synit: copy eudev rules to /var in stage 2

nixos/modules/system/boot/stage-2-init.sh

@@ -110,6 +110,8 @@ $systemConfig/activate
 # Record the boot configuration.
 ln -sfn "$systemConfig" /run/booted-system
 
+# copy eudev rules over to /var
+cp -ru @eudev@/var/lib/udev /var/lib/
 
 # Run any user-specified commands.
 @shell@ @postBootCommands@

nixos/modules/system/boot/stage-2.nix

@@ -15,6 +15,7 @@
         pkgs.utillinux
         pkgs.synit-pid1
       ];
+      inherit (pkgs) eudev;
       postBootCommands = pkgs.writeText "local-cmds" ''
         ${config.boot.postBootCommands}
         ${config.powerManagement.powerUpCommands}

nixos/modules/system/boot/synit.nix

@@ -102,6 +102,7 @@ with lib;
         initialScanScript = pkgs.writeScript "eudev-initial-scan.sh" ''
           #!${pkgs.runtimeShell}
           set -e
+          export PATH=${lib.makeBinPath [ pkgs.eudev ]}
           echo "" > /proc/sys/kernel/hotplug
           udevadm trigger --type=subsystems --action=add
           udevadm trigger --type=devices --action=add