[INFO] cloning repository https://github.com/MaxLuchs/channel_ping_pong
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/MaxLuchs/channel_ping_pong" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMaxLuchs%2Fchannel_ping_pong", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMaxLuchs%2Fchannel_ping_pong'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 1a8e4ce15f0188a04322241eb5273e6436deeb18
[INFO] testing MaxLuchs/channel_ping_pong against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMaxLuchs%2Fchannel_ping_pong" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/MaxLuchs/channel_ping_pong on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/MaxLuchs/channel_ping_pong
[INFO] finished tweaking git repo https://github.com/MaxLuchs/channel_ping_pong
[INFO] tweaked toml for git repo https://github.com/MaxLuchs/channel_ping_pong written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/MaxLuchs/channel_ping_pong already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 62705e7511a49884b03d27da6f9ee442c3b88877e4aac4c7e8eeb3165efd5bcd
[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" "62705e7511a49884b03d27da6f9ee442c3b88877e4aac4c7e8eeb3165efd5bcd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "62705e7511a49884b03d27da6f9ee442c3b88877e4aac4c7e8eeb3165efd5bcd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "62705e7511a49884b03d27da6f9ee442c3b88877e4aac4c7e8eeb3165efd5bcd", kill_on_drop: false }`
[INFO] [stdout] 62705e7511a49884b03d27da6f9ee442c3b88877e4aac4c7e8eeb3165efd5bcd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 4f840a1cef9155f7c7346b7817009e957e8c9405bf212064a16f7b157cf5ee37
[INFO] running `Command { std: "docker" "start" "-a" "4f840a1cef9155f7c7346b7817009e957e8c9405bf212064a16f7b157cf5ee37", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.64
[INFO] [stderr]    Compiling crossbeam-utils v0.8.3
[INFO] [stderr]    Compiling tokio v1.3.0
[INFO] [stderr]    Compiling mio v0.7.9
[INFO] [stderr]    Compiling signal-hook v0.1.17
[INFO] [stderr]    Compiling crossterm v0.19.0
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.3
[INFO] [stderr]    Compiling crossbeam-channel v0.5.0
[INFO] [stderr]    Compiling crossbeam-queue v0.3.1
[INFO] [stderr]    Compiling crossbeam-deque v0.8.0
[INFO] [stderr]    Compiling crossbeam v0.8.0
[INFO] [stderr]    Compiling tokio-macros v1.1.0
[INFO] [stderr]    Compiling thread_pong v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/thread.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let mut stdin = stdin();
[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: unused `Result` that must be used
[INFO] [stdout]   --> src/thread.rs:21:17
[INFO] [stdout]    |
[INFO] [stdout] 21 |                 s2.send(Some(Message { idx: msg.idx + 1, text: "pong" }));
[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 `Result` that must be used
[INFO] [stdout]   --> src/thread.rs:31:17
[INFO] [stdout]    |
[INFO] [stdout] 31 |                 s1_clone.send(Some(Message { idx: msg.idx + 1, text: "ping" }));
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/thread.rs:36:5
[INFO] [stdout]    |
[INFO] [stdout] 36 |     s1.send(Some(Message { idx: 0, text: "ping" }));
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/thread.rs:42:9
[INFO] [stdout]    |
[INFO] [stdout] 42 |         stdin.read_line(&mut input);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/thread.rs:45:13
[INFO] [stdout]    |
[INFO] [stdout] 45 |             s1.send(None);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/thread.rs:46:13
[INFO] [stdout]    |
[INFO] [stdout] 46 |             s2_clone.send(None);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/thread.rs:50:57
[INFO] [stdout]    |
[INFO] [stdout] 50 |     vec![handle_1, handle_2].into_iter().for_each(|h| { h.join(); });
[INFO] [stdout]    |                                                         ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 8 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 38.27s
[INFO] running `Command { std: "docker" "inspect" "4f840a1cef9155f7c7346b7817009e957e8c9405bf212064a16f7b157cf5ee37", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4f840a1cef9155f7c7346b7817009e957e8c9405bf212064a16f7b157cf5ee37", kill_on_drop: false }`
[INFO] [stdout] 4f840a1cef9155f7c7346b7817009e957e8c9405bf212064a16f7b157cf5ee37
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a281f113841b63c035edf792638f9a3aa700037ae2e22c7b19ce446578aacfa8
