TestRun on parent test plan, does not include test cases of child test plans

[rejuce]

Description of problem

I have a parent testplan, that has no test, but several child test plans linked to it.
I would assume creating a test run from that parent test plan, includes all test cases from its children.
The test run does not contain any test cases though

Version or commit hash (if applicable)

docker:latest

Steps to Reproduce

1. create parent test plan
2. clone and make children
3. add test cases to child test plans
4. make run from parent

Actual results

run is empty and does not contain any cases

Expected results

run contains all test cases from all its children

[tagoylo]

I'm also trying to do something like this. Is this feature not supported?

[rejuce]

we found that testplan hirchaies are quite unuseable at the current state, because not only does running them not work properly, but also cloneing them does not work either, so we did not find a way to clone a parent and its children...