Created attachment 768819 [details]
/var/log/cups/error_log using normal /usr/lib/cups/backend/smb
This file is CUPS (in debug mode) error log file captured after trying to print
"Test Page" from CUPS web interface.
Note "[Job 115]" and line 800 which says: "Usage: smb://<MY_PRINTER_URI>
[DEVICE_URI] job-id user title copies options [file]" and few next lines
continue to describe usage of "/usr/bin/smbspool"