```
error package `log v0.4.19` cannot be built because it requires rustc 1.60.0 or newer, while the currently active rustc version is 1.56.1
```

```
error[E0635]: unknown feature `proc_macro_span_shrink`
  --> /home/runner/.cargo/registry/src/index.crates.io-6f17d22bba15001f/proc-macro2-1.0.52/src/lib.rs:92:30
   |
92 |     feature(proc_macro_span, proc_macro_span_shrink)
   |                              ^^^^^^^^^^^^^^^^^^^^^^
```

```
error: usage of `Arc<T>` where `T` is not `Send` or `Sync`
   --> futures-channel/src/mpsc/mod.rs:348:17
    |
348 |       let inner = Arc::new(BoundedInner {
    |  _________________^
349 | |         buffer,
350 | |         state: AtomicUsize::new(INIT_STATE),
351 | |         message_queue: Queue::new(),
...   |
354 | |         recv_task: AtomicWaker::new(),
355 | |     });
    | |______^
    |
    = help: consider using `Rc<T>` instead or wrapping `T` in a std::sync type like `Mutex<T>`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#arc_with_non_send_sync
    = note: `#[deny(clippy::arc_with_non_send_sync)]` on by default

error: usage of `Arc<T>` where `T` is not `Send` or `Sync`
   --> futures-channel/src/mpsc/mod.rs:379:17
    |
379 |       let inner = Arc::new(UnboundedInner {
    |  _________________^
380 | |         state: AtomicUsize::new(INIT_STATE),
381 | |         message_queue: Queue::new(),
382 | |         num_senders: AtomicUsize::new(1),
383 | |         recv_task: AtomicWaker::new(),
384 | |     });
    | |______^
    |
    = help: consider using `Rc<T>` instead or wrapping `T` in a std::sync type like `Mutex<T>`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#arc_with_non_send_sync

error: usage of `Arc<T>` where `T` is not `Send` or `Sync`
   --> futures-channel/src/oneshot.rs:105:17
    |
105 |     let inner = Arc::new(Inner::new());
    |                 ^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider using `Rc<T>` instead or wrapping `T` in a std::sync type like `Mutex<T>`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#arc_with_non_send_sync

error: could not compile `futures-channel` (lib) due to 3 previous errors

error: usage of `Arc<T>` where `T` is not `Send` or `Sync`
   --> futures-util/src/future/future/shared.rs:101:28
    |
101 |         Self { inner: Some(Arc::new(inner)), waker_key: NULL_WAKER_KEY }
    |                            ^^^^^^^^^^^^^^^
    |
    = help: consider using `Rc<T>` instead or wrapping `T` in a std::sync type like `Mutex<T>`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#arc_with_non_send_sync
    = note: `#[deny(clippy::arc_with_non_send_sync)]` on by default

error: usage of `Arc<T>` where `T` is not `Send` or `Sync`
   --> futures-util/src/stream/futures_unordered/mod.rs:131:34
    |
131 |           let ready_to_run_queue = Arc::new(ReadyToRunQueue {
    |  __________________________________^
132 | |             waker: AtomicWaker::new(),
133 | |             head: AtomicPtr::new(stub_ptr as *mut _),
134 | |             tail: UnsafeCell::new(stub_ptr),
135 | |             stub,
136 | |         });
    | |__________^
    |
    = help: consider using `Rc<T>` instead or wrapping `T` in a std::sync type like `Mutex<T>`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#arc_with_non_send_sync

error: usage of `Arc<T>` where `T` is not `Send` or `Sync`
  --> futures-util/src/lock/bilock.rs:64:19
   |
64 |           let arc = Arc::new(Inner {
   |  ___________________^
65 | |             state: AtomicPtr::new(ptr::null_mut()),
66 | |             value: Some(UnsafeCell::new(t)),
67 | |         });
   | |__________^
   |
   = help: consider using `Rc<T>` instead or wrapping `T` in a std::sync type like `Mutex<T>`
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#arc_with_non_send_sync
```

```
warning: explicit call to `.into_iter()` in function argument accepting `IntoIterator`
  --> futures/tests/stream_select_all.rs:83:38
   |
83 | ...ec![stream::iter(vec![1].into_iter()), stream::iter(vec![2].i...
   |                     ^^^^^^^^^^^^^^^^^^^ help: consider removing the `.into_iter()`: `vec![1]`
   |
note: this parameter accepts any `IntoIterator`, so you don't need to call `.into_iter()`
  --> /Users/taiki/projects/sources/rust-lang/futures-rs/futures-util/src/stream/iter.rs:31:8
   |
31 |     I: IntoIterator,
   |        ^^^^^^^^^^^^
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_conversion
   = note: `#[warn(clippy::useless_conversion)]` on by default

warning: explicit call to `.into_iter()` in function argument accepting `IntoIterator`
  --> futures/tests/stream_select_all.rs:83:73
   |
83 | ...)), stream::iter(vec![2].into_iter())]);
   |                     ^^^^^^^^^^^^^^^^^^^ help: consider removing the `.into_iter()`: `vec![2]`
   |
note: this parameter accepts any `IntoIterator`, so you don't need to call `.into_iter()`
  --> /Users/taiki/projects/sources/rust-lang/futures-rs/futures-util/src/stream/iter.rs:31:8
   |
31 |     I: IntoIterator,
   |        ^^^^^^^^^^^^
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_conversion

warning: explicit call to `.into_iter()` in function argument accepting `IntoIterator`
  --> futures/tests/stream_select_all.rs:91:29
   |
91 |     tasks.push(stream::iter(vec![3].into_iter()));
   |                             ^^^^^^^^^^^^^^^^^^^ help: consider removing the `.into_iter()`: `vec![3]`
   |
note: this parameter accepts any `IntoIterator`, so you don't need to call `.into_iter()`
  --> /Users/taiki/projects/sources/rust-lang/futures-rs/futures-util/src/stream/iter.rs:31:8
   |
31 |     I: IntoIterator,
   |        ^^^^^^^^^^^^
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_conversion

warning: explicit call to `.into_iter()` in function argument accepting `IntoIterator`
   --> futures/tests/async_await_macros.rs:325:41
    |
325 | ...ct!(stream::iter(vec![1].into_iter()), stream::iter(vec![1]....
    |                     ^^^^^^^^^^^^^^^^^^^ help: consider removing the `.into_iter()`: `vec![1]`
    |
note: this parameter accepts any `IntoIterator`, so you don't need to call `.into_iter()`
   --> /Users/taiki/projects/sources/rust-lang/futures-rs/futures-util/src/stream/iter.rs:31:8
    |
31  |     I: IntoIterator,
    |        ^^^^^^^^^^^^
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_conversion
    = note: `#[warn(clippy::useless_conversion)]` on by default

warning: explicit call to `.into_iter()` in function argument accepting `IntoIterator`
   --> futures/tests/async_await_macros.rs:325:76
    |
325 | ...)), stream::iter(vec![1].into_iter()));
    |                     ^^^^^^^^^^^^^^^^^^^ help: consider removing the `.into_iter()`: `vec![1]`
    |
note: this parameter accepts any `IntoIterator`, so you don't need to call `.into_iter()`
   --> /Users/taiki/projects/sources/rust-lang/futures-rs/futures-util/src/stream/iter.rs:31:8
    |
31  |     I: IntoIterator,
    |        ^^^^^^^^^^^^
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_conversion
```