After enable debugging I get these messages in the error logs
d [28/Feb/2023:09:10:04 +1100] [Client 25] cupsdWriteClient error=0, used=0, state=HTTP_POST_SEND, data_encoding=HTTP_ENCODE_LENGTH, data_remaining=9109, response=0x
56469ecf5b40(IPP_ATTRIBUTE), pipe_pid=0, file=-1
d [28/Feb/2023:09:10:04 +1100] [Client 23] cupsdWriteClient error=0, used=0, state=HTTP_POST_SEND, data_encoding=HTTP_ENCODE_LENGTH, data_remaining=11694, response=0
x56469ed70540(IPP_ATTRIBUTE), pipe_pid=0, file=-1
d [28/Feb/2023:09:10:04 +1100] select_timeout: JobHistoryUpdate=1677606292
d [28/Feb/2023:09:10:04 +1100] [Client 25] cupsdWriteClient error=0, used=0, state=HTTP_POST_SEND, data_encoding=HTTP_ENCODE_LENGTH, data_remaining=9084, response=0x
56469ecf5b40(IPP_ATTRIBUTE), pipe_pid=0, file=-1
d [28/Feb/2023:09:10:04 +1100] [Client 23] cupsdWriteClient error=0, used=0, state=HTTP_POST_SEND, data_encoding=HTTP_ENCODE_LENGTH, data_remaining=11671, response=0
x56469ed70540(IPP_ATTRIBUTE), pipe_pid=0, file=-1
d [28/Feb/2023:09:10:04 +1100] select_timeout: JobHistoryUpdate=1677606292
d [28/Feb/2023:09:10:04 +1100] [Client 25] cupsdWriteClient error=0, used=0, state=HTTP_POST_SEND, data_encoding=HTTP_ENCODE_LENGTH, data_remaining=9063, response=0x
56469ecf5b40(IPP_ATTRIBUTE), pipe_pid=0, file=-1
d [28/Feb/2023:09:10:04 +1100] [Client 23] cupsdWriteClient error=0, used=0, state=HTTP_POST_SEND, data_encoding=HTTP_ENCODE_LENGTH, data_remaining=11619, response=0
x56469ed70540(IPP_ATTRIBUTE), pipe_pid=0, file=-1
d [28/Feb/2023:09:10:04 +1100] select_timeout: JobHistoryUpdate=1677606292
d [28/Feb/2023:09:10:04 +1100] [Client 25] cupsdWriteClient error=0, used=0, state=HTTP_POST_SEND, data_encoding=HTTP_ENCODE_LENGTH, data_remaining=9038, response=0x
56469ecf5b40(IPP_ATTRIBUTE), pipe_pid=0, file=-1
d [28/Feb/2023:09:10:04 +1100] [Client 23] cupsdWriteClient error=0, used=0, state=HTTP_POST_SEND, data_encoding=HTTP_ENCODE_LENGTH, data_remaining=11585, response=0
x56469ed70540(IPP_ATTRIBUTE), pipe_pid=0, file=-1
d [28/Feb/2023:09:10:04 +1100] select_timeout: JobHistoryUpdate=1677606292
There’s also these messages
d [28/Feb/2023:09:10:04 +1100] cupsdAddSelect(fd=23, read_cb=0x56469e2dbb40, write_cb=(nil), data=0x56469ed41400)
D [28/Feb/2023:09:10:04 +1100] cupsdSetBusyState: newbusy="Printing jobs and dirty files", busy="Active clients, printing jobs, and dirty files"
d [28/Feb/2023:09:10:04 +1100] select_timeout: JobHistoryUpdate=1677606292
d [28/Feb/2023:09:10:04 +1100] [Client 25] cupsdReadClient error=0, used=0, state=HTTP_WAITING, data_encoding=HTTP_ENCODE_LENGTH, data_remaining=0, request=(nil)(),
file=-1
D [28/Feb/2023:09:10:04 +1100] [Client 25] POST / HTTP/1.1
D [28/Feb/2023:09:10:04 +1100] cupsdSetBusyState: newbusy="Active clients, printing jobs, and dirty files", busy="Printing jobs and dirty files"
d [28/Feb/2023:09:10:04 +1100] cupsdFindBest: uri = "/"...
d [28/Feb/2023:09:10:04 +1100] cupsdFindBest: Location /admin/conf Limit 7f
d [28/Feb/2023:09:10:04 +1100] cupsdFindBest: Location /admin Limit 7f
d [28/Feb/2023:09:10:04 +1100] cupsdFindBest: Location / Limit 7f
d [28/Feb/2023:09:10:04 +1100] cupsdFindBest: best = /
d [28/Feb/2023:09:10:04 +1100] [Client 25] con->uri="/", con->best=0x56469eae4150(/)
d [28/Feb/2023:09:10:04 +1100] [Client 25] Authorization=""
D [28/Feb/2023:09:10:04 +1100] [Client 25] No authentication data provided.
d [28/Feb/2023:09:10:04 +1100] cupsdIsAuthorized: con->uri="/", con->best=0x56469eae4150(/)
d [28/Feb/2023:09:10:04 +1100] cupsdIsAuthorized: level=CUPSD_AUTH_ANON, type=None, satisfy=CUPSD_AUTH_SATISFY_ALL, num_names=0
d [28/Feb/2023:09:10:04 +1100] cupsdIsAuthorized: auth=CUPSD_AUTH_ALLOW...
