[INFO] cloning repository https://github.com/detoxifiedplant/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/detoxifiedplant/linked-lists" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdetoxifiedplant%2Flinked-lists", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdetoxifiedplant%2Flinked-lists'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9daf9747bb01f3cfbca8fed1dce13a2be7eb4966
[INFO] checking detoxifiedplant/linked-lists against master#e43d139a82620a268d3828a73e12a8679339e8f8 for pr-143545
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdetoxifiedplant%2Flinked-lists" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/detoxifiedplant/linked-lists
[INFO] finished tweaking git repo https://github.com/detoxifiedplant/linked-lists
[INFO] tweaked toml for git repo https://github.com/detoxifiedplant/linked-lists written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/detoxifiedplant/linked-lists on toolchain e43d139a82620a268d3828a73e12a8679339e8f8
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+e43d139a82620a268d3828a73e12a8679339e8f8" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/detoxifiedplant/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" "+e43d139a82620a268d3828a73e12a8679339e8f8" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+e43d139a82620a268d3828a73e12a8679339e8f8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 298bd8efad84a72969a7d9569e1c2010527add49880e80243436c477c72e8099
[INFO] running `Command { std: "docker" "start" "-a" "298bd8efad84a72969a7d9569e1c2010527add49880e80243436c477c72e8099", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "298bd8efad84a72969a7d9569e1c2010527add49880e80243436c477c72e8099", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "298bd8efad84a72969a7d9569e1c2010527add49880e80243436c477c72e8099", kill_on_drop: false }`
[INFO] [stdout] 298bd8efad84a72969a7d9569e1c2010527add49880e80243436c477c72e8099
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+e43d139a82620a268d3828a73e12a8679339e8f8" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9c64506f982423828e577b07d387618457016ee76ca708d57d6f73b1c0927876
[INFO] running `Command { std: "docker" "start" "-a" "9c64506f982423828e577b07d387618457016ee76ca708d57d6f73b1c0927876", kill_on_drop: false }`
[INFO] [stderr]     Checking lists v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `in_front`
[INFO] [stdout]    --> src/unsafe_dqueue.rs:613:21
[INFO] [stdout]     |
[INFO] [stdout] 613 |                 let in_front = self.list.front.unwrap();
[INFO] [stdout]     |                     ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_in_front`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `in_back`
[INFO] [stdout]    --> src/unsafe_dqueue.rs:614:21
[INFO] [stdout]     |
[INFO] [stdout] 614 |                 let in_back = self.list.back.unwrap();
[INFO] [stdout]     |                     ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_in_back`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]    --> src/four.rs:128:24
[INFO] [stdout]     |
[INFO] [stdout] 128 | pub struct Iter<'a, T>(Option<Ref<'a, Node<T>>>);
[INFO] [stdout]     |            ----        ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |            |
[INFO] [stdout]     |            field in this struct
[INFO] [stdout]     |
[INFO] [stdout]     = help: consider removing this field
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]   --> src/four.rs:94:23
[INFO] [stdout]    |
[INFO] [stdout] 94 |     pub fn peek_front(&self) -> Option<Ref<T>> {
[INFO] [stdout]    |                       ^^^^^            ------ the lifetime gets resolved as `'_`
[INFO] [stdout]    |                       |
[INFO] [stdout]    |                       this lifetime flows to the output
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]    |
[INFO] [stdout] 94 |     pub fn peek_front(&self) -> Option<Ref<'_, T>> {
[INFO] [stdout]    |                                            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]    --> src/four.rs:101:22
[INFO] [stdout]     |
[INFO] [stdout] 101 |     pub fn peek_back(&self) -> Option<Ref<T>> {
[INFO] [stdout]     |                      ^^^^^            ------ the lifetime gets resolved as `'_`
[INFO] [stdout]     |                      |
[INFO] [stdout]     |                      this lifetime flows to the output
[INFO] [stdout]     |
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]     |
[INFO] [stdout] 101 |     pub fn peek_back(&self) -> Option<Ref<'_, T>> {
[INFO] [stdout]     |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]    --> src/four.rs:107:27
[INFO] [stdout]     |
[INFO] [stdout] 107 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stdout]     |                           ^^^^^^^^^            --------- the lifetime gets resolved as `'_`
[INFO] [stdout]     |                           |
[INFO] [stdout]     |                           this lifetime flows to the output
[INFO] [stdout]     |
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]     |
[INFO] [stdout] 107 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stdout]     |                                                       +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]    --> src/four.rs:113:26
[INFO] [stdout]     |
[INFO] [stdout] 113 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stdout]     |                          ^^^^^^^^^            --------- the lifetime gets resolved as `'_`
[INFO] [stdout]     |                          |
[INFO] [stdout]     |                          this lifetime flows to the output
[INFO] [stdout]     |
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]     |
[INFO] [stdout] 113 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stdout]     |                                                      +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]    --> src/unsafe_dqueue.rs:138:17
[INFO] [stdout]     |
[INFO] [stdout] 138 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stdout]     |                 ^^^^^     ------- the lifetime gets resolved as `'_`
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 this lifetime flows to the output
[INFO] [stdout]     |
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]     |
[INFO] [stdout] 138 |     pub fn iter(&self) -> Iter<'_, T> {
[INFO] [stdout]     |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]    --> src/unsafe_dqueue.rs:147:21
[INFO] [stdout]     |
[INFO] [stdout] 147 |     pub fn iter_mut(&self) -> IterMut<T> {
[INFO] [stdout]     |                     ^^^^^     ---------- the lifetime gets resolved as `'_`
