The same issue
2020-06-02 12:46:44.170 130 INFO rally.task.context [-] Task 232bbbe2-26f2-445d-b731-ab4821edd3f2 | Context users@openstack cleanup() finished in 4.31 sec
2020-06-02 12:46:45.040 130 INFO rally.task.engine [-] Load duration is: 0.0
2020-06-02 12:46:45.040 130 INFO rally.task.engine [-] Full runner duration is: 0.0
2020-06-02 12:46:45.043 130 INFO rally.task.engine [-] Full duration is: 29.443483
2020-06-02 12:46:45.081 130 ERROR rally.task.engine [-] Unexpected exception during the workload execution: InvalidScenarioArgument: Invalid scenario argument: 'Glance_Image with name 'cirros-0.3.5-x86_64-disk.img' is ambiguous, possible matches by id: 3534edaa-be1c-4eb5-90af-300782e9de2c, 1fd3ca13-5acd-4861-9e44-be77b7e7d626'
2020-06-02 12:46:45.081 130 ERROR rally.task.engine Traceback (most recent call last):
2020-06-02 12:46:45.081 130 ERROR rally.task.engine   File "/usr/local/lib/python2.7/dist-packages/rally/task/engine.py", line 515, in _run_workload
2020-06-02 12:46:45.081 130 ERROR rally.task.engine     workload["args"])
2020-06-02 12:46:45.081 130 ERROR rally.task.engine   File "/usr/local/lib/python2.7/dist-packages/rally/task/runner.py", line 164, in run
2020-06-02 12:46:45.081 130 ERROR rally.task.engine     args = types.preprocess(name, context, args)
2020-06-02 12:46:45.081 130 ERROR rally.task.engine   File "/usr/local/lib/python2.7/dist-packages/rally/task/types.py", line 87, in preprocess
2020-06-02 12:46:45.081 130 ERROR rally.task.engine     resource_spec=processed_args[src], config=type_cfg)
2020-06-02 12:46:45.081 130 ERROR rally.task.engine   File "/usr/local/lib/python2.7/dist-packages/rally_openstack/types.py", line 204, in pre_process
2020-06-02 12:46:45.081 130 ERROR rally.task.engine     resource = self._find_resource(resource_spec, images)
2020-06-02 12:46:45.081 130 ERROR rally.task.engine   File "/usr/local/lib/python2.7/dist-packages/rally_openstack/types.py", line 95, in _find_resource
2020-06-02 12:46:45.081 130 ERROR rally.task.engine     matching_exact))})
2020-06-02 12:46:45.081 130 ERROR rally.task.engine InvalidScenarioArgument: Invalid scenario argument: 'Glance_Image with name 'cirros-0.3.5-x86_64-disk.img' is ambiguous, possible matches by id: 3534edaa-be1c-4eb5-90af-300782e9de2c, 1fd3ca13-5acd-4861-9e44-be77b7e7d626'
2020-06-02 12:46:45.081 130 ERROR rally.task.engine 

but I have only one cirros-0.3.5-x86_64-disk.img image
ubuntu@useful-mayfly:~$ ./venv/bin/openstack --insecure image list
+--------------------------------------+------------------------------+--------+
| ID                                   | Name                         | Status |
+--------------------------------------+------------------------------+--------+
| 8e40c45a-ef4c-4c74-8602-7ecdb3d832f1 | Cirros-5.1                   | active |
| b38c4f5b-15ca-4f85-ba1d-cd44e02288fc | Fedora-27-1.6                | active |
| ecea22f1-9d48-4220-a7d8-cabf37b807db | TestVM                       | active |
| 15fbf7bd-9eac-4d3f-baf2-5124c2496a29 | amphora-x64-haproxy          | active |
| 1fd3ca13-5acd-4861-9e44-be77b7e7d626 | cirros-0.3.5-x86_64-disk.img | active |
+--------------------------------------+------------------------------+--------+