Any further testers? Otherwise I'd merge tomorrow.

Sorry, still did not find time to deploy a Nextcloud instance.

there's a few nextcloud nixos tests, but I don't think they include any client logic. May be nice to add another to verify that the most common scenarios are supported.

@jtojnar do you still need a Nextcloud instance for testing purposes? If you lack time to do this, I could create a temporary Nextcloud setup on one of my servers :)

@Ma27 Hosting my own Nextcloud instance is on my to-do list. Deploying such a moloch declaratively will be ton of work, though. Or maybe I could use https://github.com/aszlig/avonc.

I lost my own instance during a nixpkgs update, I've registered to qcloud which worked yesterday but today, it shows "user disabled" when I try to login (in a browser). Otherwise the client builds and seems to run fine, I just couldn't test everything yet.

I lost my own instance during a nixpkgs update

May I ask what exactly went wrong? Although Nextcloud has its quirks, the NixOS module seems rather stable to me :)

I've registered to qcloud which worked yesterday but today, it shows "user disabled" when I try to login (in a browser).

yeah, they actually changed the login flow to do browser logins (so you don't have to enter your credentials every time if the login is remembered by the browser). But, as I've found several results to qcloud, would you mind telling me which one you mean?

Also, is this compatible to nextcloud (and is the error therefore relevant?).

I have no idea how my nextcloud db got deleted but this was a test server, I might have tried a nextcloud PR that was not ready yet or something completely different.
I solved the login issue with qloud.my (a nextcloud provider) and the client synchronizes correctly.
So feel free to merge.