Mixin only works in dev 1.21.4-54.1.0

[Suamere]

I am working in the latest MDK.  Minecraft 1.21.4, Forge 54.1.0.

I am trying to create a mixin.  The implementation doesn't matter.  Assume it is doing nothing more than logging to the console:

@Mixin(LevelRenderer.class)
public abstract class LevelRendererMixin {
    private static final Logger LOGGER = LogManager.getLogger("LevelRendererMixin");

    @Inject(method = "renderLevel", at = @At("TAIL"))
    private void onRenderLevel(
            com.mojang.blaze3d.resource.GraphicsResourceAllocator allocator,
            net.minecraft.client.DeltaTracker deltaTracker,
            boolean someFlag,
            Camera camera,
            GameRenderer gameRenderer,
            Matrix4f matrix1,
            Matrix4f matrix2,
            CallbackInfo ci
    ) {

Assuming my whole implementation is just to write something to console, it works perfectly fine in when I debug (runClient) in IntelliJ.  Whenever the Minecraft `renderLevel` runs every frame, my logging is overlaid at "TAIL".

Yes, this spams the sht out of the console.

But when I `build` and use the jar as a mod, it does not.  The mixin annotation processor shows to be loading, and my other parts of my mod work, but the nothing gets logged by my mixin.

I am apparently generating a proper `refmap` and it's in the jar root.  Other files are also in the jar appropriately, including mods.toml.  And all the naming and reference paths are correct.

I had to add this to my build.gradle to get my refmap into the jar ([name] obviously replaced):

tasks.register("copyRefmap", Copy) {
    dependsOn tasks.named("compileJava")
    from("${project.buildDir}/tmp/compileJava") {
        include "mixins.[name].refmap.json"
    }
    into("${project.buildDir}/resources/main")
}

tasks.named("processResources", ProcessResources).configure {
    dependsOn(tasks.named("copyRefmap"))
}

tasks.named("jar", Jar).configure {
    // Include the generated refmap from build/resources/main into the jar.
    from("${project.buildDir}/resources/main") {
        include "mixins.[name].refmap.json"
    }
}

 

Just for fun, here is my refmap in case something looks wrong to anybody:
 

{
  "mappings": {
    "com/[name]/mixin/LevelRendererMixin": {
      "renderLevel": "Lnet/minecraft/client/renderer/LevelRenderer;m_109599_(Lcom/mojang/blaze3d/resource/GraphicsResourceAllocator;Lnet/minecraft/client/DeltaTracker;ZLnet/minecraft/client/Camera;Lnet/minecraft/client/renderer/GameRenderer;Lorg/joml/Matrix4f;Lorg/joml/Matrix4f;)V"
    }
  },
  "data": {
    "searge": {
      "com/[name]/mixin/LevelRendererMixin": {
        "renderLevel": "Lnet/minecraft/client/renderer/LevelRenderer;m_109599_(Lcom/mojang/blaze3d/resource/GraphicsResourceAllocator;Lnet/minecraft/client/DeltaTracker;ZLnet/minecraft/client/Camera;Lnet/minecraft/client/renderer/GameRenderer;Lorg/joml/Matrix4f;Lorg/joml/Matrix4f;)V"
      }
    }
  }
}

TLDR;
My mixin works in dev, but not when built and run in an official Forge/Minecraft environment.  Like it's not overlaying/replacing the minecraft function.

What are some typical other things to check when a mixin works in dev, but not after build?

Edited February 16 by Suamere
actual question added