[INFO] cloning repository https://github.com/alexxuyang/tokio-examples
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/alexxuyang/tokio-examples" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falexxuyang%2Ftokio-examples", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falexxuyang%2Ftokio-examples'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 38774c6c9eea4dbdc17b6877adb17fa7278e3405
[INFO] testing alexxuyang/tokio-examples against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falexxuyang%2Ftokio-examples" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/alexxuyang/tokio-examples 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/alexxuyang/tokio-examples
[INFO] finished tweaking git repo https://github.com/alexxuyang/tokio-examples
[INFO] tweaked toml for git repo https://github.com/alexxuyang/tokio-examples written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/alexxuyang/tokio-examples 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-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] 1c494285817245ed6007ed63730d4b959ad194efca94f598a7bc9d013c09e0f0
[INFO] running `Command { std: "docker" "start" "-a" "1c494285817245ed6007ed63730d4b959ad194efca94f598a7bc9d013c09e0f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1c494285817245ed6007ed63730d4b959ad194efca94f598a7bc9d013c09e0f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1c494285817245ed6007ed63730d4b959ad194efca94f598a7bc9d013c09e0f0", kill_on_drop: false }`
[INFO] [stdout] 1c494285817245ed6007ed63730d4b959ad194efca94f598a7bc9d013c09e0f0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] [stdout] 975e9d104200be4942f3d0d20550381eb6d04f5dbfa6262fb19d5d8f5b81cc39
[INFO] running `Command { std: "docker" "start" "-a" "975e9d104200be4942f3d0d20550381eb6d04f5dbfa6262fb19d5d8f5b81cc39", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.54
[INFO] [stderr]    Compiling autocfg v0.1.2
[INFO] [stderr]    Compiling futures v0.1.26
[INFO] [stderr]    Compiling stable_deref_trait v1.1.1
[INFO] [stderr]    Compiling arrayvec v0.4.10
[INFO] [stderr]    Compiling nodrop v0.1.13
[INFO] [stderr]    Compiling crossbeam-utils v0.6.5
[INFO] [stderr]    Compiling tokio-trace-core v0.1.0
[INFO] [stderr]    Compiling parking_lot_core v0.4.0
[INFO] [stderr]    Compiling owning_ref v0.4.0
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling lock_api v0.1.5
[INFO] [stderr]    Compiling crossbeam-queue v0.1.2
[INFO] [stderr]    Compiling crossbeam-epoch v0.7.1
[INFO] [stderr]    Compiling iovec v0.1.2
[INFO] [stderr]    Compiling rand_os v0.1.3
[INFO] [stderr]    Compiling num_cpus v1.10.0
[INFO] [stderr]    Compiling net2 v0.2.33
[INFO] [stderr]    Compiling bytes v0.4.12
[INFO] [stderr]    Compiling crossbeam-deque v0.7.1
[INFO] [stderr]    Compiling tokio-executor v0.1.7
[INFO] [stderr]    Compiling tokio-sync v0.1.5
[INFO] [stderr]    Compiling mio v0.6.16
[INFO] [stderr]    Compiling tokio-current-thread v0.1.6
[INFO] [stderr]    Compiling tokio-timer v0.2.10
[INFO] [stderr]    Compiling tokio-io v0.1.12
[INFO] [stderr]    Compiling mio-uds v0.6.7
[INFO] [stderr]    Compiling tokio-codec v0.1.1
[INFO] [stderr]    Compiling tokio-threadpool v0.1.14
[INFO] [stderr]    Compiling parking_lot v0.7.1
[INFO] [stderr]    Compiling tokio-reactor v0.1.9
[INFO] [stderr]    Compiling tokio-fs v0.1.6
[INFO] [stderr]    Compiling tokio-tcp v0.1.3
[INFO] [stderr]    Compiling tokio-uds v0.2.5
[INFO] [stderr]    Compiling tokio-udp v0.1.3
[INFO] [stderr]    Compiling tokio v0.1.19
[INFO] [stderr]    Compiling tokio-examples v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.57s
[INFO] running `Command { std: "docker" "inspect" "975e9d104200be4942f3d0d20550381eb6d04f5dbfa6262fb19d5d8f5b81cc39", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "975e9d104200be4942f3d0d20550381eb6d04f5dbfa6262fb19d5d8f5b81cc39", kill_on_drop: false }`
[INFO] [stdout] 975e9d104200be4942f3d0d20550381eb6d04f5dbfa6262fb19d5d8f5b81cc39
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] 2a1a99db39bb66f5af047a57cd620f240168a953e62735cc279995092a21487c
[INFO] running `Command { std: "docker" "start" "-a" "2a1a99db39bb66f5af047a57cd620f240168a953e62735cc279995092a21487c", kill_on_drop: false }`
[INFO] [stderr]    Compiling tokio-examples v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::error::Error`
[INFO] [stdout]  --> examples/select.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 | use std::error::Error;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `futures::future`
[INFO] [stdout]  --> examples/stream2.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use futures::future;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `futures::Future`
[INFO] [stdout]  --> examples/stream2.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use futures::Future;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> examples/then.rs:9:37
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn simple_func() -> Result<u32, Box<Error>> {
[INFO] [stdout]   |                                     ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]   = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `#[macro_use]` import
[INFO] [stdout]  --> examples/peeraddr.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #[macro_use]
[INFO] [stdout]   | ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `futures::future`
[INFO] [stdout]  --> examples/peeraddr.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use futures::future;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> examples/andthen1.rs:7:37
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn simple_func() -> Result<u32, Box<Error>> {
