+GETTING DEBUG LOGGING FROM CUPS
+
+ When configured with the "--enable-debug-printfs" option, CUPS compiles in
+ additional debug logging support in the scheduler, CUPS API, and CUPS
+ Imaging API. The following environment variables are used to enable and
+ control debug logging:
+
+ CUPS_DEBUG_FILTER Specifies a POSIX regular expression to control
+ which messages are logged.
+ CUPS_DEBUG_LEVEL Specifies a number from 0 to 9 to control the
+ verbosity of the logging. The default level is 1.
+ CUPS_DEBUG_LOG Specifies a log file to use. Specify the name "-"
+ to send the messages to stderr. Prefix a filename
+ with "+" to append to an existing file.
+
+