Fight mod internal usage

https://github.com/TerraformersMC/Terraform/blob/0d569ebf8e6c78c79ccdb8b8f28c081089764aef/terraform-biome-remapper-api-v1/src/main/java/com/terraformersmc/terraform/biomeremapper/impl/mixin/MixinLevelStorageSession.java#L41

fabric-item-group-api-v1/src/client/java/net/fabricmc/fabric/mixin/itemgroup/client/CreativeInventoryScreenMixin.java

@@ -27,6 +27,7 @@
 import org.spongepowered.asm.mixin.Final;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
 
 import java.util.List;
 import java.util.Objects;
@@ -36,11 +37,14 @@ public abstract class CreativeInventoryScreenMixin<T extends AbstractContainerMe
 	@Shadow
 	@Final
 	private List<CreativeTabsScreenPage> pages;
-	@Shadow
-	private CreativeTabsScreenPage currentPage;
+	@Shadow(aliases = "currentPage")
+	private CreativeTabsScreenPage currentSelectedPage;
 	@Shadow
 	private static CreativeModeTab selectedTab;
 
+	@Unique // Kept for mod internal usage
+	private static int currentPage;
+
 	@Shadow
 	abstract void setCurrentPage(CreativeTabsScreenPage currentPage);
 
@@ -63,24 +67,24 @@ public boolean switchToPage(int page) {
 	@Override
 	public boolean switchToNextPage() {
 		if (hasAdditionalPages()) {
-			this.setCurrentPage(this.pages.get(this.pages.indexOf(this.currentPage) + 1));
+			this.setCurrentPage(this.pages.get(this.pages.indexOf(this.currentSelectedPage) + 1));
 			return true;
 		}
 		return false;
 	}
 
 	@Override
 	public boolean switchToPreviousPage() {
-		if (this.pages.indexOf(this.currentPage) > 0) {
-			this.setCurrentPage(this.pages.get(this.pages.indexOf(this.currentPage) - 1));
+		if (this.pages.indexOf(this.currentSelectedPage) > 0) {
+			this.setCurrentPage(this.pages.get(this.pages.indexOf(this.currentSelectedPage) - 1));
 			return true;
 		}
 		return false;
 	}
 
 	@Override
 	public int getCurrentPage() {
-		return this.pages.indexOf(this.currentPage);
+		return this.pages.indexOf(this.currentSelectedPage);
 	}
 
 	@Override
@@ -102,7 +106,7 @@ public int getPage(CreativeModeTab itemGroup) {
 
 	@Override
 	public boolean hasAdditionalPages() {
-		return this.pages.indexOf(this.currentPage) < this.pages.size() - 1;
+		return this.pages.indexOf(this.currentSelectedPage) < this.pages.size() - 1;
 	}
 
 	@Override
@@ -118,7 +122,7 @@ public boolean setSelectedItemGroup(CreativeModeTab itemGroup) {
 			return false;
 		}
 
-		if (pages.indexOf(currentPage) != getPage(itemGroup)) {
+		if (pages.indexOf(currentSelectedPage) != getPage(itemGroup)) {
 			if (!switchToPage(getPage(itemGroup))) {
 				return false;
 			}
@@ -127,4 +131,14 @@ public boolean setSelectedItemGroup(CreativeModeTab itemGroup) {
 		selectTab(itemGroup);
 		return true;
 	}
+
+	@Unique
+	@Deprecated // Kept for mod internals
+	private boolean isGroupVisible(CreativeModeTab tab) {
+		return tab.shouldDisplay() && getCurrentPage() == getPage(tab);
+	}
+
+	@Unique
+	@Deprecated // Kept for mod internals
+	private void updateSelection() {}
 }

fabric-registry-sync-v0/src/main/java/net/fabricmc/fabric/impl/registry/sync/RegistryMapSerializer.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.fabricmc.fabric.impl.registry.sync;
+
+import it.unimi.dsi.fastutil.objects.Object2IntMap;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.resources.ResourceLocation;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@Deprecated // Only for fighting internal usage by mods
+public class RegistryMapSerializer {
+	public static final int VERSION = 1;
+
+	public static Map<ResourceLocation, Object2IntMap<ResourceLocation>> fromNbt(CompoundTag nbt) {
+		return new HashMap<>();
+	}
+
+	public static CompoundTag toNbt(Map<ResourceLocation, Object2IntMap<ResourceLocation>> map) {
+		return new CompoundTag();
+	}
+}

ffapi.gradle.properties

@@ -1,7 +1,7 @@
 loom.platform=neoforge
 fabric.loom.dontRemap=true
 
-implementationVersion=2.0.2
+implementationVersion=2.0.3
 
 versionMc=1.21
 versionForge=21.0.57-beta