jason@JS-Z835:~$ scp-dbus-service --debug
Service running...
Using polkit-1 connection class
+<asyncipp._IPPAuthOperation instance at 0x2c87680>
New IPPConnection
+<_IPPConnectionThread(Thread-1, initial daemon)>
+<asyncipp.IPPAuthConnection instance at 0x2cb16c8>
Awaiting further instructions
DevicesGet new API: True
+<asyncpk1.PK1Connection instance at 0x2cb1ab8>
+<asyncconn.Connection object at 0x2cba050>
+<__main__.GroupPhysicalDevicesRequest instance at 0x2ce27a0>
Kill timer stopped
Kill timer started
-<__main__.GroupPhysicalDevicesRequest instance at 0x2ce27a0>
+<__main__.GroupPhysicalDevicesRequest instance at 0x2ce27a0>
Kill timer stopped
Kill timer started
-<__main__.GroupPhysicalDevicesRequest instance at 0x2ce27a0>
+<__main__.GroupPhysicalDevicesRequest instance at 0x2ce27a0>
Kill timer stopped
Kill timer started
-<__main__.GroupPhysicalDevicesRequest instance at 0x2ce27a0>
+<__main__.GroupPhysicalDevicesRequest instance at 0x2ce27a0>
Kill timer stopped
Kill timer started
-<__main__.GroupPhysicalDevicesRequest instance at 0x2ce27a0>
+<__main__.GroupPhysicalDevicesRequest instance at 0x2ce27a0>
Kill timer stopped
+<dnssdresolve.DNSSDHostNamesResolver instance at 0x2ce28c0>
Resolving address for EPSON WorkForce 435._pdl-datastream._tcp.local
dnssd://EPSON%20WorkForce%20435._pdl-datastream._tcp.local/ is at 192.168.1.150 (EPSONCF7C79)
All addresses resolved
Kill timer started
-<__main__.GroupPhysicalDevicesRequest instance at 0x2ce27a0>
-<dnssdresolve.DNSSDHostNamesResolver instance at 0x2ce28c0>
+<__main__.GetBestDriversRequest instance at 0x2ce26c8>
Kill timer stopped
GetBestDrivers request: need to fetch PPDs
FetchPPDs: running
+<asyncconn._AsyncMethodCall instance at 0x2ce27a0>
<asyncconn._AsyncMethodCall instance at 0x2ce27a0>: calling <function binding at 0x2ce4c08>
+_PK1AsyncMethodCall: <asyncpk1._PK1AsyncMethodCall instance at 0x2ce27e8>
<asyncpk1._PK1AsyncMethodCall instance at 0x2ce27e8>: calling <function <lambda> at 0x2cd3ed8>
+<asyncipp._IPPAuthOperation instance at 0x2ce2d40>
Next task: (<method 'getPPDs2' of 'cups.Connection' objects>, (), {}, <bound method _PK1AsyncMethodCall._ipp_reply_handler of <asyncpk1._PK1AsyncMethodCall instance at 0x2ce27e8>>, <bound method _IPPAuthOperation.error_handler of <asyncipp._IPPAuthOperation instance at 0x2ce2d40>>, <bound method _IPPAuthOperation.auth_handler of <asyncipp._IPPAuthOperation instance at 0x2ce2d40>>)
-<asyncipp._IPPAuthOperation instance at 0x2c87680>
Call <method 'getPPDs2' of 'cups.Connection' objects>
...success
Awaiting further instructions
<asyncpk1._PK1AsyncMethodCall instance at 0x2ce27e8>: chaining up to <bound method _AsyncMethodCall.reply_handler of <asyncconn._AsyncMethodCall instance at 0x2ce27a0>>
<asyncconn._AsyncMethodCall instance at 0x2ce27a0>: to reply_handler at <bound method Connection._subst_reply_handler of <asyncconn.Connection object at 0x2cba050>>
DESTROY: <asyncconn._AsyncMethodCall instance at 0x2ce27a0>
<asyncconn.Connection object at 0x2cba050>: chaining up to <bound method FetchedPPDs._cups_getppds_reply of <FetchedPPDs object at 0x2ccb7d0 (__main__+FetchedPPDs at 0x29a0f20)>>
FetchPPDs: success
No ID match for device dnssd://EPSON%20WorkForce%20435._pdl-datastream._tcp.local/:
MFG:EPSON;MDL:WorkForce 435;
Fontconfig error: "/etc/fonts/conf.d/65-khmer.conf", line 14: out of memory
Fontconfig error: "/etc/fonts/conf.d/65-khmer.conf", line 23: out of memory
Fontconfig error: "/etc/fonts/conf.d/65-khmer.conf", line 32: out of memory
+<NewPrinterGUI object at 0x31e8690 (newprinter+NewPrinterGUI at 0x29a5280)>
Connected as user jason
Authentication pass: 1
Authentication: password callback set
Authentication pass: 1
Authentication: password callback set
nextNPTab: No exact driver match, querying OpenPrinting
nextNPTab: Searching for "MFG:EPSON;MDL:WorkForce 435;"
Querying drivers for Epson-WorkForce_435_Series
 - drivers found
 - drivers with installable resources found
