Created attachment 768821 [details] /var/log/cups/error_log using wrapper of smb backend Same action as before, but now I replaced "smb" backend with my own script which prints out all arguments and ENV variables. Wrapper script: >&2 echo "DEBUG_SMB" >&2 echo $0 $@ >&2 echo "" >&2 env See "[Job 116]" at line 240 and below. If this script passes all arguments to "/usr/bin/smbspool" as in "/usr/bin/smbspool $DEVICE_URI "$@"" printing works again as expected (note added $DEVICE_URI - but it might work even if I just add "" in its place).