suppress launchwrapper classloading failure

src/main/java/me/modmuss50/optifabric/mixin/ReflectorClassMixin.java

@@ -0,0 +1,27 @@
+package me.modmuss50.optifabric.mixin;
+
+import org.spongepowered.asm.mixin.*;
+import org.spongepowered.asm.mixin.injection.*;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+// suppresses some warnings in the log
+@Pseudo
+@Mixin(targets = "ReflectorClass")
+public class ReflectorClassMixin {
+    @Shadow
+    private String targetClassName;
+
+    @Shadow
+    private boolean checked;
+
+    @SuppressWarnings("UnresolvedMixinReference")
+    @Inject(method = "getTargetClass", at = @At("HEAD"), remap = false)
+    private void getTargetClass(CallbackInfoReturnable<Class<?>> infoReturnable) {
+        if (!checked) { // only check the target if it hasn't been done yet
+            String name = targetClassName.replaceAll("/", ".");
+            if (name.startsWith("net.minecraft.launchwrapper") || name.startsWith("net.minecraftforge") || "optifine.OptiFineClassTransformer".equals(name)) {
+                checked = true;
+            }
+        }
+    }
+}

src/main/java/me/modmuss50/optifabric/mod/OptifabricSetup.java

@@ -5,6 +5,7 @@
 import me.modmuss50.optifabric.patcher.ClassCache;
 import net.fabricmc.loader.api.*;
 import net.fabricmc.loader.api.metadata.ModMetadata;
+import org.spongepowered.asm.mixin.Mixins;
 
 import java.io.File;
 import java.util.*;
@@ -36,6 +37,7 @@ public void run() {
             }
             throw new RuntimeException("Failed to setup optifine", e);
         }
+        Mixins.addConfiguration("optifabric.optifine.mixins.json");
     }
 
     private boolean validateMods() {

src/main/resources/optifabric.optifine.mixins.json

@@ -0,0 +1,8 @@
+{
+  "required": true,
+  "package": "me.modmuss50.optifabric.mixin",
+  "compatibilityLevel": "JAVA_8",
+  "mixins": [
+    "ReflectorClassMixin"
+  ]
+}