keystone-manage role list <tenant_name> does not return useful output

----- SETUP -----
# ./bin/keystone-manage tenant add test_tenant
SUCCESS: Tenant test_tenant created.
# ./bin/keystone-manage user add test_user password test_tenant
SUCCESS: User test_user created.
# ./bin/keystone-manage role add Admin
SUCCESS: Role Admin created successfully.
# ./bin/keystone-manage role add Member
SUCCESS: Role Member created successfully.
./bin/keystone-manage role grant Member test_user test_tenant
SUCCESS: Granted test_user the Member role on test_tenant.
-- END SETUP --

Using the above setup steps, the following output is basically useless from a CLI point of view:

# ./bin/keystone-manage role list test_tenantRole assignments for tenant test_tenant
User Role
-------------------------------------------------------------------------------
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