pkgs: migrate to nilla

pkgs/default.nix

@@ -1,35 +1,52 @@
-{ inputs, ... }:
+let
+  systems = [
+    "x86_64-linux"
+    "aarch64-linux"
+    "aarch64-darwin"
+  ];
+  builder = "nixpkgs-flake";
+  mkPackage = package: {
+    inherit systems package builder;
+  };
+
+in
+{ config }:
 {
-  perSystem =
-    {
-      pkgs,
-      lib,
-      inputs',
-      ...
-    }:
-    {
-      packages.conduit-next = pkgs.callPackage ./conduit {
-        src = inputs.conduit-src;
-        crane = inputs.crane.mkLib pkgs;
-        fenix = inputs'.fenix.packages;
-      };
-
-      packages.git-commit-last = pkgs.writeShellApplication {
-        name = "git-commit-last";
-        text = ''
-          GITDIR="$(git rev-parse --git-dir)"
-          git commit -eF "$GITDIR/COMMIT_EDITMSG"
-        '';
-      };
-
-      packages.git-fixup = pkgs.writeShellApplication {
-        name = "git-fixup";
-        text = ''
-          git log -n 50 --pretty=format:'%h %s' --no-merges | \
-          ${lib.getExe pkgs.fzf} | \
-          cut -c -7 | \
-          xargs -o git commit --fixup
-        '';
-      };
+  config.packages.conduit-next = {
+    inherit systems builder;
+    package = import ./conduit;
+    settings.args = {
+      src = config.inputs.conduit-src.result;
+      crane = config.inputs.crane.result.mkLib;
+      fenix = config.inputs.fenix.result.packages;
     };
+  };
+
+  config.packages.git-commit-last = mkPackage (
+    { writeShellApplication }:
+    writeShellApplication {
+      name = "git-commit-last";
+      text = ''
+        GITDIR="$(git rev-parse --git-dir)"
+        git commit -eF "$GITDIR/COMMIT_EDITMSG"
+      '';
+    }
+  );
+
+  config.packages.git-fixup = mkPackage (
+    {
+      lib,
+      writeShellApplication,
+      fzf,
+    }:
+    writeShellApplication {
+      name = "git-fixup";
+      text = ''
+        git log -n 50 --pretty=format:'%h %s' --no-merges | \
+        ${lib.getExe fzf} | \
+        cut -c -7 | \
+        xargs -o git commit --fixup
+      '';
+    }
+  );
 }