[INFO] cloning repository https://github.com/cmhteixeira/little-book-of-semaphores-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/cmhteixeira/little-book-of-semaphores-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcmhteixeira%2Flittle-book-of-semaphores-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcmhteixeira%2Flittle-book-of-semaphores-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 46a3e8c4a348c7c722ff75a3d9c780512dcd4d7e
[INFO] checking cmhteixeira/little-book-of-semaphores-rust against try#f47dd4da3ae8c32c9e65d307bfe640b143e674df for pr-77526
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcmhteixeira%2Flittle-book-of-semaphores-rust" "/workspace/builds/worker-8/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/cmhteixeira/little-book-of-semaphores-rust on toolchain f47dd4da3ae8c32c9e65d307bfe640b143e674df
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/cmhteixeira/little-book-of-semaphores-rust
[INFO] finished tweaking git repo https://github.com/cmhteixeira/little-book-of-semaphores-rust
[INFO] tweaked toml for git repo https://github.com/cmhteixeira/little-book-of-semaphores-rust written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate git repo https://github.com/cmhteixeira/little-book-of-semaphores-rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 247fd4c2de4f50a4e054f7e1ee6e8b8d76a68f4740e15f505a35cf918e21754f
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "247fd4c2de4f50a4e054f7e1ee6e8b8d76a68f4740e15f505a35cf918e21754f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "247fd4c2de4f50a4e054f7e1ee6e8b8d76a68f4740e15f505a35cf918e21754f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "247fd4c2de4f50a4e054f7e1ee6e8b8d76a68f4740e15f505a35cf918e21754f", kill_on_drop: false }`
[INFO] [stdout] 247fd4c2de4f50a4e054f7e1ee6e8b8d76a68f4740e15f505a35cf918e21754f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ec3cfa82fc8155471ecfbbe0f416c119b49e1bb535b6f30692d88f7619150271
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "ec3cfa82fc8155471ecfbbe0f416c119b49e1bb535b6f30692d88f7619150271", kill_on_drop: false }`
[INFO] [stderr]     Checking little-book-semaphores-rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::time::Duration`
[INFO] [stdout]  --> src/rendezvous.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::time::Duration;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Mutex`
[INFO] [stdout]  --> src/mutex.rs:2:22
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::sync::{Arc, Mutex};
[INFO] [stdout]   |                      ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `DerefMut`, `Deref`
[INFO] [stdout]  --> src/mutex.rs:5:16
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::ops::{DerefMut, Deref};
[INFO] [stdout]   |                ^^^^^^^^  ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `RefCell`
[INFO] [stdout]  --> src/mutex.rs:6:17
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::cell::{RefCell, UnsafeCell};
[INFO] [stdout]   |                 ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Duration`
[INFO] [stdout]  --> src/barrier.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::time::Duration;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `AtomicBool`
[INFO] [stdout]  --> src/barrier.rs:4:25
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::sync::atomic::{AtomicBool, Ordering};
[INFO] [stdout]   |                         ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::alloc::System`
[INFO] [stdout]  --> src/barrier.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::alloc::System;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::borrow::Borrow`
[INFO] [stdout]  --> src/queue.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::sync::Mutex`
[INFO] [stdout]  --> src/queue.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::sync::Mutex;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::ops::DerefMut`
[INFO] [stdout]  --> src/queue.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::ops::DerefMut;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Duration`
[INFO] [stdout]  --> src/rendezvous.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::time::Duration;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Mutex`
[INFO] [stdout]  --> src/mutex.rs:2:22
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::sync::{Arc, Mutex};
[INFO] [stdout]   |                      ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `DerefMut`, `Deref`
[INFO] [stdout]  --> src/mutex.rs:5:16
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::ops::{DerefMut, Deref};
[INFO] [stdout]   |                ^^^^^^^^  ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `RefCell`
[INFO] [stdout]  --> src/mutex.rs:6:17
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::cell::{RefCell, UnsafeCell};
[INFO] [stdout]   |                 ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Duration`
[INFO] [stdout]  --> src/barrier.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::time::Duration;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `AtomicBool`
[INFO] [stdout]  --> src/barrier.rs:4:25
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::sync::atomic::{AtomicBool, Ordering};
[INFO] [stdout]   |                         ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::alloc::System`
[INFO] [stdout]  --> src/barrier.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::alloc::System;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::borrow::Borrow`
[INFO] [stdout]  --> src/queue.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::sync::Mutex`
[INFO] [stdout]  --> src/queue.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::sync::Mutex;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::ops::DerefMut`
[INFO] [stdout]  --> src/queue.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::ops::DerefMut;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/mutex.rs:44:25
[INFO] [stdout]    |
[INFO] [stdout] 44 |                     let mut lock_obtained = arc.lock();
[INFO] [stdout]    |                         ----^^^^^^^^^^^^^
[INFO] [stdout]    |                         |
[INFO] [stdout]    |                         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: cannot borrow `*lock_obtained` as mutable because it is also borrowed as immutable
[INFO] [stdout]   --> src/mutex.rs:50:21
[INFO] [stdout]    |
