerivation'
         at /nix/store/201v6s1hyhfb4m6flp3gqiva1yy23dvj-source/lib/attrsets.nix:1251:18:
         1250|   */
         1251|   isDerivation = value: value.type or null == "derivation";
             |                  ^
         1252|

       … while evaluating the attribute 'default.overrideAttrs'
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/outputs.nix:111:5:
          110|   devShells = rec {
          111|     default = ghc96;
             |     ^
          112|     ghc96 = mkShell "ghc96";

       … from call site
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/outputs.nix:112:13:
          111|     default = ghc96;
          112|     ghc96 = mkShell "ghc96";
             |             ^
          113|     ghc912 = mkShell "ghc912";

       … while calling 'mkShell'
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/outputs.nix:38:13:
           37|
           38|   mkShell = ghc: import ./shell.nix
             |             ^
           39|     { inherit inputs pkgs lib project agda-tools metatheory r-with-packages ghc mkFourmolu; };

       … from call site
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/outputs.nix:38:18:
           37|
           38|   mkShell = ghc: import ./shell.nix
             |                  ^
           39|     { inherit inputs pkgs lib project agda-tools metatheory r-with-packages ghc mkFourmolu; };

       … while calling anonymous lambda
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/shell.nix:3:1:
            2|
            3| { inputs, pkgs, lib, project, agda-tools, metatheory, r-with-packages, ghc, mkFourmolu }:
             | ^
            4|

       … while evaluating the attribute 'ghc96'
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/shell.nix:173:5:
          172|   shell = {
          173|     ghc96 = full-shell;
             |     ^
          174|     ghc912 = full-shell;

       … from call site
         at /nix/store/b2ygi0m16bfljiqfyn9spqnh7lmjdrdq-source/nix/shell.nix:138:16:
          137|   # Full developer shell with many tools.
          138|   full-shell = project.projectVariants.${ghc}.shellFor {
             |                ^
          139|     name = "plutus-shell-${ghc}";

       … while calling 'shellFor'
         at /nix/store/dv3igkb6xsm0h16zmhddry9an4bhc54k-source/overlays/haskell.nix:836:24:
          835|             #
          836|             shellFor = extraArgs: (appendModule { shell = extraArgs; }).shell;
             |                        ^
          837|             shell = shellFor' rawProject.args.shell.crossPlatforms;

       … while evaluating the attribute 'shell'
         at /nix/store/dv3igkb6xsm0h16zmhddry9an4bhc54k-source/overlays/haskell.nix:837:13:
          836|             shellFor = extraArgs: (appendModule { shell = extraArgs; }).shell;
          837|             shell = shellFor' rawProject.args.shell.crossPlatforms;
             |             ^
          838|             shellFor' = crossPlatforms:

       … from call site
         at /nix/store/dv3igkb6xsm0h16zmhddry9an4bhc54k-source/overlays/haskell.nix:837:21:
          836|             shellFor = extraArgs: (appendModule { shell = extraArgs; }).shell;
          837|             shell = shellFor' rawProject.args.shell.crossPlatforms;
             |                     ^
          838|             shellFor' = crossPlatforms:

       … while calling 'shellFor''
         at /nix/store/dv3igkb6xsm0h16zmhddry9an4bhc54k-source/overlays/haskell.nix:838:25:
          837|             shell = shellFor' rawProject.args.shell.crossPlatforms;
          838|             shellFor' = crossPlatforms:
             |                         ^
          839|               let

       … while evaluating the attribute 'hsPkgs.shellFor'
         at /nix/store/dv3igkb6xsm0h16zmhddry9an4bhc54k-source/overlays/haskell.nix:707:44:
          706|               project = addProjectAndPackageAttrs rec {
          707|                   inherit (pkg-set.config) hsPkgs;
             |                                            ^
          708|                   inherit pkg-set;

       … while evaluating a branch condition
         at /nix/store/dv3igkb6xsm0h16zmhddry9an4bhc54k-source/overlays/haskell.nix:676:25:
          675|                 else project;
          676|               pkg-set = if plan-pkgs ? configurationError
             |                         ^
          677|                 then {

       … while evaluating a branch condition
         at /nix/store/dv3igkb6xsm0h16zmhddry9an4bhc54k-source/overlays/haskell.nix:661:27:
          660|               callProjectResults = callCabalProjectToNix config;
          661|               plan-pkgs = if !builtins.pathExists (callProjectResults.projectNix + "/plan.json")
             |                           ^
          662|                 then

       … in the argument of the not operator
         at /nix/store/dv3igkb6xsm0h16zmhddry9an4bhc54k-source/overlays/haskell.nix:661:31:
          660|               callProjectResults = callCabalProjectToNix config;
          661|               plan-pkgs = if !builtins.pathExists (callProjectResults.projectNix + "/plan.json")
             |                               ^
          662|                 then

       … while calling the 'pathExists' builtin
         at /nix/store/dv3igkb6xsm0h16zmhddry9an4bhc54k-source/overlays/haskell.nix:661:31:
          660|               callProjectResults = callCabalProjectToNix config;
          661|               plan-pkgs = if !builtins.pathExists (callProjectResults.projectNix + "/plan.json")
             |                               ^
          662|                 then

       … while realising the context of path '/nix/store/nac4gl90mjf4cnlx16s473iv2sfbqzar-plutus-plan-to-nix-pkgs/plan.json'

       error: Cannot build '/nix/store/92rsailslfwfadv40cq5d1wasfrkj72a-plutus-plan-to-nix-pkgs.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/57lxha0vgd0j0z4v6ia3vammdhvf1kbr-plutus-plan-to-nix-pkgs-freeze
         /nix/store/nac4gl90mjf4cnlx16s473iv2sfbqzar-plutus-plan-to-nix-pkgs
       Last 17 log lines:
       > Ignoring ./doc/notes/fomega/package.yaml as ./doc/notes/fomega/fomega.cabal exists
       > Cloning into '/nix/var/nix/builds/nix-39671-3765551860/tmp.2LHLol6UoM/dist-newstyle/src/ff0s2p3jr_-4b2f6ee0e9a5e48ab766db94af63acf7b9786a753ecddf2b5bdf7780e28b6e4d'...
       > remote: Enumerating objects: 454, done.
       > remote: Counting objects: 100% (454/454), done.
       > remote: Compressing objects: 100% (416/416), done.
       > remote: Total 454 (delta 24), reused 0 (delta 0), pack-reused 0 (from 0)
       > Receiving objects: 100% (454/454), 1.27 MiB | 5.95 MiB/s, done.
       > Resolving deltas: 100% (24/24), done.
       > HEAD is now at 561b54f Minimal Repo For Haskell.Nix
       > Configuration is affected by the following files:
       > - cabal.project
       > Warning: The package list for 'hackage.haskell.org' is 20637 days old.
       > Run 'cabal update' to get the latest list of available packages.
       > Error: [Cabal-7159]
       > Latest known index-state for 'hackage.haskell.org' (2026-05-19T01:33:52Z) is older than the requested index-state (2026-06-22T23:30:49Z).
       > Run 'cabal update' or set the index-state to a value at or before 2026-05-19T01:33:52Z.
       >
       For full logs, run:
         nix log /nix/store/92rsailslfwfadv40cq5d1wasfrkj72a-plutus-plan-to-nix-pkgs.drv