[INFO] cloning repository https://github.com/Razakhel/rs-ds
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Razakhel/rs-ds" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FRazakhel%2Frs-ds", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FRazakhel%2Frs-ds'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7fad62cad817e09dbf5244be8a21479d641ec05a
[INFO] checking Razakhel/rs-ds against master#a609fb45efad59dfd459c76e50899be9f0583b5a for pr-80579
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FRazakhel%2Frs-ds" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Razakhel/rs-ds on toolchain a609fb45efad59dfd459c76e50899be9f0583b5a
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Razakhel/rs-ds
[INFO] finished tweaking git repo https://github.com/Razakhel/rs-ds
[INFO] tweaked toml for git repo https://github.com/Razakhel/rs-ds written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/Razakhel/rs-ds already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3c49006fc1f9055501e37e7d41f258f064841aa16c03639c8f616da25e77d7e9
[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" "3c49006fc1f9055501e37e7d41f258f064841aa16c03639c8f616da25e77d7e9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3c49006fc1f9055501e37e7d41f258f064841aa16c03639c8f616da25e77d7e9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3c49006fc1f9055501e37e7d41f258f064841aa16c03639c8f616da25e77d7e9", kill_on_drop: false }`
[INFO] [stdout] 3c49006fc1f9055501e37e7d41f258f064841aa16c03639c8f616da25e77d7e9
[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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d6350833b8a8814067735dfc8e2a8fd3a6eb667abc12fcca91c9562c3356dad7
[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" "d6350833b8a8814067735dfc8e2a8fd3a6eb667abc12fcca91c9562c3356dad7", kill_on_drop: false }`
[INFO] [stderr]     Checking rs-ds v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: associated function is never used: `peek`
[INFO] [stdout]   --> src/linked_list.rs:38:10
[INFO] [stdout]    |
[INFO] [stdout] 38 |   pub fn peek(&self) -> Option<&T> {
[INFO] [stdout]    |          ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `peek_mut`
[INFO] [stdout]   --> src/linked_list.rs:44:10
[INFO] [stdout]    |
[INFO] [stdout] 44 |   pub fn peek_mut(&mut self) -> Option<&mut T> {
[INFO] [stdout]    |          ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `into_iter`
[INFO] [stdout]   --> src/linked_list.rs:50:10
[INFO] [stdout]    |
[INFO] [stdout] 50 |   pub fn into_iter(self) -> IntoIter<T> {
[INFO] [stdout]    |          ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.77s
[INFO] running `Command { std: "docker" "inspect" "d6350833b8a8814067735dfc8e2a8fd3a6eb667abc12fcca91c9562c3356dad7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d6350833b8a8814067735dfc8e2a8fd3a6eb667abc12fcca91c9562c3356dad7", kill_on_drop: false }`
[INFO] [stdout] d6350833b8a8814067735dfc8e2a8fd3a6eb667abc12fcca91c9562c3356dad7