[INFO] [stdout] 49 |                     let last = lock_obtained.last().unwrap_or(&0);
[INFO] [stdout]    |                                ------------- immutable borrow occurs here
[INFO] [stdout] 50 |                     lock_obtained.push(last.clone() + 1);
[INFO] [stdout]    |                     ^^^^^^^^^^^^^      ---- immutable borrow later used here
[INFO] [stdout]    |                     |
[INFO] [stdout]    |                     mutable borrow occurs here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(mutable_borrow_reservation_conflict)]` on by default
[INFO] [stdout]    = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stdout]    = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `das_multiplex`
[INFO] [stdout]  --> src/multiplex.rs:7:4
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn das_multiplex(n: u8, num_threads: u8) -> Vec<JoinHandle<()>>{
[INFO] [stdout]   |    ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/mutex.rs:44:25
[INFO] [stdout]    |
[INFO] [stdout] 44 |                     let mut lock_obtained = arc.lock();
[INFO] [stdout]    |                         ----^^^^^^^^^^^^^
[INFO] [stdout]    |                         |
[INFO] [stdout]    |                         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: cannot borrow `*lock_obtained` as mutable because it is also borrowed as immutable
[INFO] [stdout]   --> src/mutex.rs:50:21
[INFO] [stdout]    |
[INFO] [stdout] 49 |                     let last = lock_obtained.last().unwrap_or(&0);
[INFO] [stdout]    |                                ------------- immutable borrow occurs here
[INFO] [stdout] 50 |                     lock_obtained.push(last.clone() + 1);
[INFO] [stdout]    |                     ^^^^^^^^^^^^^      ---- immutable borrow later used here
[INFO] [stdout]    |                     |
[INFO] [stdout]    |                     mutable borrow occurs here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(mutable_borrow_reservation_conflict)]` on by default
[INFO] [stdout]    = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stdout]    = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `das_multiplex`
[INFO] [stdout]  --> src/multiplex.rs:7:4
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn das_multiplex(n: u8, num_threads: u8) -> Vec<JoinHandle<()>>{
[INFO] [stdout]   |    ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 13 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 13 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `little_book_semaphores_rust::Semaphore`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use little_book_semaphores_rust::Semaphore;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Duration`
[INFO] [stdout]  --> src/main.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::time::Duration;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `little_book_semaphores_rust::rendezvous::*`
[INFO] [stdout]  --> src/main.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use little_book_semaphores_rust::rendezvous::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `MyCustomMutex`, `monkey`
[INFO] [stdout]  --> src/main.rs:5:42
[INFO] [stdout]   |
[INFO] [stdout] 5 | use little_book_semaphores_rust::mutex::{monkey, MyCustomMutex};
[INFO] [stdout]   |                                          ^^^^^^  ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::ops::Deref`
[INFO] [stdout]  --> src/main.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::ops::Deref;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `little_book_semaphores_rust::barrier::barrier`
[INFO] [stdout]  --> src/main.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use little_book_semaphores_rust::barrier::barrier;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::thread::JoinHandle`
[INFO] [stdout]   --> src/main.rs:10:5
[INFO] [stdout]    |
[INFO] [stdout] 10 | use std::thread::JoinHandle;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/main.rs:27:8
[INFO] [stdout]    |
[INFO] [stdout] 27 |    for i in 1..10000 {
[INFO] [stdout]    |        ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `little_book_semaphores_rust::Semaphore`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use little_book_semaphores_rust::Semaphore;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Duration`
[INFO] [stdout]  --> src/main.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::time::Duration;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `little_book_semaphores_rust::rendezvous::*`
[INFO] [stdout]  --> src/main.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use little_book_semaphores_rust::rendezvous::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `MyCustomMutex`, `monkey`
[INFO] [stdout]  --> src/main.rs:5:42
[INFO] [stdout]   |
[INFO] [stdout] 5 | use little_book_semaphores_rust::mutex::{monkey, MyCustomMutex};
[INFO] [stdout]   |                                          ^^^^^^  ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::ops::Deref`
[INFO] [stdout]  --> src/main.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::ops::Deref;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `little_book_semaphores_rust::barrier::barrier`
[INFO] [stdout]  --> src/main.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use little_book_semaphores_rust::barrier::barrier;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::thread::JoinHandle`
[INFO] [stdout]   --> src/main.rs:10:5
[INFO] [stdout]    |
[INFO] [stdout] 10 | use std::thread::JoinHandle;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/main.rs:31:4
[INFO] [stdout]    |
[INFO] [stdout] 31 |    handle_a.join();
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/main.rs:27:8
[INFO] [stdout]    |
[INFO] [stdout] 27 |    for i in 1..10000 {
[INFO] [stdout]    |        ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 9 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/main.rs:31:4
[INFO] [stdout]    |
[INFO] [stdout] 31 |    handle_a.join();
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 9 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.25s
[INFO] running `Command { std: "docker" "inspect" "ec3cfa82fc8155471ecfbbe0f416c119b49e1bb535b6f30692d88f7619150271", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ec3cfa82fc8155471ecfbbe0f416c119b49e1bb535b6f30692d88f7619150271", kill_on_drop: false }`
[INFO] [stdout] ec3cfa82fc8155471ecfbbe0f416c119b49e1bb535b6f30692d88f7619150271