[INFO] [stdout]     |                     |
[INFO] [stdout]     |                     this lifetime flows to the output
[INFO] [stdout]     |
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]     |
[INFO] [stdout] 147 |     pub fn iter_mut(&self) -> IterMut<'_, T> {
[INFO] [stdout]     |                                       +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]    --> src/unsafe_dqueue.rs:160:23
[INFO] [stdout]     |
[INFO] [stdout] 160 |     pub fn cursor_mut(&mut self) -> CursorMut<T> {
[INFO] [stdout]     |                       ^^^^^^^^^     ------------ the lifetime gets resolved as `'_`
[INFO] [stdout]     |                       |
[INFO] [stdout]     |                       this lifetime flows to the output
[INFO] [stdout]     |
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]     |
[INFO] [stdout] 160 |     pub fn cursor_mut(&mut self) -> CursorMut<'_, T> {
[INFO] [stdout]     |                                               +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `in_front`
[INFO] [stdout]    --> src/unsafe_dqueue.rs:613:21
[INFO] [stdout]     |
[INFO] [stdout] 613 |                 let in_front = self.list.front.unwrap();
[INFO] [stdout]     |                     ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_in_front`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `in_back`
[INFO] [stdout]    --> src/unsafe_dqueue.rs:614:21
[INFO] [stdout]     |
[INFO] [stdout] 614 |                 let in_back = self.list.back.unwrap();
[INFO] [stdout]     |                     ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_in_back`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]    --> src/four.rs:128:24
[INFO] [stdout]     |
[INFO] [stdout] 128 | pub struct Iter<'a, T>(Option<Ref<'a, Node<T>>>);
[INFO] [stdout]     |            ----        ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |            |
[INFO] [stdout]     |            field in this struct
[INFO] [stdout]     |
[INFO] [stdout]     = help: consider removing this field
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]   --> src/four.rs:94:23
[INFO] [stdout]    |
[INFO] [stdout] 94 |     pub fn peek_front(&self) -> Option<Ref<T>> {
[INFO] [stdout]    |                       ^^^^^            ------ the lifetime gets resolved as `'_`
[INFO] [stdout]    |                       |
[INFO] [stdout]    |                       this lifetime flows to the output
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]    |
[INFO] [stdout] 94 |     pub fn peek_front(&self) -> Option<Ref<'_, T>> {
[INFO] [stdout]    |                                            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]    --> src/four.rs:101:22
[INFO] [stdout]     |
[INFO] [stdout] 101 |     pub fn peek_back(&self) -> Option<Ref<T>> {
[INFO] [stdout]     |                      ^^^^^            ------ the lifetime gets resolved as `'_`
[INFO] [stdout]     |                      |
[INFO] [stdout]     |                      this lifetime flows to the output
[INFO] [stdout]     |
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]     |
[INFO] [stdout] 101 |     pub fn peek_back(&self) -> Option<Ref<'_, T>> {
[INFO] [stdout]     |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]    --> src/four.rs:107:27
[INFO] [stdout]     |
[INFO] [stdout] 107 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stdout]     |                           ^^^^^^^^^            --------- the lifetime gets resolved as `'_`
[INFO] [stdout]     |                           |
[INFO] [stdout]     |                           this lifetime flows to the output
[INFO] [stdout]     |
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]     |
[INFO] [stdout] 107 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stdout]     |                                                       +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]    --> src/four.rs:113:26
[INFO] [stdout]     |
[INFO] [stdout] 113 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stdout]     |                          ^^^^^^^^^            --------- the lifetime gets resolved as `'_`
[INFO] [stdout]     |                          |
[INFO] [stdout]     |                          this lifetime flows to the output
[INFO] [stdout]     |
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]     |
[INFO] [stdout] 113 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stdout]     |                                                      +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]    --> src/unsafe_dqueue.rs:138:17
[INFO] [stdout]     |
[INFO] [stdout] 138 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stdout]     |                 ^^^^^     ------- the lifetime gets resolved as `'_`
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 this lifetime flows to the output
[INFO] [stdout]     |
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]     |
[INFO] [stdout] 138 |     pub fn iter(&self) -> Iter<'_, T> {
[INFO] [stdout]     |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]    --> src/unsafe_dqueue.rs:147:21
[INFO] [stdout]     |
[INFO] [stdout] 147 |     pub fn iter_mut(&self) -> IterMut<T> {
[INFO] [stdout]     |                     ^^^^^     ---------- the lifetime gets resolved as `'_`
[INFO] [stdout]     |                     |
[INFO] [stdout]     |                     this lifetime flows to the output
[INFO] [stdout]     |
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]     |
[INFO] [stdout] 147 |     pub fn iter_mut(&self) -> IterMut<'_, T> {
[INFO] [stdout]     |                                       +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]    --> src/unsafe_dqueue.rs:160:23
[INFO] [stdout]     |
[INFO] [stdout] 160 |     pub fn cursor_mut(&mut self) -> CursorMut<T> {
[INFO] [stdout]     |                       ^^^^^^^^^     ------------ the lifetime gets resolved as `'_`
[INFO] [stdout]     |                       |
[INFO] [stdout]     |                       this lifetime flows to the output
[INFO] [stdout]     |
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]     |
[INFO] [stdout] 160 |     pub fn cursor_mut(&mut self) -> CursorMut<'_, T> {
[INFO] [stdout]     |                                               +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.24s
[INFO] running `Command { std: "docker" "inspect" "9c64506f982423828e577b07d387618457016ee76ca708d57d6f73b1c0927876", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9c64506f982423828e577b07d387618457016ee76ca708d57d6f73b1c0927876", kill_on_drop: false }`
[INFO] [stdout] 9c64506f982423828e577b07d387618457016ee76ca708d57d6f73b1c0927876