Communities only get populated after someone on your instance subscribes to that community.
PieFed help
It's seems right that we should have a local community to help us all with PieFed
Rules
Be kind! We're all learning
Plus I don't think they'll show up in the Community search, unless someone first (once) adds them via Add remote community and makes the instance aware of its existence.
To the OP: basically ActivityPub quirk, no instances proactively import remote contents, first having to have someone request that information, and how the "request" happens, depends on the software
Ah ok, I might understand, thanks for explaining!
So how am I supposed to add this? I'm still new to the Threadiverse.
Been a while since I used Piefed, but at least ~1 year ago, iirc first you import the community as hendrik said, then you go to the other search page and search for the post using its original url, which always is from the OP's instance, not the community's.
However, 1 year in software development is a lot, so there's a chance Piefed's far less analogical now, and thus the paragraph above may be outdated.
So the importing is being done on what end? I cant find an import on my instance.
Ah, forgive me. Thought you were on Piefed. 😣
ahem From your Lemmy instance, go to feddit.org/search, put the post's link in the search bar, hit enter and wait a little. That way, the post and the skeleton of the community get imported, and following the community lets new posts get imported.
Alternatively, if you want to find just the community, not any specific posts, community mentions help too, e.g. here would be !piefed_help@piefed.social ([!piefed_help@piefed.social](/c/piefed_help@piefed.social)), which you click to get redirected to the given community. Mentions you can find "in the wild", through discovery communities, sending DMs of the mentions to others or to alt accounts, or sending the mentions to communities specifically for testing.
Did it on the search on the "normal" interface, as well on Tesseract for ~5 minutes. Unfortunately, search stays with no results...
EDIT: oh and dont excuse yourself, I'm very grateful for your help
Unsure what exactly you mean by "normal interface", but when I am on Lemmy, I do like this (Ani.Social because it's the Lemmy instance I use):

Yes yes, but it doesnt show anything for the mentioned community:

Same thing when I enter the banged version. From that instance tho, I can find other communities.
Tried searching some posts from that community on Ani.Social, logged off, logged in with NSFW off, and logged in with NSFW on. Logged off, nothing was found, while in both cases logged in, nothing was found. So my theories are either you're not logged in, or the instances aren't communicating. If it's the latter, from what I talked with the administrator of my instance, before LemmyNSFW went under, it had been refusing communication on their side due to iirc their firewall, so maybe worth bringing that to either the administration of feddit.org or fedinsfw, so they can investigate.
Ok, but with other communities on the target instance, I can interact (like upvoting, etc.)
Could it be that only some communities are affected? If so, I'd mail my instance admin for investigation.
Also these in the the attached image are the places where you get the posts' original urls, the ones that are the most likely to work in a fediverse search. And they change depending on the user's instance, e.g. your post and comment link to feddit.org, mine links to thebrainbin.org.

Wait a sec, I thought it was if someone on your instance subscribes to A community in another instance. How is the first person supposed to find a specific community without discovery?
Piefed iirc tackles it by implementing bundles of communities by topics.
Also there are some communities specific for discovery, like !communitypromo@lemmy.ca, !newcommunities@lemmy.world, !trendingcommunities@lemmy.cafe and !lemmydirectory@lemmy.dbzer0.com, which may help.
Also Mbin and Friendica, both supporting thread posts, have microblogging functions (e.g. boosts and following users) which help populating each other and indirectly Piefed and Lemmy.
How is the first person supposed to find a specific community without discovery
I think discoverability is one of the biggest issues facing the fediverse in general and the threadiverse specifically. There are third-party sites that try to catalog the wider ecosystem of communities (like lemmyverse - click the dropdown to switch between lemmy/piefed/mbin), but relying on third-party services like that is far from an ideal solution, and it is a barrier of entry to casual, non-techie users.
Others in the thread have already explained this bit of how federation works, so allow me to provide directions for how to bring an unfederated community to your instance.
On Lemmy:
- Click the magnifying glass at the top of the page to open up the search page.
- Search for the full url of the un-federated community that you want to subscribe to:
https://remote-instance.tld/c/cool-community - Lemmy will say that there are no results found...but don't believe it, just wait on this page a little longer
- After lemmy does some searching in the background, it should list the community below, now you can click through and subscribe to it.
On PieFed:
- Along the top navbar, click the Communities dropdown and select
Add remote community. - In that form you can either enter the full url (like in the lemmy directions) or you can use the ! notation:
!cool-community@remote-instance.tld - PieFed will reach out, find that community, and bring it over, letting you subscribe to it
Tried it on the "normal" interface, as well on Tesseract, both ~5 Minutes. It doesnt show up, just no search results... :C
But thanks for the explanation!