1.18.1 Mixin ClassCastException on accessor

[matezz]

Hi, I'm trying to get the particle providers of my newly registered particles. Because the method in ParticleEngine is private, I used mixin accessor to get the field of `net.minecraft.client.particle.ParticleEngine#providers`:

@Mixin(ParticleEngine.class)
public interface ParticleEngineMixin {
    @Accessor
    Map<ResourceLocation, ParticleProvider<?>> getProviders();
}

and to register a new particle and get the provider I use:

Minecraft.getInstance().particleEngine.register(particleType, PARTICLE_FACTORIES.get(registryName));
if (((ParticleEngineMixin) Minecraft.getInstance().particleEngine).getProviders().get(registryName) instanceof WNParticleProvider<?> provider) {
    PARTICLE_PROVIDERS.put(registryName, provider);
}

And now, when I launch it in the IDE, everything works fine, particles are registered and I have providers. But when I try to launch the mod in Minecraft after build, it throws me an exception:

net.minecraftforge.fml.ModLoadingException: xxx Mod (xxx) encountered an error during the common_setup event phase
§7java.lang.ClassCastException: class net.minecraft.client.particle.ParticleEngine cannot be cast to class net.matez.xxx.mixin.ParticleEngineMixin (net.minecraft.client.particle.ParticleEngine is in module minecraft@1.18.1 of loader 'TRANSFORMER' @6c5ddccd; net.matez.xxx.mixin.ParticleEngineMixin is in module xxx@3.1_indev_4 of loader 'TRANSFORMER' @6c5ddccd)
	at net.minecraftforge.fml.javafmlmod.FMLModContainer.acceptEvent(FMLModContainer.java:124) ~[javafmllanguage-1.18.1-39.0.66.jar%2356!/:?] {}
	at net.minecraftforge.fml.ModLoader.lambda$postEvent$31(ModLoader.java:298) ~[fmlcore-1.18.1-39.0.66.jar%2355!/:?] {}
	at java.util.HashMap.forEach(HashMap.java:1421) ~[?:?] {}
	at net.minecraftforge.fml.ModList.forEachModContainer(ModList.java:232) ~[fmlcore-1.18.1-39.0.66.jar%2355!/:?] {}
	at net.minecraftforge.fml.ModLoader.postEvent(ModLoader.java:298) ~[fmlcore-1.18.1-39.0.66.jar%2355!/:?] {}
	at net.minecraft.client.Minecraft.<init>(Minecraft.java:507) ~[client-1.18.1-20211210.034407-srg.jar%2354!/:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
	at net.minecraft.client.main.Main.main(Main.java:169) ~[client-1.18.1-20211210.034407-srg.jar%2354!/:?] {re:classloading,pl:runtimedistcleaner:A}
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?] {}
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[?:?] {}
	at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?] {}
	at java.lang.reflect.Method.invoke(Method.java:568) ~[?:?] {}
	at net.minecraftforge.fml.loading.targets.CommonClientLaunchHandler.lambda$launchService$0(CommonClientLaunchHandler.java:45) ~[fmlloader-1.18.1-39.0.66.jar%2323!/:?] {}
	at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37) [modlauncher-9.1.0.jar%235!/:?] {}
	at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:53) [modlauncher-9.1.0.jar%235!/:?] {}
	at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:71) [modlauncher-9.1.0.jar%235!/:?] {}
	at cpw.mods.modlauncher.Launcher.run(Launcher.java:106) [modlauncher-9.1.0.jar%235!/:?] {}
	at cpw.mods.modlauncher.Launcher.main(Launcher.java:77) [modlauncher-9.1.0.jar%235!/:?] {}
	at cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:26) [modlauncher-9.1.0.jar%235!/:?] {}
	at cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:23) [modlauncher-9.1.0.jar%235!/:?] {}
	at cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:149) [bootstraplauncher-1.0.0.jar:?] {}
Caused by: java.lang.ClassCastException: class net.minecraft.client.particle.ParticleEngine cannot be cast to class net.matez.xxx.mixin.ParticleEngineMixin (net.minecraft.client.particle.ParticleEngine is in module minecraft@1.18.1 of loader 'TRANSFORMER' @6c5ddccd; net.matez.xxx.mixin.ParticleEngineMixin is in module xxx@3.1_indev_4 of loader 'TRANSFORMER' @6c5ddccd)
	at net.matez.xxx.common.registry.particles.WNParticles.lambda$registerFactories$0(WNParticles.java:56) ~[xxx-3.1_indev_4.jar%2353!/:3.1_indev_4] {re:classloading}
	at java.util.LinkedHashMap.forEach(LinkedHashMap.java:721) ~[?:?] {}
	at net.matez.xxx.common.registry.particles.WNParticles.registerFactories(WNParticles.java:53) ~[xxx-3.1_indev_4.jar%2353!/:3.1_indev_4] {re:classloading}
	at net.matez.xxx.client.registry.setup.WNClientRegistry.registerParticleFactories(WNClientRegistry.java:29) ~[xxx-3.1_indev_4.jar%2353!/:3.1_indev_4] {re:classloading,pl:runtimedistcleaner:A}
	at net.minecraftforge.eventbus.EventBus.doCastFilter(EventBus.java:247) ~[eventbus-5.0.3.jar%232!/:?] {}
	at net.minecraftforge.eventbus.EventBus.lambda$addListener$11(EventBus.java:239) ~[eventbus-5.0.3.jar%232!/:?] {}
	at net.minecraftforge.eventbus.EventBus.post(EventBus.java:302) ~[eventbus-5.0.3.jar%232!/:?] {}
	at net.minecraftforge.eventbus.EventBus.post(EventBus.java:283) ~[eventbus-5.0.3.jar%232!/:?] {}
	at net.minecraftforge.fml.javafmlmod.FMLModContainer.acceptEvent(FMLModContainer.java:120) ~[javafmllanguage-1.18.1-39.0.66.jar%2356!/:?] {}
	... 19 more

which is actually weird, as all the tutorials say that I can cast my target class with a mixin to access @Accessor. Maybe I'm doing something wrong?
 

Mixin config: refmap enabled, mixin added to "client" in config, mixin version `org.spongepowered:mixingradle:0.7-SNAPSHOT`, forge `1.18.1-39.0.63`, annotationProcessor `org.spongepowered:mixin:0.8.5:processor`
I couldn't use AccessTransformers, they didn't work.

[Luis_ST]

Mixin is not supported on this Forum,
but you can get help on the Forge Discord in the non-api-modding channel

[diesieben07]

If they are your particles, why on earth do you not have their provider already? I mean, you are the one registering it...

[matezz]

Minecraft supplies provider.create(<spriteset>) on registry, I can't create my own spriteset.

I'm just asking why I can't cast this mixin to the target class - only after build. It could be a different class, not the ParticleEngine one. If one doesn't work, the rest wouldn't work too.

[diesieben07]

Like was already said, Mixin and coremodding is not supported here. Use reflection if you think you must do this (you don't).