I have try last code, and find:
```
feng@debian:~ $ ./start_gnuhealth.sh
2022-01-12 01:22:54 [INFO] Starting GNU Health Server version 3.9.0 ...
Traceback (most recent call last):
File "/home/feng/gnuhealth/tryton/server/trytond-6.0.13/bin/./trytond", line 34, in <module>
Pool.start()
File "/home/feng/gnuhealth/tryton/server/trytond-6.0.13/trytond/pool.py", line 105, in start
register_classes()
File "/home/feng/gnuhealth/tryton/server/trytond-6.0.13/trytond/modules/__init__.py", line 339, in register_classes
for node in create_graph(get_module_list()):
File "/home/feng/gnuhealth/tryton/server/trytond-6.0.13/trytond/modules/__init__.py", line 157, in create_graph
raise MissingDependenciesException(list(missing))
trytond.exceptions.MissingDependenciesException: Missing dependencies: calendar
```
在 2022-01-12 02:01:38，"Luis Falcon" <falcon@gnuhealth.org> 写道：
>Happy 2022, Tumashu!
>
>On 1/11/22 00:53, tumashu wrote:
>>
>> feng@debian:~ $ ./start_gnuhealth.sh
>> "/home/feng/gnuhealth/tryton/server/trytond-6.0.13/trytond/modules/calendar/__init__.py",
>> line 17, in <module>
>> from .calendar_ import *
>> File
>> "/home/feng/gnuhealth/tryton/server/trytond-6.0.13/trytond/modules/calendar/calendar_.py",
>> line 20, in <module>
>> from .exceptions import (
>> ImportError: cannot import name 'InvalidRecurrence' from
>> 'trytond.modules.calendar.exceptions'
>
>Thanks for the feedback. Forgot to include some of the new exceptions
>classes definitions :)
>
>In addition to that, I'm refactoring quite a bit the caldav to comply
>with the GH naming and coding standards.
>
>I will commit later today to the default branch for testing.
>
>PS: Please remember that the packages "calendar" and "webdav" are not
>health_caldav and health_webdav3_server, throughout the whole GH HMIS.
>
>Bests,
>
>--
>Dr. Luis Falcon, MD, MSc
>President, GNU Solidario
>Advancing Social Medicine
>www.gnusolidario.org