try to reduce closure

modules/systemd/default.nix

@@ -103,7 +103,6 @@ in
             Before = [ "default.target" ];
           };
           script = ''
-            #!/bin/ash
             # . /etc/profile
             exec /bin/ash < /dev/ttyS0 > /dev/ttyS0 2> /dev/ttyS0
           '';

overlay.nix

@@ -335,8 +335,27 @@ extraPkgs // {
       };
     }) { };
 
+  writeShellScriptBin = name: text:
+    final.writeTextFile {
+      inherit name;
+      executable = true;
+      destination = "/bin/${name}";
+      text = ''
+        #!${final.busybox}/bin/ash
+        ${text}
+      '';
+      checkPhase = ''
+        ${final.stdenv.shellDryRun} "$target"
+      '';
+      meta.mainProgram = name;
+    };
+
   systemd =
     let base = prev.systemd.override {
+      kbd = "";
+      bash = null;
+      bashInteractive = "";
+
       withAcl = false;
       withAnalyze = false;
       withApparmor = false;
@@ -389,6 +408,17 @@ extraPkgs // {
       #  "--optimization=s"
         "--default-library=static"
         "--buildtype=minsize"
+        # (final.lib.mesonBool "static-libsystemd" true)
+        # (final.lib.mesonBool "standalone-binaries" true)
+
+      #  (final.lib.mesonBool "link-udev-shared" false)
+      #  (final.lib.mesonBool "link-executor-shared" false)
+      #  (final.lib.mesonBool "link-systemctl-shared" false)
+      #  (final.lib.mesonBool "link-networkd-shared" false)
+      #  (final.lib.mesonBool "link-timesyncd-shared" false)
+      #  (final.lib.mesonBool "link-journalctl-shared" false)
+      #  (final.lib.mesonBool "link-boot-shared" false)
+      #  (final.lib.mesonBool "link-portabled-shared" false)
       ];
       postInstall = o.postInstall + ''
         rm -rf $out/share
@@ -438,6 +468,9 @@ extraPkgs // {
         rm $out/bin/systemd-sysext
         rm $out/bin/systemd-tty-ask-password-agent
         rm $out/bin/systemd-vpick
+
+        # rm $out/lib/libsystemd.a
+        # rm $out/lib/systemd/libsystemd-shared-256.so
       '';
     });