[INFO] cloning repository https://github.com/michealkeines/TCP-Messenger
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/michealkeines/TCP-Messenger" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmichealkeines%2FTCP-Messenger", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmichealkeines%2FTCP-Messenger'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] c8e8304cda05e0e016056e43dd0544a2cfcaab66
[INFO] checking michealkeines/TCP-Messenger against try#54cf65b8d066c082e536455049b95943cf30378f for pr-151920
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmichealkeines%2FTCP-Messenger" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/michealkeines/TCP-Messenger
[INFO] finished tweaking git repo https://github.com/michealkeines/TCP-Messenger
[INFO] tweaked toml for git repo https://github.com/michealkeines/TCP-Messenger written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/michealkeines/TCP-Messenger on toolchain 54cf65b8d066c082e536455049b95943cf30378f
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+54cf65b8d066c082e536455049b95943cf30378f" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/michealkeines/TCP-Messenger already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+54cf65b8d066c082e536455049b95943cf30378f" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded clap_lex v0.2.0
[INFO] [stderr]   Downloaded indexmap v1.8.2
[INFO] [stderr]   Downloaded clap v3.1.18
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:61361fe0aef631f17e9d025a70c5a647956f8c671dd02950a60ad3f5cc5526d7" "/opt/rustwide/cargo-home/bin/cargo" "+54cf65b8d066c082e536455049b95943cf30378f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 02b0689a847099da1bee667cdf0f10aac6d3823b928310fb10cfa920467bc525
[INFO] running `Command { std: "docker" "start" "-a" "02b0689a847099da1bee667cdf0f10aac6d3823b928310fb10cfa920467bc525", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "02b0689a847099da1bee667cdf0f10aac6d3823b928310fb10cfa920467bc525", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "02b0689a847099da1bee667cdf0f10aac6d3823b928310fb10cfa920467bc525", kill_on_drop: false }`
[INFO] [stdout] 02b0689a847099da1bee667cdf0f10aac6d3823b928310fb10cfa920467bc525
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:61361fe0aef631f17e9d025a70c5a647956f8c671dd02950a60ad3f5cc5526d7" "/opt/rustwide/cargo-home/bin/cargo" "+54cf65b8d066c082e536455049b95943cf30378f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] dbfbef1bc41f51546464635caad7c29fb22c24567b503a19bb17bbc479667582
[INFO] running `Command { std: "docker" "start" "-a" "dbfbef1bc41f51546464635caad7c29fb22c24567b503a19bb17bbc479667582", kill_on_drop: false }`
[INFO] [stderr]    Compiling memoffset v0.5.6
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]    Compiling indexmap v1.8.2
[INFO] [stderr]     Checking hashbrown v0.11.2
[INFO] [stderr]     Checking clap_lex v0.2.0
[INFO] [stderr]     Checking crossbeam-channel v0.4.4
[INFO] [stderr]     Checking crossbeam-queue v0.2.3
[INFO] [stderr]     Checking crossbeam-deque v0.7.4
[INFO] [stderr]     Checking crossbeam v0.7.3
[INFO] [stderr]     Checking clap v3.1.18
[INFO] [stderr]     Checking messenger v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused imports: `Ipv4Addr`, `Shutdown`, `SocketAddrV4`, `SocketAddr`, and `TcpStream`
[INFO] [stdout]  --> src/network.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 |     TcpStream,
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout] 4 |     Ipv4Addr,
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 5 |     SocketAddr,
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout] 6 |     SocketAddrV4,
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout] 7 |     Shutdown
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Ipv4Addr`, `Shutdown`, `SocketAddrV4`, `SocketAddr`, and `TcpStream`
[INFO] [stdout]  --> src/server.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 |     TcpStream,
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout] 4 |     Ipv4Addr,
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 5 |     SocketAddr,
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout] 6 |     SocketAddrV4,
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout] 7 |     Shutdown
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Read`, `Write`, and `self`
[INFO] [stdout]   --> src/server.rs:10:16
[INFO] [stdout]    |
[INFO] [stdout] 10 | use std::io::{ self, Read, Write };
[INFO] [stdout]    |                ^^^^  ^^^^  ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cell::RefCell`
[INFO] [stdout]   --> src/server.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 | use std::cell::RefCell;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::fs::File`
[INFO] [stdout]   --> src/server.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 | use std::fs::File;
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::marker::Sized`
[INFO] [stdout]   --> src/server.rs:17:5
[INFO] [stdout]    |
[INFO] [stdout] 17 | use std::marker::Sized;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::server`
[INFO] [stdout]   --> src/server.rs:19:5
[INFO] [stdout]    |
[INFO] [stdout] 19 | use crate::server;
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Instant`
[INFO] [stdout]  --> src/receiver.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::time::Instant;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Instant`
[INFO] [stdout]  --> src/sender.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::time::Instant;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Ipv4Addr`, `Shutdown`, `SocketAddrV4`, `SocketAddr`, and `TcpStream`
[INFO] [stdout]  --> src/network.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 |     TcpStream,
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout] 4 |     Ipv4Addr,
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 5 |     SocketAddr,
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout] 6 |     SocketAddrV4,
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout] 7 |     Shutdown
