timingandestimationplugin doesn't work after a 1.2.2 to 1.4.2 trac upgrade

[guillaume22]

After successfully upgrading Trac from 1.2.2 to 1.4.2, I faced some issues regarding a few plugins, particularly with timingandestimationplugin. After trac-admin env/ upgrade, I get stuck in "Upgrading Database" step with this error:

2021-01-07 11:52:55,985 Trac[console] ERROR: Exception in trac-admin command: u'upgrade'
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/trac/admin/console.py", line 83, in onecmd
    rv = cmd.Cmd.onecmd(self, line) or 0
  File "/usr/lib/python2.7/cmd.py", line 220, in onecmd
    return self.default(line)
  File "/usr/local/lib/python2.7/dist-packages/trac/admin/console.py", line 252, in default
    return self.cmd_mgr.execute_command(*args)
  File "/usr/local/lib/python2.7/dist-packages/trac/admin/api.py", line 135, in execute_command
    return f(*fargs)
  File "/usr/local/lib/python2.7/dist-packages/trac/env.py", line 1062, in _do_upgrade
    self.env.upgrade(backup=no_backup is None)
  File "/usr/local/lib/python2.7/dist-packages/trac/env.py", line 787, in upgrade
    participant.upgrade_environment()
  File "build/bdist.linux-x86_64/egg/timingandestimationplugin/api.py", line 247, in upgrade_environment
    self.do_db_upgrade()
  File "build/bdist.linux-x86_64/egg/timingandestimationplugin/api.py", line 99, in do_db_upgrade
    dbhelper.set_system_value(self.env, self.db_version_key, self.db_version)
  File "build/bdist.linux-x86_64/egg/timingandestimationplugin/dbhelper.py", line 147, in set_system_value
    value, key)
  File "build/bdist.linux-x86_64/egg/timingandestimationplugin/dbhelper.py", line 46, in execute_non_query
    execute_in_trans(env, (sql, params))
  File "build/bdist.linux-x86_64/egg/timingandestimationplugin/dbhelper.py", line 83, in execute_in_trans
    raise e
ProgrammingError: (1064, u"You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'system (value, name) VALUES (6, 'TimingAndEstimationPlugin_Db_Version')' at line 1")

I tried upgrading the plugin from 1.3.7b0 (which worked correctly with Trac 1.2.2) to 1.6.0 and added a few hacks found in this ticket https://trac-hacks.org/ticket/13732, but the problem still persists. Any idea why?

My configuration:

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:84.0) Gecko/20100101 Firefox/84.0
Trac 	1.4.2
Babel 	2.6.0
Docutils 	0.16
Genshi 	0.7.3 (with speedups)
GIT 	2.25.1
Jinja2 	2.10.3
mod_wsgi 	4.6.8 (WSGIProcessGroup voxygen WSGIApplicationGroup %{GLOBAL})
MySQL 	server: "8.0.22-0ubuntu0.20.04.3", client: "0.10.1", thread-safe: True
Pygments 	2.3.1
pymysql 	0.10.1
Python 	2.7.18 (default, Aug 4 2020, 11:16:42) [GCC 9.3.0]
pytz 	2019.3
setuptools 	44.1.1
Subversion 	1.13.0 (r1867053)
jQuery	1.12.4
jQuery UI	1.12.1
jQuery Timepicker	1.6.3