While your particular issues is solved, you should be aware that lemmy.ml is one instance of the Tankie Triad, which many other instances have blocked. Unless you like living in tankieland, I would suggest you make an account somewhere else.
Heaven forbid you encounter any opinions you disagree with.
I'm fine with differing opinions, if done in good faith. I'm not fine with people being nasty (personal attacks, name-calling) and mods being extremely biased (e.g. banning people for criticising Russia, China, North-Korea). I don't need such toxicity in my life.
In my experience the only nastiness I face are from people who attack me for being a """tankie"""
Lemmygrad's moderation if quite strict so I can understand why liberals wouldn't be interested, and hexbear doesn't shy away from personal attacks on liberals, but lemmy.ml seems very reasonable to me.
Your specific problem is solved, but just for people reading this thread who may be confused about some concepts:
Your instance of Lemmy or Mastodon, whichever it may be, is just one website that serves as a Reddit or Twitter clone respectively. There isn't a lot of difference between one single instance of Lemmy or Mastodon on the one hand, and Reddit or Twitter on the other. Just like you need to register and log in on Reddit or Twitter if you want to interact there, you need to do the same on any instance of Lemmy or Mastodon you want to interact on.
So what is the concept of federation then? It doesn't mean you can log into one website with the credentials of another website. All that federation means is that the website downloads some of its data (posts, comments, status updates, whatever) from other websites running the same or compatible software, instead of getting all of it from its own users (like Reddit and Twitter do).
Thank you that is useful to have that explanation here. I had no idea it works like that!
I've not seen this type of logging in issue within the Mastodon 'world' because no one's ever 'sent me a link from another instance and then I tried to log on from that link' ๐. I just tried it on an inprivate browser window and of course it's the same as what I found here with Lemmy - as you described. With Mastodon I'm on the .social instance and I can see and interact with posts from any other instance - but after your explanation I realise that's because the content was alwasy served up from within the instance.
[I agree that with ActivityPub we certainly cannot expect to log in with the same handle *between *services (i.e. use your Mastodon handle to log in to Lemmy). Although that would be cool. Persistent IDs across the fediverse would be the dream imho (like Nostr does it).]
There is an open standard for logging into websites with other websites' credentials, it is called OpenID and long predates ActivityPub (and is independent of it).
Ooooooooh I see! right.... yes that works.
I wasn't familiar with the idea of the instance 'fetching' a post. Thank you!
If you see yourself facing this often, you can also use a browser extension to make it easier to see the post you are at in your instance.
For Firefox and derivatives, the simplest one is Lemmy Link, which places a Lemmy icon next to links such as the sibebar's !community link in the instructions for logged out users to find the community in their own instance. It has not been updated in two years, but still works.
Another option is Kbin Link, which does the same thing and has seen recent updates but tends to trigger "this extension is slowing down..." notifications.
A third one I found is Instance Assistant, which instead adds a "Find in my home instance" button to the sidebar. It does have some additional features, but I couldn't get them to work. This one is also available for Chromium-based browsers.
Thank you all for explaining.
The behaviour I was expecting was to click 'login' on the feddit.nl page, and that login page to recognise that I was logging in with the credentials used by lemmy.ml, and to log me into lemmy.ml instead, and then to be redirected to the 'local' version of the link on the lemmy.ml instance.
Rather than it just be a feddit.nl login page only, and be told 'log in not recognised'. That's where my confusion came from. I'm like "wait, I can't log into Lemmy here? why?!"
Copy paste the feddit.nl link into the Lemmy.ml search bar and search for it, it will fetch the post on Lemmy.ml
The whole linking to other instances and services like lemsha.re or lemmyverse.link within Lemmy should be fixed in the next release of Lemmy. It will include rewriting remote instance URLs to the local instance equivalent.
A community to talk about the Fediverse and all it's related services using ActivityPub (Mastodon, Lemmy, KBin, etc).
If you wanted to get help with moderating your own community then head over to !moderators@lemmy.world!
Learn more at these websites: Join The Fediverse Wiki, Fediverse.info, Wikipedia Page, The Federation Info (Stats), FediDB (Stats), Sub Rehab (Reddit Migration)