{
  pkgs,
  lib,
  inputs,
  config ? {},
  ...
}: let
  system = pkgs.stdenv.hostPlatform.system;
  isJayLenovo = (config.networking.hostName or null) == "jay-lenovo";
  inputPackageOrNull = inputName: packageName: let
    input = inputs.${inputName} or null;
    packages =
      if input == null
      then null
      else input.packages or null;
    systemPackages =
      if packages == null
      then null
      else packages.${system} or null;
  in
    if systemPackages == null
    then null
    else systemPackages.${packageName} or null;

  git-blame-rank = inputs.git-blame-rank.packages.${system}.default.overrideAttrs (old: {
    env =
      (old.env or {})
      // {
        CARGO_BUILD_JOBS = "1";
      };
  });
  ccusage-fleet = pkgs.callPackage ../packages/ccusage-fleet.nix {
    src = inputs.ccusage-fleet;
  };
  gmcli = inputPackageOrNull "gmcli" "default";
  keepbook = inputs.keepbook.packages.${system}.keepbook.overrideAttrs (_: {
    # Upstream checks currently depend on TS artifacts that are not built in Nix.
    doCheck = false;
  });

  commonPkgs = lib.filter (pkg: lib.meta.availableOn pkgs.stdenv.hostPlatform pkg) ((with pkgs; [
      automake
      bento4
      bind
      binutils
      btop
      cachix
      bubblewrap
      cmake
      ccusage-fleet
      dex
      direnv
      fd
      ffmpeg
      file
      gawk
      gcc
      gh
      git-fame
      git-blame-rank
      git-lfs
      git-sync
      git
      gnumake
      home-manager
      htop
      ispell
      jq
      just
      keepbook
      lsof
      magic-wormhole-rs
      ncdu
      nodejs
      fastfetch
      neovim
      nix-index
      nix-search-cli
      pass
      patchelf
      pstree
      rclone
      ripgrep
      skim
      tmux
      zellij
      unzip
      wget
      xkcdpass
      yubikey-manager
    ])
    ++ lib.optionals (!isJayLenovo) [pkgs.bazel]
    ++ lib.optionals (gmcli != null) [gmcli]
    ++ lib.optionals (builtins.hasAttr "git-sync-rs" pkgs) [pkgs.git-sync-rs]);

  linuxOnly = with pkgs; [
    dex
    dpkg
    efibootmgr
    emacs-auto
    gparted
    inotify-tools
    iotop
    lshw
    mesa-demos
    pciutils
    pulseaudio
    python-with-my-packages
    runc
    sshfs
    sysz
    gdb
    gitFull
    udiskie
    usbutils
    tzupdate
    wl-clipboard
  ];

  darwinOnly = with pkgs; [
    emacs
  ];
in {
  nixpkgs.config.allowBroken = true;

  # Centralize cargo's intermediate build artifacts (deps, incremental caches,
  # fingerprints — the bulk of target-dir bloat) under
  # ~/.cargo/build/<workspace-path-hash>, so deleting a worktree doesn't strand
  # gigabytes and cleanup has one place to prune. Final artifacts still land in
  # each project's target/.
  environment.variables.CARGO_BUILD_BUILD_DIR = "{cargo-cache-home}/build/{workspace-path-hash}";

  environment.systemPackages =
    commonPkgs
    ++ lib.optionals pkgs.stdenv.isLinux linuxOnly
    ++ lib.optionals pkgs.stdenv.isDarwin darwinOnly;
}