[INFO] cloning repository https://github.com/hnefatl/rust-linked-lists
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/hnefatl/rust-linked-lists" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhnefatl%2Frust-linked-lists", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhnefatl%2Frust-linked-lists'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] fc93bdcc2983f22ccbacc827da29434854e1c82f
[INFO] checking hnefatl/rust-linked-lists against try#b1f2594eac607c1f051534800237eeedb5590a49 for pr-139493-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhnefatl%2Frust-linked-lists" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/hnefatl/rust-linked-lists
[INFO] finished tweaking git repo https://github.com/hnefatl/rust-linked-lists
[INFO] tweaked toml for git repo https://github.com/hnefatl/rust-linked-lists written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/hnefatl/rust-linked-lists on toolchain b1f2594eac607c1f051534800237eeedb5590a49
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b1f2594eac607c1f051534800237eeedb5590a49" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/hnefatl/rust-linked-lists 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" "+b1f2594eac607c1f051534800237eeedb5590a49" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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:aa71247004a7fa38d13ec170f48f06cdedf5bc50b2a8645e56ed7e992e6fa513" "/opt/rustwide/cargo-home/bin/cargo" "+b1f2594eac607c1f051534800237eeedb5590a49" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 68e46df5b2cf6a3a5ebe9ef130442d6955c7c141d156a1e88f1bea70bd7d2568
[INFO] running `Command { std: "docker" "start" "-a" "68e46df5b2cf6a3a5ebe9ef130442d6955c7c141d156a1e88f1bea70bd7d2568", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "68e46df5b2cf6a3a5ebe9ef130442d6955c7c141d156a1e88f1bea70bd7d2568", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "68e46df5b2cf6a3a5ebe9ef130442d6955c7c141d156a1e88f1bea70bd7d2568", kill_on_drop: false }`
[INFO] [stdout] 68e46df5b2cf6a3a5ebe9ef130442d6955c7c141d156a1e88f1bea70bd7d2568
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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:aa71247004a7fa38d13ec170f48f06cdedf5bc50b2a8645e56ed7e992e6fa513" "/opt/rustwide/cargo-home/bin/cargo" "+b1f2594eac607c1f051534800237eeedb5590a49" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d554e9f163ea749bccd7538c09460b85f1e1dc70b4f854238959f7de1977623a
[INFO] running `Command { std: "docker" "start" "-a" "d554e9f163ea749bccd7538c09460b85f1e1dc70b4f854238959f7de1977623a", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.62
[INFO] [stderr]    Compiling getrandom v0.1.9
[INFO] [stderr]     Checking cfg-if v0.1.9
[INFO] [stderr]     Checking ppv-lite86 v0.2.5
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling unicode-segmentation v1.3.0
[INFO] [stderr]     Checking strum v0.15.0
[INFO] [stderr]     Checking c2-chacha v0.2.2
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]     Checking rand_core v0.5.0
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking rand v0.7.0
[INFO] [stderr]    Compiling strum_macros v0.15.0
[INFO] [stderr]     Checking linked-lists v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 4.80s
[INFO] [stdout] warning: trait `List` is never used
[INFO] [stdout]  --> src/list.rs:1:11
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub trait List<T> {
[INFO] [stdout]   |           ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `SingleLinked` is never constructed
[INFO] [stdout]  --> src/singlelinked.rs:4:12
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub struct SingleLinked<T> {
[INFO] [stdout]   |            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Node` is never used
[INFO] [stdout]  --> src/singlelinked.rs:8:6
[INFO] [stdout]   |
[INFO] [stdout] 8 | enum Node<T> {
[INFO] [stdout]   |      ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/singlelinked.rs:15:12
[INFO] [stdout]    |
[INFO] [stdout] 14 | impl<T> SingleLinked<T> {
[INFO] [stdout]    | ----------------------- associated function in this implementation
[INFO] [stdout] 15 |     pub fn new() -> SingleLinked<T> {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `traverse_with` is never used
[INFO] [stdout]   --> src/singlelinked.rs:21:8
[INFO] [stdout]    |
[INFO] [stdout] 19 | impl<T> Node<T> {
[INFO] [stdout]    | --------------- method in this implementation
[INFO] [stdout] 20 |     // Walk along the list, calling a function on the value/tail each non-null point
[INFO] [stdout] 21 |     fn traverse_with<F>(&mut self, f: F) where F: Fn(&mut T, &mut Node<T>) {
[INFO] [stdout]    |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `len` is never used
[INFO] [stdout]   --> src/list.rs:10:8
[INFO] [stdout]    |
[INFO] [stdout]  1 | pub trait List<T> {
[INFO] [stdout]    |           ---- method in this trait
[INFO] [stdout] ...
[INFO] [stdout] 10 |     fn len(&self) -> usize;
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `traverse_with` is never used
[INFO] [stdout]   --> src/singlelinked.rs:21:8
[INFO] [stdout]    |
[INFO] [stdout] 19 | impl<T> Node<T> {
[INFO] [stdout]    | --------------- method in this implementation
[INFO] [stdout] 20 |     // Walk along the list, calling a function on the value/tail each non-null point
[INFO] [stdout] 21 |     fn traverse_with<F>(&mut self, f: F) where F: Fn(&mut T, &mut Node<T>) {
[INFO] [stdout]    |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "d554e9f163ea749bccd7538c09460b85f1e1dc70b4f854238959f7de1977623a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d554e9f163ea749bccd7538c09460b85f1e1dc70b4f854238959f7de1977623a", kill_on_drop: false }`
[INFO] [stdout] d554e9f163ea749bccd7538c09460b85f1e1dc70b4f854238959f7de1977623a