It's because of default php versions on Debian:
Debian 10 - php 7.3
Debian 11 - php 7.4
Debian 12 - php 8.2

Debian OS version doesn't matter.

Looks like a duplication.

Duplicated see T7247

you could try direct with apt install
it is in repository!
https://obs.kolabsys.com/repositories/Kolab:/16/Debian_10.0/all/roundcubemail-plugin-contextmenu_3.0-0~kolab13_all.deb

Distribution?
Manually tried to install the package? (apt yum dnf...)
It's definetly not a bug, it's a feature request (plugin).
It shouldn't be installed automatically, but mentioned as recommended.

wallace error mentioned here: T7247#100099

@waadaa85 : Did you try to limit synchronous (+S) and asynchronous (+A) threads?

python3 ./kolab-cli.py lm
should show list but is empty on actual git version

Debian11 Install is testing....
check error with existing tasks on bug list.
As PHP and Python3 needs upgrades to newer versions, shipped with new distributions, there are still rough corners and known errors.

Thanks for the debugging

adding:
deb http://obs.kolabsys.com/repositories/Kolab:/16/Debian_11.0/ ./
deb http://obs.kolabsys.com/repositories/Kolab:/Winterfell/Debian_11.0/ ./
deb http://obs.kolabsys.com/repositories/Kolab:/16:/Testing/Debian_11.0/ ./
'changed the typo'

with D3884 D3863 D3710 some rough corners should work again.
as "/Personal Calendar" "/Personal Contacts"

Work for for newer Distributions are still in progress!

work is in progress

Which readme? used repository? OS version, installed package version?
Some more information to help accordingly is appreciated.
So help could only be in general, with some information and more manuals to read.

abandoned by error

a comma was deleted by an error and fixed

Using text strings in cyruslib.py module is not very suitable:

quote is set now in cyruslib.py line 564

Some small adjustments on dscreate data and comments

The fix is accepted into git.
But as I ran into another Error, you should also use the latest Diff 11060.

I ran into an integer error on other tests,
so I corrected this with this patch.

res.append(c)

Just remove chr()
c is single character of a string, but not an integer value of a character.
I could see via grep, decode(s) is used with folders in modules used for imap

changed line 285 by a mistake, just split with \ as line to long

dscreate depends on python3-lib389, you will run into error, if you start setup with Python 2.
I run into this on Debian 10
Ubuntu 22.04 LTS has dscreate only for install and cockpit module would be the new admin, .pl scripts are dropped.

D3692 and D3710 should fix this
I ran into same error, when testing for Python 3

removed comitted code

dropped old imports in try..except lesser than 2.7
try...except removed

try...except
and old or unused imports
removed as explained

encode and decode becomes obsolete at the return value as sql, sql alchemy should do the encoding/decoding
see also:

class Entry
    def __init__

line 70-75 checks unicode

sqlalchemy.interfaces.PoolListener in pykolab/telemetry.py is deprecated since v0.7 and removed in v1.4
gettext.lgettext is removed in Python v 3.10

external cyruslib.py not python3 compatible.

streams ( Python 2 -> type { str } (bytes string) | Python 3 -> type { class bytes } ) uneven
encode() ( Python 2 -> type { str } (bytes string) | Python 3 -> type { class bytes } ) uneven
decode() ( Python 2 -> type { str } (text string) | Python 3 -> type { class string } ) even

this is for python 3 as there is more strict type operations between byte and text strings.
https://docs.python.org/3/howto/pyporting.html#text-versus-binary-data

Here is my debugging with python2.7 -3 ./saslauthd.py -d 9
and log. INFO before the trouble line:
logger.py

saslauthd.py -d 9
The root cause is that level is set from third party ldap and sqlalchemy logging, which are not of type (int).
pykolab/logger.py:271: DeprecationWarning: comparing unequal types not supported in 3.x

with --fork

testsaslauthd -u user(@domain) -p password
0: NO "authentication failed"

• Logging error ---

Traceback (most recent call last):

File "/usr/lib/python3.x/logging/__init__.py", line 1037, in emit
  stream.write(msg + self.terminator)

BrokenPipeError: [Errno 32] Broken pipe
Call stack:

File "./saslauthd.py", line 43, in <module>
  saslauthd.run()

...
Message: "Authentication for 'user(@domain)' succeeded"

I'll just change line 22

removed line at pykolab/cli/__init__.py

[Python 3]basestring to six string_types D3403

some manuals of interest:
Cheat-Sheet: Writing Python 2-3 compatible code:
https://python-future.org/compatible_idioms.html

gettext.lgettext removed in 3.10 D3367

some module names changed in python3 D3355