$ /nix/store/imad8dvhp77h0pjbckp6wvmnyhp8dpgg-coreutils-9.8/bin/timeout --kill-after=15s 1800s /nix/store/mycbwkcm1jzjgsaiydvzib9phmzfz9vx-nix-2.31.1/bin/nix --extra-experimental-features nix-command --extra-experimental-features flakes --extra-substituters https://cache.nix-ci.com --extra-trusted-public-keys nix-ci-staging:Q5+aawDG0LPCgu1fP9e+9hktvsfSyvu/Xe5PvzTLRVs= --netrc-file /tmp/nix-ci-worker-33d007437decbbe0/nix-ci-cache-e107873c1acd8235/netrc --allow-import-from-derivation --print-build-logs flake show git+https://github.com/sellout/unison?ref=replace-nix-tooling&rev=bca81dee4c126e3d0332e7a427c789ea1257dbec --json --system x86_64-linux --post-build-hook /tmp/nix-ci-worker-33d007437decbbe0/build-hook-5c60fb3542352e02/nix-ci-nix-ci-upload.sh
evaluating ''...
error:
       … while evaluating the attribute 'packages'
         at /nix/store/nc5c97s1ybmkvydscqb7ms945lgqyr89-source/flake.nix:48:9:
           47|       assert pkgs.haskellPackages.weeder.version == versions.weeder; {
           48|         packages =
             |         ^
           49|           unisonPkgs

       … in the left operand of the update (//) operator
         at /nix/store/nc5c97s1ybmkvydscqb7ms945lgqyr89-source/flake.nix:50:11:
           49|           unisonPkgs
           50|           // {
             |           ^
           51|             default = unisonPkgs.unison-cli-main;

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: Cannot build '/nix/store/dc4q5xpghxbsswdgnrp1bjkn1s8jpy62-from-yaml-stack.yaml.drv'.
       Reason: required system or feature not available
       Required system: 'aarch64-darwin' with features {}
       Current system: 'x86_64-linux' with features {benchmark, big-parallel, kvm, nixos-test}