I think there might be a problem with the scriptlet as a whole. The version that exists in dbus-daemon looks different:

%pre daemon
# Add the "dbus" user and group
getent group dbus >/dev/null || groupadd -f -g %{dbus_user_uid} -r dbus
if ! getent passwd dbus >/dev/null ; then
    if ! getent passwd %{dbus_user_uid} >/dev/null ; then
      useradd -r -u %{dbus_user_uid} -g %{dbus_user_uid} -d '/' -s /sbin/nologin -c "System message bus" dbus
    else
      useradd -r -g %{dbus_user_uid} -d '/' -s /sbin/nologin -c "System message bus" dbus
    fi
fi
exit 0

I think there might be a problem with the scriptlet as a whole. The version that exists in dbus-daemon looks different:
[...]

This version also resolves the issue, I tested it. Should I update the PR to this variant?

I'm not tight to any solution, I just wanna see this issue fixed :)

Yeah, update this PR to this variant.

@jbrielmaier Please amend the commit to use the proposed scriptlet.

@jbrielmaier As for how to push to your own fork while being not being a packager, there's some special instructions: https://fedoraproject.org/wiki/Infrastructure/HTTPS-commits

Closing in favour of https://src.fedoraproject.org/rpms/dbus-broker/pull-request/3.

@ngompa There is no fedpkg on openSUSE, so I did it again over the WebUI :P