Wither skeletons don't spawn inside of wither roses

This got caused by the fix of MC-173115.

Might? this was a semi-joke after we saw that fix

so now with 20w19a no mob can spawn in wither roses?

I'm not sure this is a bug. If this were to be used, it would simply make Wither Skeleton farms extremely overpowered and cause wither skeleton skulls to be coming out like they are nothing. 

@Evington Frank, this would have no effect on wither skeleton farms as they do not take damage from wither roses.

@PancakeIdentity it would cause an influx of either skeletons spawning because there wouldn't be any other mobs. The mob cap would consist purely of wither skeletons rather than a mix of mobs, so there would be more wither skeletons spawning

@Evington Frank The problem is this change is inconsistent with other spawning mechanics. (Like zombie pigmen & magma cubes spawning on magma blocks because they're fire resistant.) Imo wither skeleton farms aren't a good enough reason to warrant this inconsistent behavior.

changin this would be hard, cos of they way they fixed MC-173115.

Cos they made the .json file, meaning that you would go back and make a special exception for wither skellies in the code, similar I guess to how they do for magma block, tho this is spawning in the block, which may be a whole other part of the code. Idk, I haven't read this part of the code in detail. My bad, I guess

changin this would be hard, cos of they way they fixed MC-173115.

That change could be re-worked. Perhaps, rather than having a list of blocks mobs can't spawn in, you could have a whitelist and/or blacklist of mobs that can spawn within a given block.

Admittedly not as neat as a single list, but perhaps more flexible.

Another option would be to have the list contain either a blockid string, or an object containing more detailed information, for example:

[
   "minecraft:rails",
    {
        "block": "minecraft:wither_rose",
        "exceptions": [
            "minecraft:wither_skelleton"
        ]
    }
]

This has the advantage of a single simple list for most cases, with optional flexibility when needed. The same system could be also adopted for the existing "cannot spawn on top of" system for magma blocks.

But spawning on top of and spawning inside are rather different things, meaning you would have to do different things for spawning on top of blocks and spawning in blocks .json files.

One thing to consider when discussing power level is the amount of work it take to get to this point to begin with. To have a wither-rose based farm you need to have already spawned the wither. So we’re already super-late game at this point. 

1. Not only having a wither rose farm is quite difficult, but a spawnproof area of 8 chunks on every direction is a high level work, I digged/tnt out a whole 21x21 chunks area, breaking this kind of thinks that only crazy or high level players do is rly annoying and sad. Hope this get fixed, if not I'll be completely out of this version (redstone and wither out, this is not for me).

2. Keep up the good work Mojang and I hope all of the people reading this are okay on this hard times ^^

Yeah wither skeletons farms take a lot of effort, even with this change they would still take tens of hours to construct. 

Plus this bugfix would make sense; wither skeletons aren't hurt by wither roses so why shouldn't they be able to spawn on them?

One thing to consider when discussing power level is the amount of work it take to get to this point to begin with. To have a wither-rose based farm you need to have already spawned the wither. So we’re already super-late game at this point. 

@Joel, that's not true. You can do this even before visiting the end. You just need a bit of soulsand, some obsidian, and zombie spawner or something and then you can get wither roses really easily. And the farm can be built before goind to the end as well

If we go by relatively recent tweets of a couple developers, we can see they're highly interested in mobfarms, how many of the community use them and in which way, and they said they want to balance them, so we have to keep this in mind. (See e.g. fish farms.)

So before we juggle with arguments like "consistency" (those can be easily countered and are often just used to hide the fact one wants an easy and fast/high-drop farm), we should have hard facts, actual numbers, data from few days realtime of farmtesting, to see whether or not having Skeletons spawn as sole mobs would cause a considerable influx (and thus also lots of Wither Skeleton heads) which would not be in a dimension where Mojang would still consider it "balanced" or not "too OP".

If this won't be the case, and it's confirmed from several sources, then that would be at least a valid argument, but not those pro-arguments I've read here thus far.

The first reason they should spawn inside of wither roses is because they dont get dmg, just like other mobs spawning inside of other type of flower (like poppys), so why they shouldnt?
And second reason is like pigmans, they can spawn on top of magma blocks, because they are fire resistant, just like the wither skeleton is immune to the wither effect, so he should be able to spawn inside of it.
 

Please do not use this comments section as a discussion forum. Please use our subreddit /r/Mojira or our Discord server instead.

Then what is the purpose of this comment's section, if not for discussion about this bug and the implications of fixing it or leaving it in the game?

As @Meri Diana said, I think this would make for super easy wither skeleton farms, and the obtaining of insanely high wither skulls. But the thing is that part of the reason why people build wither skeleton farms is also to get blaze rods, gold AND wither skeletons all at once, so most farms would likely remain unchanged. Not to mention that there are a number of wither skeleton farms for which putting roses on the ground is not viable, as the spawning platform is made of blocks on which wither roses cannot be placed, eg: packed ice or glazed terracotta.

So I think we should definitely still have some more discussion as to the implications of fixing this. I could also just run a simulation of a wither skeleton farm in which all other mobs are disabled from spawning via a command, and then see if it is truly the case that it would be overpowered, or whether the rates are reasonable, giving you're missing out on gold, arrows (if you like them) and blaze rods in exchange for potentially more coal, bones and wither skulls

The purpose of the comments section on bug reports is to add important crucial information to the ticket if it isn't already included; such as if someone does a code analysis (not applicable in this case), or if you find the issue is present in a new version. Or you can request a ticket to be linked to another ticket if it's related.

