lander attempts to get binaries crashes

After submitting a successful ticket with binaries, the next ticket fails with the crash seen below. The lander is expecting the ticket binaries API to return a list, but it's a dict.

[Actual API return]
{"meta": {"limit": 20, "next": null, "offset": 0, "previous": null, "total_count": 1}, "objects": [{"id": 1, "name": "libgsl0ldbl", "resource_uri": "/api/v1/binarypackage/1/"}]}

[lander_iamge_builder.log]
Started by upstream project "lander_master" build number 2
originally caused by:
 Started by remote host 10.0.0.55
Building in workspace /var/lib/jenkins/jobs/lander_image_builder/workspace
[workspace] $ /bin/bash /tmp/hudson649222980570900500.sh
+ '[' -d results ']'
+ rm -rf results
+ mkdir results
+ sed 's/\\/\\\\/g'
+ echo '{"bsbuilder":' '{"ppa":' '"ppa:fginther/ci-pool-002",' '"artifacts":' '[{"type":' '"LOGS",' '"name":' '"package_build.output.log",' '"reference":' '"https://region-a.geo-1.objects.hpcloudsvc.com/v1/11740916806557/ticket-2/package_build.output.log"}],' '"state":' '"COMPLETED",' '"exit":' true, '"result":' '"PASSED",' '"message":' '"The' package build was 'successful.",' '"archive":' '"ppa:fginther/ci-archive",' '"subticket_status":' '[{"status":' 230, '"resource":' '"/api/v1/fullsubticket/2/",' '"name":' '"lapack",' '"artifacts":' '[{"type":' '"LOGS",' '"name":' '"package_build.lapack.amd64.build.log",' '"reference":' '"https://region-a.geo-1.objects.hpcloudsvc.com/v1/11740916806557/ticket-2/package_build.lapack.amd64.build.log"},' '{"type":' '"LOGS",' '"name":' '"package_build.lapack.i386.build.log",' '"reference":' '"https://region-a.geo-1.objects.hpcloudsvc.com/v1/11740916806557/ticket-2/package_build.lapack.i386.build.log"}],' '"step_text":' '"Completed",' '"step":' 1000, '"version":' '"3.4.2+dfsg-2ubuntu1~fginther.20140313.1",' '"message":' '"The' source packages have been built in 'https://launchpad.net/~fginther/+archive/ci-pool-002.",' '"status_text":' '"Completed",' '"id":' '2}]},' '"master":' '{"ppa_assigner_url":' '"http://10.0.0.57:8080",' '"progress_trigger":' '"lander_master-2",' '"imgbuilder_url":' '"http://10.0.0.53:8080",' '"tr_url":' '"http://10.0.0.61:8080",' '"bsb_url":' '"http://10.0.0.51:8080",' '"request_id":' '"2",' '"ts_url":' '"http://10.0.0.62:8080"},' '"ppa_assigner":' '{"ppa":' '"ppa:fginther/ci-pool-002",' '"result":' '"PASSED",' '"location":' '"http://10.0.0.57:8080/api/v1/ppa/2/"}}'
+ cat
++ cat params.json
++ sed 's/"//g'
++ grep -Po '(?<=ts_url": )"http:.*?"'
+ /srv/lander_jenkins_sub/lander/bin/lander_service_wrapper.py --input-file params.json --output-file results/params.json --service image_builder
21:58:57 DEBUG lander_service_wrapper: Executing service wrapper: image_builder
21:58:58 ERROR root: Unexpected error: unhashable type: 'dict'
Traceback (most recent call last):
  File "/srv/lander_jenkins_sub/lander/bin/lander_service_wrapper.py", line 400, in main
    results = handler(args)
  File "/srv/lander_jenkins_sub/lander/bin/lander_service_wrapper.py", line 266, in _handle_image_builder
    'package_list': _get_binary_packages(ticket, request_parameters),
  File "/srv/lander_jenkins_sub/lander/bin/lander_service_wrapper.py", line 213, in _get_binary_packages
    package_list = set(ticket.get_binaries())
TypeError: unhashable type: 'dict'
Build step 'Execute shell' marked build as failure
Archiving artifacts
Triggering a new build of lander_archiver #9
Finished: FAILURE