If you don't write Async Rust code you can ignore this message.
Fuchsia's Async Rust executor now supports structured concurrency via the new Task Scope API. Task Scopes allow you to manage related tasks as a group. Here's an example of using the new API.
let scope = Scope::new();
scope.spawn(async {
    let result = Scope::new()
        .compute(async {
            let (a, b) = futures::join!(
                Scope::current().compute(delayed(1)),
                Scope::current().compute(delayed(1)),
            );
            a + b
        })
        .await;
    println!("1 + 1 = {result}");
});
scope.spawn(async {
    sleep(1).await;
    println!("Hello, world!");
});
scope.join().await;
zxdb async-backtrace supports task scopes too! Here's what the output looks like if we start the above code and immediately run the async-backtrace command:
[zxdb] async-backtrace
Task(id = 0)
└─ async_rust::main::func • async_rust.rs:31
   └─ fuchsia_async::scope::Join(0x807ae7d120)
Scope(0x807ae7d120)
└─ Task(id = 1)
   └─ async_rust::main::func::λ • async_rust.rs:24
      └─ fuchsia_async::Task(id = 3)
└─ Task(id = 2)
   └─ async_rust::main::func::λ • async_rust.rs:28
      └─ async_rust::sleep • async_rust.rs:35
         └─ fuchsia_async::runtime::fuchsia::timer::Timer
└─ Scope(0x807ae7cfd0)
   └─ Task(id = 3)
      └─ async_rust::main::func::λ::λ • join_mod.rs:95
         └─ join!
            └─ fuchsia_async::Task(id = 4)
            └─ fuchsia_async::Task(id = 5)
   └─ Task(id = 4)
      └─ async_rust::delayed • async_rust.rs:39
         └─ fuchsia_async::runtime::fuchsia::timer::Timer
   └─ Task(id = 5)
      └─ async_rust::delayed • async_rust.rs:39
         └─ fuchsia_async::runtime::fuchsia::timer::Timer
In this view you can easily see tasks nested within the scope that spawned them and scopes nested within other scopes. If your code already used TaskGroup or ExecutionScope, you're in luck: It is already backed by the new Scope API, and you can use the zxdb support today. Soon, uses of TaskGroup will be replaced with Scope.
The Scope API is already being used to simplify Fuchsia's Async Rust code and make it more reliable. Give it a try in your code and see if it works for you. Please leave feedback here or in the Rust on Fuchsia chat, and file bugs in the Language Platforms > Rust component.
Special thanks to Chris Suter for co-authoring and reviewing the implementation and API design.