We need to monitor incoming comments in order to react to them, and these discussions drown out the actually important things. Hence we ask to move them over somewhere else.

To put it more clearly: The comments section is for comments regarding the ticket / bug report. It is not for discussing the bug itself (i.e. discussing whether it should be fixed or not, that's completely irrelevant here).

@unknown I'm sorry, usually I comply with that and write it myself, but this here is not a mere discussion right now, but something more fundamental and adds to this bugpost, which is the prerequisite for adding comments.

@unknown 1. As it'd make farming Wither skulls in this case potentially too easy and thus drop too large amounts of skulls. Hence I'd love to have the actual numbers. Would be sad if this gets fixed, but the resulting skull farms would be too OP and Mojang would revert it again, creating another outcry.

As for other types of flowers: Mojang simply could make all flowers spawn-proof to create a general "consistency" case for flowers.

2. The magmablock argument is imo invalid, as it's a completely different block and situation; the argument "mob X may spawn on block Z because it doesn't take damage from it" - if Mojang came up with it themself back then - was a nice candy they gave the tech community 4 years ago.

We've got a different situation now, Mojang is balancing, so you can't always use arguments from another block, situation and time, for anything that facilitates your farming.

@Meri Diana I understand your point about consistency not being a good enough reason, but I disagree that it is an invalid argument. Currently in Minecraft we know that this is true:

1. Magma blocks are a valid block for mob spawning (well, they were before they were changed)

2. Blazes, zombie pigmen, etc. are immune to the damage the magma block deals

3. Therefore, they are allowed to spawn on magma blocks

Using the same logic that's already in the game, it follows that:

1. The wither rose is a flower, which is a valid block for mob spawning

2. The wither skeleton is immune to the wither effect

3. Therefore, the wither skeleton is allowed to spawn on the wither rose

It would follow all current "rules" in the game for wither skeletons to be able to spawn on wither roses. I understand if Mojang wants to break this consistency for the purpose of nerfing mob farms, but I still feel that this is a valid argument.

Also I ran a short test just now, using Ray's wither rose wither skeleton farm and a bunch of repeating command blocks that instantly kill every entity that isn't a wither skeleton. (To simulate an only wither skeleton enviroment) I ran the test on vanilla 1.15.2 in a singleplayer world, with my render distance set to 10 chunks. The farm ended up generating about 63 skulls/hr, which is incredibly close to the 60 skulls/hr the farm generates without the unwanted mobs being instantly killed. (So close that I would say the rates are exactly the same.)

Something important to note is that the unwanted mobs do briefly add to the mob cap during the split second of their existence, so this is only an approximation of what the new rates would be; in reality they might be higher but I'm not sure by how much. It's also possible that Ray's farm never fully takes up the mob cap, which I think would explain why the rates are exactly the same even when I'm instantly killing all mobs that aren't wither skeletons. If this were true, there would be no increase in the skulls/hr with this bugfix right?

Unfortunately I don't know how to entirely disable the spawning of certain mobs so this certainly isn't a conclusive test, I just figured I should put the numbers here because it's a very interesting result.

Please go here to continue the discussion: https://www.reddit.com/r/Mojira/comments/gfrzn6/mc182743_wither_skeletons_dont_spawn_inside_of/

Any further comments are going to be removed unless they contribute to the ticket itself.

Affects 20w20a and 20w20b

I am actively playing in 20w21a and despite this bug fix I'm still getting no Wither Skeleton spawns on/in wither roses. Two of our players were at our wither skeleton farm with nearly the most optimal spawning conditions and we are well over 24 blocks away. No spawns, hoping this helps!<3

Two separate users report this issue still occurs on 20w21a - reopening, please see recent duplicates for more info.

The issue may be down the fortress not spawning fortress mobs rather than wither skeletons not spawning in wither roses. I've read reports of peoples guardian farms not working which is kind of a similar issue.

I've heard that mobs no longer spawn in structures in general, so this might not necessarily be directly related to wither roses and wither skeletons. See also MC-184311, MC-184685, and MC-184740.

I just did some testing, and even in a newly generated nether fortress, wither skeletons don't seem to spawn on wither roses, though it was a limited test so it is not conclusive - but still may be related to the change of structure names.

I doubt this issue is caused by the game not recognizing the fortress even though there is a fortress there. I've removed all withered roses and replaced the dirt with nether brick. No mobs are spawning on the bricks, there should be mobs spawning on the bricks.

The farm I use has a quad intersection with a perimeter slabbed. The game just doesn't spawn in the monsters.

Testing at a pre-made and perimeter clear wither skeleton farm, and a newly discovered fortress, i can verify it is still the spawning in rose issue, as skeletons and blazes are spawning in a new fortress without issue.

Has anyone actually reproduced this bug in a Fortress generated in 20w21a? I suspect this bug is actually fixed but testers are experiencing MC-184740 because they used worlds generated before 20w21a.

I have indeed tried to reproduce is in a new fortress, and couldn't get any to spawn - however, it was a very limited test so I wouldn't count on it being fully accurate.

I've just done a very short test, and this DOES appear to be fixed.  Here's just a very basic test.  I believe that the other players having issues with this may be experiencing other bugs, as currently nether fortresses have many issues right now.

Thank you very much for taking the time to test in more detail 🙂

For everyone experiencing this in 20w21a, it's actually MC-184740.