[INFO] cloning repository https://github.com/bsjhx/too-many-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/bsjhx/too-many-linked-lists" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbsjhx%2Ftoo-many-linked-lists", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbsjhx%2Ftoo-many-linked-lists'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] dfffc07f635d3152af55f4f58932034189310015
[INFO] checking bsjhx/too-many-linked-lists against try#0611f7de057c584b8771102fde7aed6c70c71d3b for pr-146440
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbsjhx%2Ftoo-many-linked-lists" "/workspace/builds/worker-1-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/bsjhx/too-many-linked-lists
[INFO] finished tweaking git repo https://github.com/bsjhx/too-many-linked-lists
[INFO] tweaked toml for git repo https://github.com/bsjhx/too-many-linked-lists written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/bsjhx/too-many-linked-lists 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/bsjhx/too-many-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" "+0611f7de057c584b8771102fde7aed6c70c71d3b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] c117afaf8c93409969e5d8ae53108080028ee803a720c07f7a7065d4d1b81212
[INFO] running `Command { std: "docker" "start" "-a" "c117afaf8c93409969e5d8ae53108080028ee803a720c07f7a7065d4d1b81212", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c117afaf8c93409969e5d8ae53108080028ee803a720c07f7a7065d4d1b81212", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c117afaf8c93409969e5d8ae53108080028ee803a720c07f7a7065d4d1b81212", kill_on_drop: false }`
[INFO] [stdout] c117afaf8c93409969e5d8ae53108080028ee803a720c07f7a7065d4d1b81212
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] c3b9c88f7675e7641aa313dc44c733c8d1a7bda98d23e2920b0987d35a679d72
[INFO] running `Command { std: "docker" "start" "-a" "c3b9c88f7675e7641aa313dc44c733c8d1a7bda98d23e2920b0987d35a679d72", kill_on_drop: false }`
[INFO] [stderr]     Checking lists v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `crate::first::List`
[INFO] [stdout]   --> src/first.rs:61:9
[INFO] [stdout]    |
[INFO] [stdout] 61 |     use crate::first::List;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `super::*`
[INFO] [stdout]    --> src/second.rs:116:9
[INFO] [stdout]     |
[INFO] [stdout] 116 |     use super::*;
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: struct `List` is never constructed
[INFO] [stdout]  --> src/first.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct List {
[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: variant `More` is never constructed
[INFO] [stdout]  --> src/first.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | enum Link {
[INFO] [stdout]   |      ---- variant in this enum
[INFO] [stdout] 8 |     Empty,
[INFO] [stdout] 9 |     More(Box<Node>)
[INFO] [stdout]   |     ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `elem` is never read
[INFO] [stdout]   --> src/first.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 12 | struct Node {
[INFO] [stdout]    |        ---- field in this struct
[INFO] [stdout] 13 |     elem: i32,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `push`, and `pop` are never used
[INFO] [stdout]   --> src/first.rs:18:8
[INFO] [stdout]    |
[INFO] [stdout] 17 | impl List {
[INFO] [stdout]    | --------- associated items in this implementation
[INFO] [stdout] 18 |     fn new() -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] ...
[INFO] [stdout] 24 |     fn push(&mut self, elem: i32) {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 33 |     fn pop(&mut self) -> Option<i32> {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/second.rs:33:17
[INFO] [stdout]    |
[INFO] [stdout] 33 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stdout]    |                 ^^^^^     ^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |                 |
[INFO] [stdout]    |                 the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 33 |     pub fn iter(&self) -> Iter<'_, T> {
[INFO] [stdout]    |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/fourth.rs:95:23
[INFO] [stdout]    |
[INFO] [stdout] 95 |     pub fn peek_front(&self) -> Option<Ref<T>> {
[INFO] [stdout]    |                       ^^^^^            ^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |                       |
[INFO] [stdout]    |                       the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 95 |     pub fn peek_front(&self) -> Option<Ref<'_, T>> {
[INFO] [stdout]    |                                            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/fourth.rs:101:22
[INFO] [stdout]     |
[INFO] [stdout] 101 |     pub fn peek_back(&self) -> Option<Ref<T>> {
[INFO] [stdout]     |                      ^^^^^            ^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                      |
[INFO] [stdout]     |                      the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 101 |     pub fn peek_back(&self) -> Option<Ref<'_, T>> {
[INFO] [stdout]     |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/fourth.rs:107:26
[INFO] [stdout]     |
[INFO] [stdout] 107 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stdout]     |                          ^^^^^^^^^            ^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                          |
[INFO] [stdout]     |                          the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 107 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stdout]     |                                                      +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/fourth.rs:113:27
[INFO] [stdout]     |
[INFO] [stdout] 113 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stdout]     |                           ^^^^^^^^^            ^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                           |
[INFO] [stdout]     |                           the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 113 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stdout]     |                                                       +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lists` (lib) due to 1 previous error; 10 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/second.rs:33:17
[INFO] [stdout]    |
[INFO] [stdout] 33 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stdout]    |                 ^^^^^     ^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |                 |
[INFO] [stdout]    |                 the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 33 |     pub fn iter(&self) -> Iter<'_, T> {
[INFO] [stdout]    |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/fourth.rs:95:23
[INFO] [stdout]    |
[INFO] [stdout] 95 |     pub fn peek_front(&self) -> Option<Ref<T>> {
[INFO] [stdout]    |                       ^^^^^            ^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |                       |
[INFO] [stdout]    |                       the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 95 |     pub fn peek_front(&self) -> Option<Ref<'_, T>> {
[INFO] [stdout]    |                                            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/fourth.rs:101:22
[INFO] [stdout]     |
[INFO] [stdout] 101 |     pub fn peek_back(&self) -> Option<Ref<T>> {
[INFO] [stdout]     |                      ^^^^^            ^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                      |
[INFO] [stdout]     |                      the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 101 |     pub fn peek_back(&self) -> Option<Ref<'_, T>> {
[INFO] [stdout]     |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/fourth.rs:107:26
[INFO] [stdout]     |
[INFO] [stdout] 107 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stdout]     |                          ^^^^^^^^^            ^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                          |
[INFO] [stdout]     |                          the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 107 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stdout]     |                                                      +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/fourth.rs:113:27
[INFO] [stdout]     |
[INFO] [stdout] 113 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stdout]     |                           ^^^^^^^^^            ^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                           |
[INFO] [stdout]     |                           the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 113 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stdout]     |                                                       +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "c3b9c88f7675e7641aa313dc44c733c8d1a7bda98d23e2920b0987d35a679d72", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c3b9c88f7675e7641aa313dc44c733c8d1a7bda98d23e2920b0987d35a679d72", kill_on_drop: false }`
[INFO] [stdout] c3b9c88f7675e7641aa313dc44c733c8d1a7bda98d23e2920b0987d35a679d72
