The article on authentication problems refers to "the log" and the "server log" but lacks information on where to find that log or how to configure it.
This is another instance where the documentation basically assumes you have gotten here either already knowing how your specifics system's logging works or by following the flow of the chapter and using the default log output, which is specified not in configuration but on the command line of the server startup command described a couple of chapters back (v11 - 18.13.1). IOW, the configuration options are secondary ways of generating logging data on the server while the log mentioned here and elsewhere is the primary location (as defined on the pg_ctl command line).
I don't know that adding the link, easy as it is, is really necessary, and if the link is added I feel that just doing this may be insufficient.
But AFAICT the default log level/configuration does not cause the messages described on this page to be logged. So additional information on minimal log configuration is required.
I'm doubtful, but have not investigated, that the fatal messages described here are not being emitted by a server with default settings.
