Detach and assert on thread

Question

Refer below code:

https://code.sololearn.com/c26A4A14A24A

When we detach the thread object, it generates default thread ID. So, code will complete execution as assert statement is ok. This works ok and I believe my understanding is true.

Now change line related to detach to t1.join(); and it still does not give assert abort. Why so?

Answer 1

If I am trying to get id first and then attach or join, it gets aborted due to timeout in both scenarios