[INFO] [stdout]   |                                     ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]   = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `futures::future`
[INFO] [stdout]  --> examples/stream.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use futures::future;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> examples/fold.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let mut dst = vec![];
[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 `#[macro_use]` import
[INFO] [stdout]  --> examples/lazy2.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #[macro_use]
[INFO] [stdout]   | ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `tokio::timer::Delay`
[INFO] [stdout]  --> examples/lazy2.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use tokio::timer::Delay;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Duration`, `Instant`
[INFO] [stdout]  --> examples/lazy2.rs:9:17
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::time::{Duration, Instant};
[INFO] [stdout]   |                 ^^^^^^^^  ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::ops::Add`
[INFO] [stdout]   --> examples/lazy2.rs:10:5
[INFO] [stdout]    |
[INFO] [stdout] 10 | use std::ops::Add;
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `futures::Stream`
[INFO] [stdout]  --> examples/lazy2.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use futures::Stream;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `futures::future`
[INFO] [stdout]  --> examples/map.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use futures::future;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::fmt`
[INFO] [stdout]  --> examples/map.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::fmt;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around function argument
[INFO] [stdout]   --> examples/map.rs:16:25
[INFO] [stdout]    |
[INFO] [stdout] 16 |         Ok(Async::Ready((String::from("hello world!"))))
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `futures::future`
[INFO] [stdout]  --> examples/timeout.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use futures::future;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `futures::future`
[INFO] [stdout]  --> examples/andthen2.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use futures::future;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `future`
[INFO] [stdout]  --> examples/writebuf.rs:6:23
[INFO] [stdout]   |
[INFO] [stdout] 6 | use futures::{Future, future};
[INFO] [stdout]   |                       ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `futures::future`
[INFO] [stdout]  --> examples/tryready1.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use futures::future;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around function argument
[INFO] [stdout]   --> examples/tryready1.rs:16:25
[INFO] [stdout]    |
[INFO] [stdout] 16 |         Ok(Async::Ready((String::from("hello world!"))))
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `tokio::prelude`
[INFO] [stdout]  --> examples/andthen2.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use tokio::prelude::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> examples/writebuf.rs:34:25
[INFO] [stdout]    |
[INFO] [stdout] 34 |                         socket.write_buf(data);
[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 import: `futures::future`
[INFO] [stdout]  --> examples/tryready2.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use futures::future;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around function argument
[INFO] [stdout]   --> examples/tryready2.rs:17:25
[INFO] [stdout]    |
[INFO] [stdout] 17 |         Ok(Async::Ready((String::from("hello world!"))))
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `futures::future`
[INFO] [stdout]  --> examples/andthen3.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use futures::future;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `futures::future`
[INFO] [stdout]  --> examples/delay.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use futures::future;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `tokio::prelude`
[INFO] [stdout]  --> examples/delay.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use tokio::prelude::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `tokio::prelude`
[INFO] [stdout]  --> examples/andthen3.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use tokio::prelude::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `socket`
[INFO] [stdout]   --> examples/andthen3.rs:22:21
[INFO] [stdout]    |
[INFO] [stdout] 22 |         .and_then(|(socket, buf)| {
[INFO] [stdout]    |                     ^^^^^^ help: if this is intentional, prefix it with an underscore: `_socket`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `tokio-examples`; 3 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustc --crate-name andthen3 --edition=2018 examples/andthen3.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type bin --emit=dep-info,link -C embed-bitcode=no -C debuginfo=2 -C metadata=73b0aba1efd701fb -C extra-filename=-73b0aba1efd701fb --out-dir /opt/rustwide/target/debug/examples -L dependency=/opt/rustwide/target/debug/deps --extern bytes=/opt/rustwide/target/debug/deps/libbytes-589921b6d4e37112.rlib --extern futures=/opt/rustwide/target/debug/deps/libfutures-d83d07a6ba5763dc.rlib --extern tokio=/opt/rustwide/target/debug/deps/libtokio-dd628459cac32a02.rlib --cap-lints=warn` (signal: 9, SIGKILL: kill)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "2a1a99db39bb66f5af047a57cd620f240168a953e62735cc279995092a21487c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2a1a99db39bb66f5af047a57cd620f240168a953e62735cc279995092a21487c", kill_on_drop: false }`
[INFO] [stdout] 2a1a99db39bb66f5af047a57cd620f240168a953e62735cc279995092a21487c