[INFO] fetching crate wm8731 0.1.0...
[INFO] checking wm8731-0.1.0 against try#6f8a6450478f69b8510c8976ab6c2a70b3b0e47c for pr-84920
[INFO] extracting crate wm8731 0.1.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate wm8731 0.1.0 on toolchain 6f8a6450478f69b8510c8976ab6c2a70b3b0e47c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate wm8731 0.1.0
[INFO] finished tweaking crates.io crate wm8731 0.1.0
[INFO] tweaked toml for crates.io crate wm8731 0.1.0 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] acde0c4c633ddb31a7a9209e4a90b620453b81173b048ad47aac3fd09ad2dc32
[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" "acde0c4c633ddb31a7a9209e4a90b620453b81173b048ad47aac3fd09ad2dc32", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "acde0c4c633ddb31a7a9209e4a90b620453b81173b048ad47aac3fd09ad2dc32", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "acde0c4c633ddb31a7a9209e4a90b620453b81173b048ad47aac3fd09ad2dc32", kill_on_drop: false }`
[INFO] [stdout] acde0c4c633ddb31a7a9209e4a90b620453b81173b048ad47aac3fd09ad2dc32
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f39f3cb23665b5dffd4f615b18399d99ae0234581e6c45912f916d6db874e72a
[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" "f39f3cb23665b5dffd4f615b18399d99ae0234581e6c45912f916d6db874e72a", kill_on_drop: false }`
[INFO] [stderr]     Checking wm8731 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `volume`
[INFO] [stdout]   --> src/headphone_out.rs:24:30
[INFO] [stdout]    |
[INFO] [stdout] 24 |     pub fn volume(&mut self, volume: u16) {
[INFO] [stdout]    |                              ^^^^^^ help: if this is intentional, prefix it with an underscore: `_volume`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `volume`
[INFO] [stdout]   --> src/headphone_out.rs:24:30
[INFO] [stdout]    |
[INFO] [stdout] 24 |     pub fn volume(&mut self, volume: u16) {
[INFO] [stdout]    |                              ^^^^^^ help: if this is intentional, prefix it with an underscore: `_volume`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.58s
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "f39f3cb23665b5dffd4f615b18399d99ae0234581e6c45912f916d6db874e72a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f39f3cb23665b5dffd4f615b18399d99ae0234581e6c45912f916d6db874e72a", kill_on_drop: false }`
[INFO] [stdout] f39f3cb23665b5dffd4f615b18399d99ae0234581e6c45912f916d6db874e72a