PaperMC/paper-server/patches/sources/net/minecraft/gametest/framework/GameTestServer.java.patch

--- a/net/minecraft/gametest/framework/GameTestServer.java
+++ b/net/minecraft/gametest/framework/GameTestServer.java
@@ -304,6 +_,13 @@
         return false;
     }
 
+    // Paper start
+    @Override
+    public org.bukkit.command.CommandSender getBukkitSender(final net.minecraft.commands.CommandSourceStack wrapper) {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+    // Paper end
+
     @Override
     public boolean isSingleplayerOwner(GameProfile profile) {
         return false;