[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" "a281f113841b63c035edf792638f9a3aa700037ae2e22c7b19ce446578aacfa8", kill_on_drop: false }`
[INFO] [stderr]    Compiling thread_pong v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/thread.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let mut stdin = stdin();
[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: unused `Result` that must be used
[INFO] [stdout]   --> src/thread.rs:21:17
[INFO] [stdout]    |
[INFO] [stdout] 21 |                 s2.send(Some(Message { idx: msg.idx + 1, text: "pong" }));
[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 `Result` that must be used
[INFO] [stdout]   --> src/thread.rs:31:17
[INFO] [stdout]    |
[INFO] [stdout] 31 |                 s1_clone.send(Some(Message { idx: msg.idx + 1, text: "ping" }));
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/thread.rs:36:5
[INFO] [stdout]    |
[INFO] [stdout] 36 |     s1.send(Some(Message { idx: 0, text: "ping" }));
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/thread.rs:42:9
[INFO] [stdout]    |
[INFO] [stdout] 42 |         stdin.read_line(&mut input);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/thread.rs:45:13
[INFO] [stdout]    |
[INFO] [stdout] 45 |             s1.send(None);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/thread.rs:46:13
[INFO] [stdout]    |
[INFO] [stdout] 46 |             s2_clone.send(None);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/thread.rs:50:57
[INFO] [stdout]    |
[INFO] [stdout] 50 |     vec![handle_1, handle_2].into_iter().for_each(|h| { h.join(); });
[INFO] [stdout]    |                                                         ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 8 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 1.47s
[INFO] running `Command { std: "docker" "inspect" "a281f113841b63c035edf792638f9a3aa700037ae2e22c7b19ce446578aacfa8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a281f113841b63c035edf792638f9a3aa700037ae2e22c7b19ce446578aacfa8", kill_on_drop: false }`
[INFO] [stdout] a281f113841b63c035edf792638f9a3aa700037ae2e22c7b19ce446578aacfa8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 4e087e0d47f6cc97e1015c5fd3f6644a747216793f554f9e6c3039372e1d8d67
[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" "4e087e0d47f6cc97e1015c5fd3f6644a747216793f554f9e6c3039372e1d8d67", kill_on_drop: false }`
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/thread.rs:38:9
[INFO] [stderr]    |
[INFO] [stderr] 38 |     let mut stdin = stdin();
[INFO] [stderr]    |         ----^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/thread.rs:21:17
[INFO] [stderr]    |
[INFO] [stderr] 21 |                 s2.send(Some(Message { idx: msg.idx + 1, text: "pong" }));
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/thread.rs:31:17
[INFO] [stderr]    |
[INFO] [stderr] 31 |                 s1_clone.send(Some(Message { idx: msg.idx + 1, text: "ping" }));
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/thread.rs:36:5
[INFO] [stderr]    |
[INFO] [stderr] 36 |     s1.send(Some(Message { idx: 0, text: "ping" }));
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/thread.rs:42:9
[INFO] [stderr]    |
[INFO] [stderr] 42 |         stdin.read_line(&mut input);
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/thread.rs:45:13
[INFO] [stderr]    |
[INFO] [stderr] 45 |             s1.send(None);
[INFO] [stderr]    |             ^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/thread.rs:46:13
[INFO] [stderr]    |
[INFO] [stderr] 46 |             s2_clone.send(None);
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/thread.rs:50:57
[INFO] [stderr]    |
[INFO] [stderr] 50 |     vec![handle_1, handle_2].into_iter().for_each(|h| { h.join(); });
[INFO] [stderr]    |                                                         ^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: `thread_pong` (bin "thread" test) generated 8 warnings
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.05s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/green-13f1183540e01143)
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/thread-d1b8ede297f0bd5d)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "4e087e0d47f6cc97e1015c5fd3f6644a747216793f554f9e6c3039372e1d8d67", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4e087e0d47f6cc97e1015c5fd3f6644a747216793f554f9e6c3039372e1d8d67", kill_on_drop: false }`
[INFO] [stdout] 4e087e0d47f6cc97e1015c5fd3f6644a747216793f554f9e6c3039372e1d8d67