Update: add option to append more jvm options

minecraft/minecraft.nix

@@ -214,6 +214,14 @@ in {
             '';
           };
 
+          customJVMOpts = mkOpt' (
+            with types;
+              coercedTo
+              (listOf str)
+              (lib.concatStringsSep " ")
+              (separatedString " ")
+          ) "" "Custom JVM options for this server.";
+
           operators = mkOption {
             type = types.attrsOf (
               types.coercedTo minecraftUUID (v: {uuid = v;}) (
@@ -313,8 +321,6 @@ in {
           #   };
           # };
 
-
-
           schedules = mkOption {
             type = types.attrsOf (types.submodule ({name, ...}: {
               options = {
@@ -367,7 +373,15 @@ in {
         lib.mapAttrs (serverName: serverCfg: {
           enable = serverCfg.enable;
           package = serverCfg.package;
-          jvmOpts = "-Xmx${serverCfg.memory.max} -Xms${serverCfg.memory.min}";
+
+          jvmOpts = lib.concatStringsSep " " (
+            [
+              "-Xmx${serverCfg.memory.max}"
+              "-Xms${serverCfg.memory.min}"
+            ]
+            ++ lib.optional (serverCfg.customJVMOpts != "") serverCfg.customJVMOpts
+          );
+
           autoStart = serverCfg.autoStart;
 
           symlinks = serverCfg.symlinks;
@@ -485,7 +499,6 @@ in {
       cfg.servers
     );
 
-
     #     systemd.services = lib.mkMerge (
     #       lib.mapAttrsToList (serverName: serverCfg:
     #         lib.mkIf serverCfg.userActivity.enable {
@@ -506,7 +519,6 @@ in {
     #       ) cfg.servers
     #     );
 
-
     # systemd.timers = lib.mkMerge (
     #   lib.mapAttrsToList (serverName: serverCfg:
     #     lib.mkIf serverCfg.userActivity.enable {
@@ -523,8 +535,6 @@ in {
     #   ) cfg.servers
     # );
 
-
-
     # this is building the scripts for the user
     # Those are the prewritten scripts from the ./Script dir
     environment.systemPackages = lib.flatten (