[INFO] cloning repository https://github.com/changjiashuai/LinkedList
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/changjiashuai/LinkedList" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fchangjiashuai%2FLinkedList", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fchangjiashuai%2FLinkedList'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] dfea560e7c426552d3b3e0e89d52286d5f868e6d
[INFO] checking changjiashuai/LinkedList against master#507271bc119683008ec719ecee48814e8ac86c65 for pr-146440
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fchangjiashuai%2FLinkedList" "/workspace/builds/worker-5-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/changjiashuai/LinkedList
[INFO] finished tweaking git repo https://github.com/changjiashuai/LinkedList
[INFO] tweaked toml for git repo https://github.com/changjiashuai/LinkedList written to /workspace/builds/worker-5-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/changjiashuai/LinkedList on toolchain 507271bc119683008ec719ecee48814e8ac86c65
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+507271bc119683008ec719ecee48814e8ac86c65" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/changjiashuai/LinkedList 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" "+507271bc119683008ec719ecee48814e8ac86c65" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/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" "+507271bc119683008ec719ecee48814e8ac86c65" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a62ff37e2b22d59eed1372c5c926e79638254515995304b02c91a4aaed0f2a51
[INFO] running `Command { std: "docker" "start" "-a" "a62ff37e2b22d59eed1372c5c926e79638254515995304b02c91a4aaed0f2a51", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a62ff37e2b22d59eed1372c5c926e79638254515995304b02c91a4aaed0f2a51", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a62ff37e2b22d59eed1372c5c926e79638254515995304b02c91a4aaed0f2a51", kill_on_drop: false }`
[INFO] [stdout] a62ff37e2b22d59eed1372c5c926e79638254515995304b02c91a4aaed0f2a51
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/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" "+507271bc119683008ec719ecee48814e8ac86c65" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c9193e49236e5b7a4c4ce912ed81840fa65c8249a95ac69b7e1454e955e5b11d
[INFO] running `Command { std: "docker" "start" "-a" "c9193e49236e5b7a4c4ce912ed81840fa65c8249a95ac69b7e1454e955e5b11d", kill_on_drop: false }`
[INFO] [stderr]     Checking linked_list v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::mem`
[INFO] [stdout]  --> src/second.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::mem;
[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: `std::borrow::Borrow`
[INFO] [stdout]  --> src/third.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `mem`
[INFO] [stdout]  --> src/fifth.rs:1:11
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::{mem, ptr};
[INFO] [stdout]   |           ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::mem`
[INFO] [stdout]  --> src/second.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::mem;
[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: `std::borrow::Borrow`
[INFO] [stdout]  --> src/third.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `mem`
[INFO] [stdout]  --> src/fifth.rs:1:11
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::{mem, ptr};
[INFO] [stdout]   |           ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new` and `push` are never used
[INFO] [stdout]   --> src/second.rs:71:8
[INFO] [stdout]    |
[INFO] [stdout] 55 | impl<T> List<T> {
[INFO] [stdout]    | --------------- associated items in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 71 |     fn new() -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] ...
[INFO] [stdout] 77 |     fn push(&mut self, elem: 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: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/second.rs:60:17
[INFO] [stdout]    |
[INFO] [stdout] 60 |     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] 60 |     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/second.rs:67:21
[INFO] [stdout]    |
[INFO] [stdout] 67 |     pub fn iter_mut(&mut self) -> IterMut<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] 67 |     pub fn iter_mut(&mut self) -> IterMut<'_, T> {
[INFO] [stdout]    |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/fourth.rs:117:23
[INFO] [stdout]     |
[INFO] [stdout] 117 |     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] 117 |     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:123:27
[INFO] [stdout]     |
[INFO] [stdout] 123 |     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] 123 |     pub fn peek_front_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:168:22
[INFO] [stdout]     |
[INFO] [stdout] 168 |     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] 168 |     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:174:26
[INFO] [stdout]     |
[INFO] [stdout] 174 |     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] 174 |     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/second.rs:60:17
[INFO] [stdout]    |
[INFO] [stdout] 60 |     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] 60 |     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/second.rs:67:21
[INFO] [stdout]    |
[INFO] [stdout] 67 |     pub fn iter_mut(&mut self) -> IterMut<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] 67 |     pub fn iter_mut(&mut self) -> IterMut<'_, T> {
[INFO] [stdout]    |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/fourth.rs:117:23
[INFO] [stdout]     |
[INFO] [stdout] 117 |     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] 117 |     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:123:27
[INFO] [stdout]     |
[INFO] [stdout] 123 |     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] 123 |     pub fn peek_front_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:168:22
[INFO] [stdout]     |
[INFO] [stdout] 168 |     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] 168 |     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:174:26
[INFO] [stdout]     |
[INFO] [stdout] 174 |     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] 174 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stdout]     |                                                      +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.45s
[INFO] running `Command { std: "docker" "inspect" "c9193e49236e5b7a4c4ce912ed81840fa65c8249a95ac69b7e1454e955e5b11d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c9193e49236e5b7a4c4ce912ed81840fa65c8249a95ac69b7e1454e955e5b11d", kill_on_drop: false }`
[INFO] [stdout] c9193e49236e5b7a4c4ce912ed81840fa65c8249a95ac69b7e1454e955e5b11d
