jitsi-meet-prosody: Unable to load module 'roster_command': /usr/lib/prosody/modules/mod_roster_command.lua: No such file or directory

Probably introduced by merge/pull request https://github.com/jitsi/jitsi-meet/pull/8381.

Upgrading the package jitsi-meet-prosody to version 1.0.4638-1 fails:

$ sudo apt full-upgrade
[…]
Get:7 https://download.jitsi.org unstable/ jitsi-meet-prosody 1.0.4638-1 [43.2 kB]
[…]
Setting up jitsi-meet-prosody (1.0.4638-1) ...
Component "focus.jitsi.molgen.mpg.de" "client_proxy"
modulemanager       error	Unable to load module 'roster_command': /usr/lib/prosody/modules/mod_roster_command.lua: No such file or directory
Failed to load module 'roster_command': /usr/lib/prosody/modules/mod_roster_command.lua: No such file or directory
dpkg: error processing package jitsi-meet-prosody (--configure):
 installed jitsi-meet-prosody package post-installation script subprocess returned error exit status 1
dpkg: dependency problems prevent configuration of jitsi-meet-turnserver:
 jitsi-meet-turnserver depends on jitsi-meet-prosody; however:
  Package jitsi-meet-prosody is not configured yet.
[…]
$ dpkg -l jitsi-meet-prosody
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name               Version      Architecture Description
+++-==================-============-============-====================================
iF  jitsi-meet-prosody 1.0.4638-1   all          Prosody configuration for Jitsi Meet
$ dpkg -S /usr/share/jitsi-meet/prosody-plugins/mod_roster_command.lua
jitsi-meet-prosody: /usr/share/jitsi-meet/prosody-plugins/mod_roster_command.lua

[morlac]

I found a solution that worked for me: somewhere in the update-process the file /etc/prosody/prosody.cfg.lua changed and at the end of the file the line Include "conf.d/*.cfg.lua"was missing. Once I re-added this line the upgrade finished.

[sliderxtm]

Same on fresh install on Ubuntu 20.04.3 LTS:

modulemanager       error       Unable to load module 'roster_command': /usr/lib/prosody/modules/mod_roster_command.lua: No such file or directory                                                                                            
Failed to load module 'roster_command': /usr/lib/prosody/modules/mod_roster_command.lua: No such file or directory     

# cat /etc/prosody/prosody.cfg.lua | grep plugin
plugin_paths = { "/usr/local/lib/prosody/modules" }
-- It looks for mod_modulename.lua in the plugins folder, so make sure that exists too.

however:

# ls -la /usr/share/jitsi-meet/prosody-plugins/ | grep roster
-rw-r--r--  1 root root  5823 янв 25 19:38 mod_roster_command.lua
-rw-r--r--  1 root root  2486 янв 25 19:38 mod_roster_command.patch