registries.json report missing biome registry

Where is this missing from exactly?

I see an instance of minecraft:biome under "minecraft:worldgen/material_condition" (Line 16581 for me), and another under "minecraft:worldgen/placement_modifier_type" (Line 16631)

There's also a mention of it under "minecraft:chunk_status" with it being listed as "minecraft:biomes" (Line 4378)

I'm sorry, I should have been more specific. I would expect there to be a top-level key named "minecraft:biome" that looks as follows:

{
  "minecraft:biome": {
    "entries": {
      "minecraft:badlands": {
        "protocol_id": <id>
      },
      ...
      "minecraft:plains": {
        "protocol_id": <id>
      },
      ...
    },
    "protocol_id": <id>
  }
}

In essence, it should list the contents of the biome registry - meaning, all biomes registered within the game and their respective protocol IDs - the same way it is done for items ("minecraft:item"), potions ("minecraft:potion"), and all other other registries that are present within the registries.json file.

The presence of "minecraft:biome" as an entry of other registries is not helpful, as the list of biome protocol IDs is nowhere to be found.

Ah! I see what you mean now. Thanks for clarifying

Invalid. Since 1.16.2, the registry is called "minecraft:worldgen/biome", and that one isn't missing.

I don't think that is correct; "minecraft:worldgen/biome" isn't present in my registries.json file, either (even when using the "--all" flag with the command).

Can confirm (1.20.4 & 1.20.5-pre3) that there is no top-level entry for minecraft:biome and/or minecraft:worldgen/biome in generated/reports/registries.json. I'm not enough of an expert with these generated reports to know whether this is expected; but to my knowledge there is a biome registry so it seems suspicious that it's not there.

The registry is still called "minecraft:worldgen/biome", but since a few versions it is not exported from the data generators, but instead it is included in the version jar (just like all other registries that can be inside a data pack). If you extract the jar you can find the biomes in data/minecraft/worldgen/biome.

Since the registries already included in the jar file are all not being generated when running the data generator, I'll close this as Invalid. While adding in-jar registries to the generated files could make sense, that'd not be a bug but a feature request.

Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support (Technical Issues) – 📧 Microsoft Support (Account Issues)
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki