Please edit your post to either remove the coordinates or enclose them in a spoiler (the ! on your toolbar).
I always do large biomes, it's my personal default.
That said, Amidst shows the two woodland mansions, but when I went to the first one, there wasn't one.
I'm trekking my way to the next one now. I also always disable cheats, so no teleporting for me.
That all said.. I have to say, I'm liking the world more and more. I've found 2 books of mending and a book of Effeciency 4 along the way, along with 3 diamonds. As soon as I find a homebase.... I'm fairly set for a good start.
I've seen this once before out of thousands of spawners (if not mineshafts, which I've explored around 600 of in my first world alone), as well as several instances of two spawners separated by one block.
As noted by Hexalobular, the direction you explore in can affect the placement of spawners and even the overall generation of structures*; in particular, because of the way the game places large structures (chunk by chunk) and how it places spawners (one within a "corridor" which is 1-4 sections (supports) long, which means they can be up to 20 blocks long) it can place two down when the chunks containing the corridor have been generated in separate play sessions and structure data was not saved (prior to 1.6.4 and apparently since 1.13; I say the latter because there are various generation bugs of the sort that occur without structure saving, such as buildings split vertically across chunk boundaries (villages and most other surface structures need to save the elevation of the area prior to being placed to avoid contamination by part of a structure which was placed before), which I've also reproduced in 1.6.4 by deleting the structure file when a village was partly generated at the edge of generated chunks. Supposedly, 1.13 moved structure saving to regions but it seems to be bugged. Note that I removed structure saving from mineshafts in my own mods to avoid a potential performance issue, even then, I've only seen one double spawner and the chunks it was in were generated in 1.5.1-1.5.2).
Here is the code that places spawners; "sectionCount" is the number of sections (supports) in the corridor, ranging from 1-4 (5-20 blocks) while "spawnerPlaced" is used to tell whether it has placed a spawner (this value is normally saved in structure data), and "par3StructureBoundingBox.isVecInside" checks if the coordinates are within the bounding box of the area being populated (only blocks that are within this area are placed). If the state of "spawnerPlaced" is not saved between sessions as many as 3 spawners (not the intended one) can be placed within a corridor since they can intersect up to 3 populated areas along their length. Note that regardless of structure saving only one spawner should be placed within a session since the game keeps everything loaded in memory until you quit the world:
*Example; the first one is what you get when you approach from from the north while the second is what you get when you come from the south. The glitched/missing mineshaft in the first is due to water springs generating in the walls created by the mineshaft, which generated partly because it crosses a chunk boundary (or rather, offset by 8 boundary) and the rest of the mineshaft section did not generate because they do not generate if part of them intersect water or lava. At least in this case both generations were 100% reproducible; you can also see that ores generated differently around the mineshaft, since a single RNG is used during chunk population and any changes will cascade down the line, affecting all features placed afterwards (structures are placed first while springs are placed last. The actual layout of structures uses a different RNG and does not change, but things like cobwebs are placed randomly during chunk population, so the presence/absence of part of a mineshaft will affect the RNG):
From the north:
From the south:
Also, Optifine's "Fast Math" setting causes slight changes to world generation because it reduces the size/accuracy of a sine lookup table, which causes minor differences in terrain, even if just one block here and there, but that is enough to cause some decorations to be placed differently (e.g. dungeons require a specific number of air blocks in their walls, plants and many other features require specific blocks to generate on; as mentioned above, any differences in one feature will cascade down the line, even affecting what is placed in adjacent populated regions due to overlap).
In addition, if you've ever deleted chunks and then found structures missing chests/spawners/mobs this is because the game records whether they were placed and this data is saved separately from chunks/regions (prior to 1.13, which as mentioned doesn't seem to work anyway). Repopulating chunks can cause duplicated features, including chests/spawners/mobs, though they will usually be overwritten or not duplicated due to having already been placed (one exception is minecart chests, which will be duplicated regardless of structure saving since it doesn't record whether they were placed).
Yo! Mastercaver --- is there any way for me to get my ORIGINAL MCforum account back? I had close to 300-400 posts to it, a really nice avatar and such.... but when I switched over to the new Twitch deal (I waited for over a year to do so) it started me over at zero and gave me stupid numbers after my name.
My old posts are out there, i've gone back to a few... but is there anyway to merge these two accounts back into one?
IT's after midnight on my side of the world... catch up on this tomorrow. Thanks in advance for any advice.... and I still love the double spawner. That's just too cool.
I noticed that the chunk border goes between the spawners so if they had been shifted they should have "belonged" to the same chunk and I would have expected them to be placed at the same time?
Spawners (and mineshafts) are placed within "offset chunks" like everything else; only the base terrain and caves are generated within whole chunks (and if they haven't fixed this yet, emerald ore and hidden lava blocks in the Nether, which do not have an offset of +8 and the latter causes a limited degree of runaway world generation since they check adjacent blocks, which can be in unloaded chunks, which are forced to load/generate when accessed).