[INFO] cloning repository https://github.com/sabahtalateh/rust-async-book
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/sabahtalateh/rust-async-book" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsabahtalateh%2Frust-async-book", kill_on_drop: false }`
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[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 1f1be3396332455f288719bd2f163fba11b7f47d
[INFO] checking sabahtalateh/rust-async-book against master#bca37a20bd376ce3fd138e7cdee7fe704e0f8814 for pr-139493-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsabahtalateh%2Frust-async-book" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
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[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/sabahtalateh/rust-async-book
[INFO] finished tweaking git repo https://github.com/sabahtalateh/rust-async-book
[INFO] tweaked toml for git repo https://github.com/sabahtalateh/rust-async-book written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/sabahtalateh/rust-async-book on toolchain bca37a20bd376ce3fd138e7cdee7fe704e0f8814
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+bca37a20bd376ce3fd138e7cdee7fe704e0f8814" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/sabahtalateh/rust-async-book 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" "+bca37a20bd376ce3fd138e7cdee7fe704e0f8814" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
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[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/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:aa71247004a7fa38d13ec170f48f06cdedf5bc50b2a8645e56ed7e992e6fa513" "/opt/rustwide/cargo-home/bin/cargo" "+bca37a20bd376ce3fd138e7cdee7fe704e0f8814" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
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[INFO] running `Command { std: "docker" "start" "-a" "71971642ca35b4032818ed7084634a517fef8476bcdfa31a1f128585a3e7c555", kill_on_drop: false }`
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[INFO] [stdout] warning: unused import: `std::process::Output`
[INFO] [stdout]  --> src/bin/executor.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::process::Output;
[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::process::Output`
[INFO] [stdout]  --> src/bin/executor.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::process::Output;
[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: `a`
[INFO] [stdout]   --> src/bin/pin.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let a = "1".as_bytes().to_vec();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/event_loop.rs:52:20
[INFO] [stdout]    |
[INFO] [stdout] 52 |                 Ok(mut t) => {
[INFO] [stdout]    |                    ----^
[INFO] [stdout]    |                    |
[INFO] [stdout]    |                    help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/event_loop.rs:52:20
[INFO] [stdout]    |
[INFO] [stdout] 52 |                 Ok(mut t) => {
[INFO] [stdout]    |                    ----^
[INFO] [stdout]    |                    |
[INFO] [stdout]    |                    help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/bin/pin.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let a = "1".as_bytes().to_vec();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/event_loop.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |         self.tasks_sender.send(task);
[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] 38 |         let _ = self.tasks_sender.send(task);
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/event_loop.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |         self.tasks_sender.send(task);
[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] 38 |         let _ = self.tasks_sender.send(task);
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 10.86s
[INFO] running `Command { std: "docker" "inspect" "71971642ca35b4032818ed7084634a517fef8476bcdfa31a1f128585a3e7c555", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "71971642ca35b4032818ed7084634a517fef8476bcdfa31a1f128585a3e7c555", kill_on_drop: false }`
[INFO] [stdout] 71971642ca35b4032818ed7084634a517fef8476bcdfa31a1f128585a3e7c555