nextcloud20: drop

The version 20 of Nextcloud will be EOLed by the end of this month[1].

Since the recommended default (that didn't raise an eval-warning) on
21.05 was Nextcloud 21, this shouldn't affect too many people.

In order to ensure that nobody does a (not working) upgrade across
several major-versions of Nextcloud, I replaced the derivation of
`nextcloud20` with a `throw` that provides instructions how to proceed.

The only case that I consider "risky" is a setup upgraded from 21.05 (or
older) with a `system.stateVersion` <21.11 and with
`services.nextcloud.package` not explicitly declared in its config. To
avoid that, I also left the `else-if` for `stateVersion < 21.03` which
now sets `services.nextcloud.package` to `pkgs.nextcloud20` and thus
leads to an eval-error. This condition can be removed
as soon as 21.05 is EOL because then it's safe to assume that only
21.11. is used as stable release where no Nextcloud <=20 exists that can
lead to such an issue.

It can't be removed earlier because then every `system.stateVersion <
21.11` would lead to `nextcloud21` which is a problem if `nextcloud19`
is still used.

[1] https://docs.nextcloud.com/server/20/admin_manual/release_schedule.html

1 files changed, 1 insertions, 1 deletions

diff --git a/nixos/tests/nextcloud/default.nix b/nixos/tests/nextcloud/default.nix
index 65043e509b3..bd7a7aacdc9 100644
--- a/nixos/tests/nextcloud/default.nix
+++ b/nixos/tests/nextcloud/default.nix
@@ -18,4 +18,4 @@ foldl
     };
   })
   {}
-  [ 20 21 22 ]
+  [ 21 22 ]