Apple's newer syslog system


os_log           Sends a default-level message to the logging system. See Listing 1.
os_log_info      Sends an info-level message to the logging system. See Listing 2.
os_log_debug     Sends a debug-level message to the logging system. See Listing 3. 
                Note that debug-level messages are only captured when debug logging has been explicitly enabled 
                via the log command-line tool or a custom logging profile. See Customizing Logging Behavior While Debugging.
os_log_error    Sends an error-level message to the logging system.
os_log_fault     Logs a fault-level message to the logging system.



sudo log config --mode "level:debug" --subsystem com.your_company.your_subsystem_name


<a href=https://developer.apple.com/documentation/os/logging?preferredLanguage=occ>Developer Docs</a>