[INFO] cloning repository https://github.com/scrogson/linked-list-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/scrogson/linked-list-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fscrogson%2Flinked-list-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fscrogson%2Flinked-list-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f4a8134bc9afc1068719ca9e77705406fbb2f8fc
[INFO] checking scrogson/linked-list-rs against master#3aedcf06b73fc36feeebca3d579e1d2a6c40acc5 for pr-65819
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fscrogson%2Flinked-list-rs" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/scrogson/linked-list-rs on toolchain 3aedcf06b73fc36feeebca3d579e1d2a6c40acc5
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3aedcf06b73fc36feeebca3d579e1d2a6c40acc5" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/scrogson/linked-list-rs
[INFO] finished tweaking git repo https://github.com/scrogson/linked-list-rs
[INFO] tweaked toml for git repo https://github.com/scrogson/linked-list-rs written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/scrogson/linked-list-rs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3aedcf06b73fc36feeebca3d579e1d2a6c40acc5" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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:c46a2d1a26fb48b37929c74ca49dd9409f2375a0a3bdb8fe07617f3ffccaa889" "/opt/rustwide/cargo-home/bin/cargo" "+3aedcf06b73fc36feeebca3d579e1d2a6c40acc5" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d4515e088d4a2ff66a4d83ee8d0f8fb9f9d10fb9d22dbac189b53200f4ade2f4
[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" "d4515e088d4a2ff66a4d83ee8d0f8fb9f9d10fb9d22dbac189b53200f4ade2f4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d4515e088d4a2ff66a4d83ee8d0f8fb9f9d10fb9d22dbac189b53200f4ade2f4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d4515e088d4a2ff66a4d83ee8d0f8fb9f9d10fb9d22dbac189b53200f4ade2f4", kill_on_drop: false }`
[INFO] [stdout] d4515e088d4a2ff66a4d83ee8d0f8fb9f9d10fb9d22dbac189b53200f4ade2f4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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:c46a2d1a26fb48b37929c74ca49dd9409f2375a0a3bdb8fe07617f3ffccaa889" "/opt/rustwide/cargo-home/bin/cargo" "+3aedcf06b73fc36feeebca3d579e1d2a6c40acc5" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d7ffab0656d286b1544537a0ad86cef751058aa67ebd4d3b489dfa1b882ae371
[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" "d7ffab0656d286b1544537a0ad86cef751058aa67ebd4d3b489dfa1b882ae371", kill_on_drop: false }`
[INFO] [stderr]     Checking linked-list-rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field is never read: `tail`
[INFO] [stdout]  --> src/fourth.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     tail: Link<T>,
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `elem`
[INFO] [stdout]   --> src/fourth.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     elem: T,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `next`
[INFO] [stdout]   --> src/fourth.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     next: Link<T>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `prev`
[INFO] [stdout]   --> src/fourth.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 |     prev: Link<T>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `tail`
[INFO] [stdout]  --> src/fourth.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     tail: Link<T>,
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `elem`
[INFO] [stdout]   --> src/fourth.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     elem: T,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `next`
[INFO] [stdout]   --> src/fourth.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     next: Link<T>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `prev`
[INFO] [stdout]   --> src/fourth.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 |     prev: Link<T>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.39s
[INFO] running `Command { std: "docker" "inspect" "d7ffab0656d286b1544537a0ad86cef751058aa67ebd4d3b489dfa1b882ae371", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d7ffab0656d286b1544537a0ad86cef751058aa67ebd4d3b489dfa1b882ae371", kill_on_drop: false }`
[INFO] [stdout] d7ffab0656d286b1544537a0ad86cef751058aa67ebd4d3b489dfa1b882ae371