Comment 3 for bug 1675515

The new option doesn't seem to be working correctly: https://github.com/rsyslog/rsyslog/issues/477

With the old style config:
#module(load="imklog" permitnonkernelfacility="on") # provides kernel logging support
$ModLoad imklog
#KLogPermitNonKernelFacility on

I get kernel messages in /var/log/syslog:
root@nsn7:~# grep andreas-was-here /var/log/syslog
root@nsn7:~# echo andreas-was-here > /dev/kmsg
root@nsn7:~# grep andreas-was-here /var/log/syslog
Jul 12 16:46:33 nsn7 kernel: [27774.476193] andreas-was-here
root@nsn7:~#

But with this new v6 config style:
module(load="imklog" permitnonkernelfacility="on") # provides kernel logging support
#$ModLoad imklog
#$KLogPermitNonKernelFacility on

I don't. Which is the github issue I mentioned.

Still, the ubuntu package is using a mix of old style vs new style when loading the imklog module, and that won't work anyway. We either go with v6 for both (loading and setting the option). or with legacy.