How to get the status icon of an entire project in Team City 10

Question

As the title says, I'm trying to get the status icon of an entire project (not just a build or a build configuration) in TC10.

For example, say I have the following project with build config structure:

PROJECT
 - BUILD CONFIG 1
    + BRANCH A (default) OK 
    + BRANCH B           OK
    + BRANCH C           OK
 - BUILD CONFIG 2
    + BRANCH A           OK 
    + BRANCH B           FAILED
    + BRANCH C           OK

I want that the icon shows a FAILED status, because one of the builds failed in my project.

I read the documentation at https://confluence.jetbrains.com/display/TCD10/REST+API#RESTAPI-BuildStatusIcon and, based on the examples, I came up with this URL:

https://server/app/rest/builds/aggregated/strob:
    (
     branch:(
             buildType:project(PROJECT_ID),
             policy:active_history_and_active_vcs_branches
            ),
     locator:(
             buildType:project:(PROJECT_ID)
             )
    )/statusIcon.svg

I "tested" this on 2 projects with the same structure and status as above, one of them shows a failed status, the other shows a success status. What's really puzzling me is that, if I look at the status of BUILD CONFIG 2 for both projects, they both show a FAILED status.

So I guess my question is:

• what URL should I use to get a unique status icon, for all builds on active branches, in a particular project ?

Thanks.