Hello, don't file these often so apologies for any mistakes, trying to be good python citizen here.

Checked this on the python-list first, and others reported it as reproducible.

The issue is:
On Osx Monterey(12.x), Logging.handlers.SysLogHandler does not work.  It won't throw any error but the ASL/Console.App does not see any messages from it.  On OSX Big Sur (11.x) this works just fine with the exact same code.

I think I've cut this into a small example proof that can be run to demonstrate the issue.  If this is run and any of the substrings are searched for in Console.App when it is checking events, only the QQQ message from SysLog will show up.

Gonna work around it likely on our end, but hope this helps it get fixed for a future version.

---

import logging
from logging.handlers import SysLogHandler

root_logger = logging.getLogger()
root_logger.setLevel(logging.DEBUG)
basic_datefmt = '%m/%d/%Y %I:%M:%S %p'

syslog_format = logging.Formatter(fmt='SetupCDNGUI: %(message)s', datefmt=basic_datefmt)

sys_handler = SysLogHandler(address='/var/run/syslog')
#sys_handler.encodePriority(SysLogHandler.LOG_USER, SysLogHandler.LOG_ALERT)
# Tried with the above, but didn't make a difference.  Neither did not defining the address and letting it go to local host.
sys_handler.setFormatter(syslog_format)
root_logger.addHandler(sys_handler)


# None of these will show up.
logging.critical("CCC This is a test critical")
logging.error("EEE This is a test error")
logging.info("III Still a test")


# Comparatively this sends a message received just fine
import syslog

syslog.openlog(logoption=syslog.LOG_PID, facility=syslog.LOG_USER)
syslog.syslog(syslog.LOG_NOTICE, 'QQQ test log')