All printer driver queries finished
Will fetch ppd? 0
Traceback (most recent call last):
  File "/usr/share/system-config-printer/newprinter.py", line 3678, in on_tvNPDownloadableDrivers_cursor_changed
    iter = model.get_iter (path)
  File "/usr/lib/python2.7/dist-packages/gi/overrides/Gtk.py", line 810, in get_iter
    path = self._coerce_path(path)
  File "/usr/lib/python2.7/dist-packages/gi/overrides/Gtk.py", line 785, in _coerce_path
    return TreePath(path)
  File "/usr/lib/python2.7/dist-packages/gi/overrides/Gtk.py", line 1135, in __new__
    path = ":".join(str(val) for val in path)
TypeError: 'NoneType' object is not iterable
{'freesoftware': True,
 'functionality': {'graphics': '100',
                   'lineart': '100',
                   'photo': '100',
                   'text': '100'},
 'license': 'GPL',
 'manufacturersupplied': True,
 'name': 'epson-escpr',
 'nonfreesoftware': False,
 'packages': {'amd64': {'epson-inkjet-printer-escpr_1.2.3-1lsb3.2_amd64.deb': {'fingerprint': 'https://intouch.ebz.epson.net/key/fingerprint',
                                                                               'pkgsys': 'deb',
                                                                               'realversion': '1.2.3',
                                                                               'release': '1',
                                                                               'repositories': {'apt': 'deb http://download.ebz.epson.net/dsc/op/stable/debian/ lsb3.2 main'},
                                                                               'url': 'http://download.ebz.epson.net/dsc/op/stable/debian/dists/lsb3.2/main/binary-amd64/epson-inkjet-printer-escpr_1.2.3-1lsb3.2_amd64.deb',
                                                                               'version': '1.2.3'}}},
 'patents': False,
 'recommended': False,
 'shortdescription': 'Epson Inkjet Printer Driver (ESC/P-R) for Linux',
 'supplier': 'Seiko Epson Corporation',
 'supportcontacts': [{'level': 'voluntary',
                      'name': 'Seiko Epson Corporation',
                      'url': 'http://download.ebz.epson.net/dsc/search/01/search/?OSC=LX'}],
 'thirdpartysupplied': False,
 'url': 'http://download.ebz.epson.net/dsc/search/01/search/?OSC=LX'}
{'freesoftware': True,
 'functionality': {'graphics': '100',
                   'lineart': '100',
                   'photo': '100',
                   'text': '100'},
 'license': 'GPL',
 'manufacturersupplied': True,
 'name': 'epson-escpr',
 'nonfreesoftware': False,
 'packages': {'amd64': {'epson-inkjet-printer-escpr_1.2.3-1lsb3.2_amd64.deb': {'fingerprint': 'https://intouch.ebz.epson.net/key/fingerprint',
                                                                               'pkgsys': 'deb',
                                                                               'realversion': '1.2.3',
                                                                               'release': '1',
                                                                               'repositories': {'apt': 'deb http://download.ebz.epson.net/dsc/op/stable/debian/ lsb3.2 main'},
                                                                               'url': 'http://download.ebz.epson.net/dsc/op/stable/debian/dists/lsb3.2/main/binary-amd64/epson-inkjet-printer-escpr_1.2.3-1lsb3.2_amd64.deb',
                                                                               'version': '1.2.3'}}},
 'patents': False,
 'recommended': False,
 'shortdescription': 'Epson Inkjet Printer Driver (ESC/P-R) for Linux',
 'supplier': 'Seiko Epson Corporation',
 'supportcontacts': [{'level': 'voluntary',
                      'name': 'Seiko Epson Corporation',
                      'url': 'http://download.ebz.epson.net/dsc/search/01/search/?OSC=LX'}],
 'thirdpartysupplied': False,
 'url': 'http://download.ebz.epson.net/dsc/search/01/search/?OSC=LX'}