d [28/Feb/2023:09:10:04 +1100] [Client 25] cupsdReadClient error=0, used=67, state=HTTP_POST_RECV, data_encoding=HTTP_ENCODE_LENGTH, data_remaining=67, request=0x564
69ed70540(IPP_ATTRIBUTE), file=-1
d [28/Feb/2023:09:10:04 +1100] select_timeout: JobHistoryUpdate=1677606292
d [28/Feb/2023:09:10:04 +1100] [Client 25] cupsdReadClient error=0, used=38, state=HTTP_POST_RECV, data_encoding=HTTP_ENCODE_LENGTH, data_remaining=38, request=0x564
69ed70540(IPP_ATTRIBUTE), file=-1
d [28/Feb/2023:09:10:04 +1100] select_timeout: JobHistoryUpdate=1677606292
d [28/Feb/2023:09:10:04 +1100] [Client 25] cupsdReadClient error=0, used=1, state=HTTP_POST_RECV, data_encoding=HTTP_ENCODE_LENGTH, data_remaining=1, request=0x56469
ed70540(IPP_ATTRIBUTE), file=-1
D [28/Feb/2023:09:10:04 +1100] [Client 25] 1.1 CUPS-Get-Default 611583704
d [28/Feb/2023:09:10:04 +1100] cupsdProcessIPPRequest(0x56469edaf920[25]): operation_id = 4001
D [28/Feb/2023:09:10:04 +1100] CUPS-Get-Default
d [28/Feb/2023:09:10:04 +1100] get_default(0x56469edaf920[25])
d [28/Feb/2023:09:10:04 +1100] cupsdFindPolicyOp(p=0x56469eae96c0, op=4001(CUPS-Get-Default))
d [28/Feb/2023:09:10:04 +1100] cupsdFindPolicyOp: Found wildcard match...
d [28/Feb/2023:09:10:04 +1100] cupsdIsAuthorized: con->uri="/", con->best=0x56469eaee0d0((null))
d [28/Feb/2023:09:10:04 +1100] cupsdIsAuthorized: level=CUPSD_AUTH_ANON, type=None, satisfy=CUPSD_AUTH_SATISFY_ALL, num_names=0
d [28/Feb/2023:09:10:04 +1100] cupsdIsAuthorized: op=0(0x0000)
d [28/Feb/2023:09:10:04 +1100] cupsdIsAuthorized: auth=CUPSD_AUTH_ALLOW...
D [28/Feb/2023:09:10:04 +1100] CUPS-Get-Default client-error-not-found: No default printer.
D [28/Feb/2023:09:10:04 +1100] Returning IPP client-error-not-found for CUPS-Get-Default (no URI) from localhost
d [28/Feb/2023:09:10:04 +1100] cupsdProcessIPPRequest: ippLength(response)=113
d [28/Feb/2023:09:10:04 +1100] cupsdAddSelect(fd=25, read_cb=0x56469e2dbb40, write_cb=0x56469e2db420, data=0x56469edaf920)
d [28/Feb/2023:09:10:04 +1100] select_timeout: JobHistoryUpdate=1677606292
d [28/Feb/2023:09:10:04 +1100] select_timeout(0): 10 seconds to write dirty config/state files
Other parts of the error logs include these
d [28/Feb/2023:09:10:04 +1100] printer-uri-supported="ipp://localhost:631/printers/lilfin1"
d [28/Feb/2023:09:10:04 +1100] copy_attrs(to=0x56469ed67d30, from=0x56469eb15970, ra=0x56469ed89930, group=0, quickcopy=0)
d [28/Feb/2023:09:10:04 +1100] copy_attrs(to=0x56469ed67d30, from=0x56469eb148f0, ra=0x56469ed89930, group=0, quickcopy=0)
d [28/Feb/2023:09:10:04 +1100] copy_attrs(to=0x56469ed67d30, from=0x56469eaf73c0, ra=0x56469ed89930, group=0, quickcopy=-2147483648)
d [28/Feb/2023:09:10:04 +1100] add_printer_state_reasons(0x56469edaf920[25], 0x56469eb16600[lilnewcars1])
d [28/Feb/2023:09:10:04 +1100] printer-uri-supported="ipp://localhost:631/printers/lilnewcars1"
d [28/Feb/2023:09:10:04 +1100] copy_attrs(to=0x56469ed67d30, from=0x56469eb16e00, ra=0x56469ed89930, group=0, quickcopy=0)
d [28/Feb/2023:09:10:04 +1100] copy_attrs(to=0x56469ed67d30, from=0x56469eb15d40, ra=0x56469ed89930, group=0, quickcopy=0)
d [28/Feb/2023:09:10:04 +1100] copy_attrs(to=0x56469ed67d30, from=0x56469eaf73c0, ra=0x56469ed89930, group=0, quickcopy=-2147483648)
d [28/Feb/2023:09:10:04 +1100] add_printer_state_reasons(0x56469edaf920[25], 0x56469eb17aa0[lilparts1])