[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#9543f8ea2aae74b8f13ac2a6e6c0ecdca9810869 for pr-129249
[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] validating manifest of git repo https://github.com/MeMetoCoco3/too_many_linked_list on toolchain 9543f8ea2aae74b8f13ac2a6e6c0ecdca9810869
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+9543f8ea2aae74b8f13ac2a6e6c0ecdca9810869" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[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] 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" "+9543f8ea2aae74b8f13ac2a6e6c0ecdca9810869" "fetch" "--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-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+9543f8ea2aae74b8f13ac2a6e6c0ecdca9810869" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1ecd5b82e7a640143a8e791f7634d924b3db0fe1e1b3eb4c68625e215675e85a
[INFO] running `Command { std: "docker" "start" "-a" "1ecd5b82e7a640143a8e791f7634d924b3db0fe1e1b3eb4c68625e215675e85a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1ecd5b82e7a640143a8e791f7634d924b3db0fe1e1b3eb4c68625e215675e85a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1ecd5b82e7a640143a8e791f7634d924b3db0fe1e1b3eb4c68625e215675e85a", kill_on_drop: false }`
[INFO] [stdout] 1ecd5b82e7a640143a8e791f7634d924b3db0fe1e1b3eb4c68625e215675e85a
[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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+9543f8ea2aae74b8f13ac2a6e6c0ecdca9810869" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b339ff668b0eebe1655d1c3d1ba0b445b94b05281f265b4b7caa6a900f4ff923
[INFO] running `Command { std: "docker" "start" "-a" "b339ff668b0eebe1655d1c3d1ba0b445b94b05281f265b4b7caa6a900f4ff923", kill_on_drop: false }`
[INFO] [stderr]     Checking lists v0.1.0 (/opt/rustwide/workdir)
[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)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `iter`
[INFO] [stdout]    --> src/second.rs:157:13
[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)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[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)]` 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)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.14s
[INFO] running `Command { std: "docker" "inspect" "b339ff668b0eebe1655d1c3d1ba0b445b94b05281f265b4b7caa6a900f4ff923", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b339ff668b0eebe1655d1c3d1ba0b445b94b05281f265b4b7caa6a900f4ff923", kill_on_drop: false }`
[INFO] [stdout] b339ff668b0eebe1655d1c3d1ba0b445b94b05281f265b4b7caa6a900f4ff923