[INFO] cloning repository https://github.com/MeMetoCoco3/too_many_linked_list
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/MeMetoCoco3/too_many_linked_list" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMeMetoCoco3%2Ftoo_many_linked_list", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMeMetoCoco3%2Ftoo_many_linked_list'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9f638476faa16785b4616eb16dccdf02951c1f30
[INFO] checking MeMetoCoco3/too_many_linked_list against try#0611f7de057c584b8771102fde7aed6c70c71d3b for pr-146440
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMeMetoCoco3%2Ftoo_many_linked_list" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/MeMetoCoco3/too_many_linked_list
[INFO] finished tweaking git repo https://github.com/MeMetoCoco3/too_many_linked_list
[INFO] tweaked toml for git repo https://github.com/MeMetoCoco3/too_many_linked_list written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/MeMetoCoco3/too_many_linked_list on toolchain 0611f7de057c584b8771102fde7aed6c70c71d3b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+0611f7de057c584b8771102fde7aed6c70c71d3b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/MeMetoCoco3/too_many_linked_list 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" "+0611f7de057c584b8771102fde7aed6c70c71d3b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+0611f7de057c584b8771102fde7aed6c70c71d3b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0fe6b53801a7bfb0f5d97172f30b270f1b3f280df248e3478839670bac85e0c9
[INFO] running `Command { std: "docker" "start" "-a" "0fe6b53801a7bfb0f5d97172f30b270f1b3f280df248e3478839670bac85e0c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0fe6b53801a7bfb0f5d97172f30b270f1b3f280df248e3478839670bac85e0c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0fe6b53801a7bfb0f5d97172f30b270f1b3f280df248e3478839670bac85e0c9", kill_on_drop: false }`
[INFO] [stdout] 0fe6b53801a7bfb0f5d97172f30b270f1b3f280df248e3478839670bac85e0c9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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" "RUSTDOCFLAGS=--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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+0611f7de057c584b8771102fde7aed6c70c71d3b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b9d39fb71ef68ab9012c36304b80753f16b19b5e40d384ccec34ebf1de7c314d
[INFO] running `Command { std: "docker" "start" "-a" "b9d39fb71ef68ab9012c36304b80753f16b19b5e40d384ccec34ebf1de7c314d", kill_on_drop: false }`
[INFO] [stderr]     Checking lists v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/second.rs:157:9
[INFO] [stdout]     |
[INFO] [stdout] 157 |     let mut iter = list.iter_mut();
[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: `iter`
[INFO] [stdout]    --> src/second.rs:157:9
[INFO] [stdout]     |
[INFO] [stdout] 157 |     let mut iter = list.iter_mut();
[INFO] [stdout]     |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_iter`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: struct `Iter` is never constructed
[INFO] [stdout]  --> src/second.rs:6:12
[INFO] [stdout]   |
[INFO] [stdout] 6 | pub struct Iter<'a, T>{
[INFO] [stdout]   |            ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: this `pub` struct has private fields, no public constructor, and is not otherwise reachable through the external API, so consider providing a public constructor or removing it
[INFO] [stdout]   = note: `#[deny(unused_unconstructable_pub_struct)]` (part of `#[deny(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `next` is never read
[INFO] [stdout]  --> src/second.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | pub struct Iter<'a, T>{
[INFO] [stdout]   |            ---- field in this struct
[INFO] [stdout] 7 |     next:Option<&'a Node<T>>,
[INFO] [stdout]   |     ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lists` (lib test) due to 1 previous error; 3 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error: struct `Iter` is never constructed
[INFO] [stdout]  --> src/second.rs:6:12
[INFO] [stdout]   |
[INFO] [stdout] 6 | pub struct Iter<'a, T>{
[INFO] [stdout]   |            ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: this `pub` struct has private fields, no public constructor, and is not otherwise reachable through the external API, so consider providing a public constructor or removing it
[INFO] [stdout]   = note: `#[deny(unused_unconstructable_pub_struct)]` (part of `#[deny(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `next` is never read
[INFO] [stdout]  --> src/second.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | pub struct Iter<'a, T>{
[INFO] [stdout]   |            ---- field in this struct
[INFO] [stdout] 7 |     next:Option<&'a Node<T>>,
[INFO] [stdout]   |     ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lists` (lib) due to 1 previous error; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "b9d39fb71ef68ab9012c36304b80753f16b19b5e40d384ccec34ebf1de7c314d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b9d39fb71ef68ab9012c36304b80753f16b19b5e40d384ccec34ebf1de7c314d", kill_on_drop: false }`
[INFO] [stdout] b9d39fb71ef68ab9012c36304b80753f16b19b5e40d384ccec34ebf1de7c314d