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Ipv4Addr`, `Shutdown`, `SocketAddrV4`, `SocketAddr`, and `TcpStream`
[INFO] [stdout]  --> src/server.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 |     TcpStream,
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout] 4 |     Ipv4Addr,
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 5 |     SocketAddr,
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout] 6 |     SocketAddrV4,
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout] 7 |     Shutdown
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Read`, `Write`, and `self`
[INFO] [stdout]   --> src/server.rs:10:16
[INFO] [stdout]    |
[INFO] [stdout] 10 | use std::io::{ self, Read, Write };
[INFO] [stdout]    |                ^^^^  ^^^^  ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cell::RefCell`
[INFO] [stdout]   --> src/server.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 | use std::cell::RefCell;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::fs::File`
[INFO] [stdout]   --> src/server.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 | use std::fs::File;
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::marker::Sized`
[INFO] [stdout]   --> src/server.rs:17:5
[INFO] [stdout]    |
[INFO] [stdout] 17 | use std::marker::Sized;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::server`
[INFO] [stdout]   --> src/server.rs:19:5
[INFO] [stdout]    |
[INFO] [stdout] 19 | use crate::server;
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/server.rs:52:29
[INFO] [stdout]    |
[INFO] [stdout] 52 |                         let c = temp.clone();
[INFO] [stdout]    |                             ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/server.rs:52:29
[INFO] [stdout]    |
[INFO] [stdout] 52 |                         let c = temp.clone();
[INFO] [stdout]    |                             ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `data` is never read
[INFO] [stdout]  --> src/receiver.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub struct ReceiveMessage<T> {
[INFO] [stdout]   |            -------------- field in this struct
[INFO] [stdout] 5 |     data: Message<T>
[INFO] [stdout]   |     ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `data` is never read
[INFO] [stdout]  --> src/sender.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub struct SendMessage<T> {
[INFO] [stdout]   |            ----------- field in this struct
[INFO] [stdout] 5 |     data: Message<T>
[INFO] [stdout]   |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/client.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |         stream.set_read_timeout(Some(std::time::Duration::from_millis(300)));
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 19 |         let _ = stream.set_read_timeout(Some(std::time::Duration::from_millis(300)));
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/user.rs:83:9
[INFO] [stdout]    |
[INFO] [stdout] 83 |         lock.write(&msg);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 83 |         let _ = lock.write(&msg);
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/user.rs:96:13
[INFO] [stdout]    |
[INFO] [stdout] 96 |             lock_stream.set_read_timeout(Some(time::Duration::from_millis(150)));
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 96 |             let _ = lock_stream.set_read_timeout(Some(time::Duration::from_millis(150)));
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/user.rs:97:13
[INFO] [stdout]    |
[INFO] [stdout] 97 |             lock_stream.read_exact(&mut temp[..]);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 97 |             let _ = lock_stream.read_exact(&mut temp[..]);
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/client.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |         stream.set_read_timeout(Some(std::time::Duration::from_millis(300)));
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 19 |         let _ = stream.set_read_timeout(Some(std::time::Duration::from_millis(300)));
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/user.rs:83:9
[INFO] [stdout]    |
[INFO] [stdout] 83 |         lock.write(&msg);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 83 |         let _ = lock.write(&msg);
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/user.rs:96:13
[INFO] [stdout]    |
[INFO] [stdout] 96 |             lock_stream.set_read_timeout(Some(time::Duration::from_millis(150)));
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 96 |             let _ = lock_stream.set_read_timeout(Some(time::Duration::from_millis(150)));
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/user.rs:97:13
[INFO] [stdout]    |
[INFO] [stdout] 97 |             lock_stream.read_exact(&mut temp[..]);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 97 |             let _ = lock_stream.read_exact(&mut temp[..]);
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::stdin`
[INFO] [stdout]  --> src/main.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::io::stdin;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::stdin`
[INFO] [stdout]  --> src/main.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::io::stdin;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/main.rs:45:25
[INFO] [stdout]    |
[INFO] [stdout] 45 |                     let v = std::io::stdin().read_line(&mut line).unwrap();
[INFO] [stdout]    |                         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/main.rs:45:25
[INFO] [stdout]    |
[INFO] [stdout] 45 |                     let v = std::io::stdin().read_line(&mut line).unwrap();
[INFO] [stdout]    |                         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 3.97s
[INFO] running `Command { std: "docker" "inspect" "dbfbef1bc41f51546464635caad7c29fb22c24567b503a19bb17bbc479667582", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dbfbef1bc41f51546464635caad7c29fb22c24567b503a19bb17bbc479667582", kill_on_drop: false }`
[INFO] [stdout] dbfbef1bc41f51546464635caad7c29fb22c24567b503a19bb17bbc479667582
