Report OpenJ9 as unsupported

build.gradle

@@ -13,7 +13,7 @@ apply plugin: 'net.minecraftforge.gradle'
 apply plugin: 'eclipse'
 apply plugin: 'maven-publish'
 
-version = '1.0.10'
+version = '1.0.11'
 group = 'link.infra.jumploader' // http://maven.apache.org/guides/mini/guide-naming-conventions.html
 archivesBaseName = 'jumploader'
 

gradle.properties

@@ -1,3 +1,3 @@
 modGroup=link.infra.jumploader
-modVersion=1.0.10
+modVersion=1.0.11
 modBaseName=jumploader

src/main/java/link/infra/jumploader/Jumploader.java

@@ -35,7 +35,7 @@
 import java.util.Set;
 
 public class Jumploader implements ITransformationService {
-	public static final String VERSION = "1.0.10";
+	public static final String VERSION = "1.0.11";
 	public static final String USER_AGENT = "Jumploader/" + VERSION;
 
 	private final Logger LOGGER = LogManager.getLogger();
@@ -67,6 +67,15 @@ private static <T> T reflectField(Object destObj, String name) throws NoSuchFiel
 	public void onLoad(@Nonnull IEnvironment env, @Nonnull Set<String> set) {
 		LOGGER.info("Jumploader " + VERSION + " initialising, discovering environment...");
 
+		// OpenJ9 is currently unsupported - it does not allow bypassing the reflection blacklist to change the system classloader
+		// See FabricLoaderReflectionHack.java
+		if (System.getProperty("java.vm.name", "").toLowerCase().contains("openj9")) {
+			LOGGER.fatal("OpenJ9 is currently unsupported with Jumploader");
+			LOGGER.fatal("Please use Hotspot, or install your desired modloader directly instead of jumploading it!");
+			LOGGER.fatal("See https://fabricmc.net/wiki/install for a Fabric installation guide");
+			System.exit(1);
+		}
+
 		// Get the game arguments
 		ParsedArguments argsParsedTemp;
 		// Very bad reflection, don't try this at home!!

src/main/resources/fabric.mod.json

@@ -1,7 +1,7 @@
 {
   "schemaVersion": 1,
   "id": "jumploader",
-  "version": "1.0.10",
+  "version": "1.0.11",
 
   "name": "Jumploader",
   "description": "Allows the use of Fabric mods in Twitch modpacks, by loading Fabric as if it were a Forge mod.",