- MAC-then-encrypt algorithms were removed from the default selection of `services.openssh.settings.Macs`. If you still require these [MACs](https://en.wikipedia.org/wiki/Message_authentication_code), for example when you are relying on libssh2 (e.g. VLC) or the SSH library shipped on the iPhone, you can re-add them like this:

  ```nix
  {
    services.openssh.settings.Macs = [
      "hmac-sha2-512"
      "hmac-sha2-256"
      "umac-128@openssh.com"
    ];
  }
  ```

- `podman` now uses the `netavark` network stack. Users will need to delete all of their local containers, images, volumes, etc, by running `podman system reset --force` once before upgrading their systems.

- `git-bug` has been updated to at least version 0.8.0, which includes backwards incompatible changes. The `git-bug-migration` package can be used to upgrade existing repositories.

- `graylog` has been updated to version 5, which can not be updated directly from the previously packaged version 3.3. If you had installed the previously packaged version 3.3, please follow the [upgrade path](https://go2docs.graylog.org/5-0/upgrading_graylog/upgrade_path.htm) from 3.3 to 4.0 to 4.3 to 5.0.

- `buildFHSUserEnv` is now called `buildFHSEnv` and uses FlatPak's Bubblewrap sandboxing tool rather than Nixpkgs' own chrootenv. The old chrootenv-based implementation is still available via `buildFHSEnvChroot` but is considered deprecated and will be removed when the remaining uses inside Nixpkgs have been migrated. If your FHSEnv-wrapped application misbehaves when using the new bubblewrap implementation, please create an issue in Nixpkgs.

- `nushell` has been updated to at least version 0.77.0, which includes potential breaking changes in aliases. The old aliases are now available as `old-alias` but it is recommended you migrate to the new format. See [Reworked aliases](https://www.nushell.sh/blog/2023-03-14-nushell_0_77.html#reworked-aliases-breaking-changes-kubouch).

- `gajim` has been updated to version 1.7.3 which has disabled legacy ciphers. See [changelog for version 1.7.0](https://dev.gajim.org/gajim/gajim/-/releases/1.7.0).

- `keepassx` and `keepassx2` have been removed, due to upstream [stopping development](https://www.keepassx.org/index.html%3Fp=636.html). Consider [KeePassXC](https://keepassxc.org) as a maintained alternative.

- The [services.kubo.settings](#opt-services.kubo.settings) option is now no longer stateful. If you changed any of the options in [services.kubo.settings](#opt-services.kubo.settings) in the past and then removed them from your NixOS configuration again, those changes are still in your Kubo configuration file but will now be reset to the default. If you're unsure, you may want to make a backup of your configuration file (probably `/var/lib/ipfs/config`) and compare after the update.

- The Kubo HTTP API will no longer listen on localhost and will instead only listen on a Unix domain socket by default. Read the [services.kubo.settings.Addresses.API](#opt-services.kubo.settings.Addresses.API) option description for more information.

- The EC2 image module no longer fetches instance metadata in stage-1. This results in a significantly smaller initramfs, since network drivers no longer need to be included, and faster boots, since metadata fetching can happen in parallel with startup of other services.
  This breaks services which rely on metadata being present by the time stage-2 is entered. Anything which reads EC2 metadata from `/etc/ec2-metadata` should now have an `after` dependency on `fetch-ec2-metadata.service`

- The mailman service now defaults to using a randomly generated REST API password instead of a hard-coded one.

- `minio` removed support for its legacy filesystem backend in [RELEASE.2022-10-29T06-21-33Z](https://github.com/minio/minio/releases/tag/RELEASE.2022-10-29T06-21-33Z). This means if your storage was created with the old format, minio will no longer start. Unfortunately, minio doesn't provide an automatic migration, they only provide [instructions how to manually convert the node](https://min.io/docs/minio/windows/operations/install-deploy-manage/migrate-fs-gateway.html). To facilitate this migration, we keep around the last version that still supports the old filesystem backend as `minio_legacy_fs`. Use it via `services.minio.package = minio_legacy_fs;` to export your data before switching to the new version. See the corresponding [issue](https://github.com/NixOS/nixpkgs/issues/199318) for more details.