Datagen provider crashing in a NeoForge context

[no-name-provided]

Describe the bug
When attempting to use your entity datagen provider in a Java-only, 1.21.1 NeoForge context, my run consistently crashed with the following error:

Caused by: java.lang.NullPointerException: Cannot invoke "com.mojang.serialization.Codec.optionalFieldOf(String, Object)" because "dev.lambdaurora.lambdynlights.api.entity.luminance.EntityLuminance.LIST_CODEC" is null

This happens even when the body of the generate method is empty. When manually created, the necessary JSON appears to work correctly.

To Reproduce
Steps to reproduce the behavior:

1. Intercept the GatherDataEvent
2. Attempt to add the provider

Expected behavior
A no-op, when #generate is empty, and this JSON when it isn't:

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: [e.g. Linux]
• Minecraft [e.g. 1.16.4]
• Fabric Loader version [e.g. 0.10.6+build.214]
• Mods [e.g. fabric-api v0.25.1+build.416-1.16, lambdynamiclights v1.3.2, modmenu v1.14.6+build.31]
• Version [e.g. 1.3.2]
• Branch [e.g. mc1.16]

Additional context

Compiling against your api, version 4.8.7+1.21.1 using NeoForge version 21.1.202. JSON appears to work when manually created.

[LambdAurora]

Your reproduction code is private.

I can look into reproducing myself, but I have to admit we're very unfamiliar with NeoForge's datagen code. We know someone has used LDL's datagen on NeoForge though, so it's definitely possible, and this perplexes us.
I have to warn though, we may not be able to look into this for a while as this is a busy time of the year.

[no-name-provided]

My apologies - I'd thought it was public. It should now be available.

However, there's not much of relevance in there. I did very little, and it crashes when the provider's constructor (not its generate method) is evaluated.

Again, the entity luminance provider itself appears to work as intended, at least in single player dev.

[LambdAurora]

ok, will take a look once we have enough free time then o7