[INFO] cloning repository https://github.com/kingfree/rust-lists
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/kingfree/rust-lists" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkingfree%2Frust-lists", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkingfree%2Frust-lists'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3b529328280374620cafa34ab8a6f5e857ec8d69
[INFO] testing kingfree/rust-lists against try#c2e32f1c9652b13ed99608599c1e855462f421f3 for pr-146098-7
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkingfree%2Frust-lists" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/kingfree/rust-lists
[INFO] finished tweaking git repo https://github.com/kingfree/rust-lists
[INFO] tweaked toml for git repo https://github.com/kingfree/rust-lists written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/kingfree/rust-lists on toolchain c2e32f1c9652b13ed99608599c1e855462f421f3
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/kingfree/rust-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" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 85b070665e323affd023441910432f94697802191b8c8d6920a8bffcd71b64fb
[INFO] running `Command { std: "docker" "start" "-a" "85b070665e323affd023441910432f94697802191b8c8d6920a8bffcd71b64fb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "85b070665e323affd023441910432f94697802191b8c8d6920a8bffcd71b64fb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "85b070665e323affd023441910432f94697802191b8c8d6920a8bffcd71b64fb", kill_on_drop: false }`
[INFO] [stdout] 85b070665e323affd023441910432f94697802191b8c8d6920a8bffcd71b64fb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bf99c70eea94dde4fe55fd84b4468b805ad0f118872b1a31df8a271e61b1c787
[INFO] running `Command { std: "docker" "start" "-a" "bf99c70eea94dde4fe55fd84b4468b805ad0f118872b1a31df8a271e61b1c787", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust-lists v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `super::List`
[INFO] [stdout]    --> src/fifth.rs:139:9
[INFO] [stdout]     |
[INFO] [stdout] 139 |     use super::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 variable: `next`
[INFO] [stdout]    --> src/fourth.rs:171:18
[INFO] [stdout]     |
[INFO] [stdout] 171 |             let (next, elem) = Ref::map_split(node_ref, |node| (&node.next, &node.elem));
[INFO] [stdout]     |                  ^^^^ help: if this is intentional, prefix it with an underscore: `_next`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `List` is never constructed
[INFO] [stdout]  --> src/silly1.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct 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: multiple associated items are never used
[INFO] [stdout]   --> src/silly1.rs:7:8
[INFO] [stdout]    |
[INFO] [stdout]  6 | impl<T> List<T> {
[INFO] [stdout]    | --------------- associated items in this implementation
[INFO] [stdout]  7 |     fn new() -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] ...
[INFO] [stdout] 14 |     pub fn push_left(&mut self, elem: T) {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 17 |     pub fn push_right(&mut self, elem: T) {
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 20 |     pub fn pop_left(&mut self) -> Option<T> {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 23 |     pub fn pop_right(&mut self) -> Option<T> {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 26 |     pub fn peek_left(&self) -> Option<&T> {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 29 |     pub fn peek_right(&self) -> Option<&T> {
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 32 |     pub fn peek_left_mut(&mut self) -> Option<&mut T> {
[INFO] [stdout]    |            ^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 35 |     pub fn peek_right_mut(&mut self) -> Option<&mut T> {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 39 |     pub fn go_left(&mut self) -> bool {
[INFO] [stdout]    |            ^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 48 |     pub fn go_right(&mut self) -> bool {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/fourth.rs:77:23
[INFO] [stdout]    |
[INFO] [stdout] 77 |     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]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 77 |     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:113:22
[INFO] [stdout]     |
[INFO] [stdout] 113 |     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] 113 |     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:119:26
[INFO] [stdout]     |
[INFO] [stdout] 119 |     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] 119 |     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:125:27
[INFO] [stdout]     |
[INFO] [stdout] 125 |     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] 125 |     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:162:17
[INFO] [stdout]     |
[INFO] [stdout] 162 |     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] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 162 |     pub fn iter(&self) -> Iter<'_, T> {
[INFO] [stdout]     |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.30s
[INFO] running `Command { std: "docker" "inspect" "bf99c70eea94dde4fe55fd84b4468b805ad0f118872b1a31df8a271e61b1c787", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bf99c70eea94dde4fe55fd84b4468b805ad0f118872b1a31df8a271e61b1c787", kill_on_drop: false }`
[INFO] [stdout] bf99c70eea94dde4fe55fd84b4468b805ad0f118872b1a31df8a271e61b1c787
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] cb47c8cac79a3a5e46094b5b767e72dd95a5545ce403326e6890acb1610449b6
[INFO] running `Command { std: "docker" "start" "-a" "cb47c8cac79a3a5e46094b5b767e72dd95a5545ce403326e6890acb1610449b6", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust-lists v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `super::List`
[INFO] [stdout]    --> src/fifth.rs:139:9
[INFO] [stdout]     |
[INFO] [stdout] 139 |     use super::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 variable: `next`
[INFO] [stdout]    --> src/fourth.rs:171:18
[INFO] [stdout]     |
[INFO] [stdout] 171 |             let (next, elem) = Ref::map_split(node_ref, |node| (&node.next, &node.elem));
[INFO] [stdout]     |                  ^^^^ help: if this is intentional, prefix it with an underscore: `_next`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `List` is never constructed
[INFO] [stdout]  --> src/silly1.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct 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: multiple associated items are never used
[INFO] [stdout]   --> src/silly1.rs:7:8
[INFO] [stdout]    |
[INFO] [stdout]  6 | impl<T> List<T> {
[INFO] [stdout]    | --------------- associated items in this implementation
[INFO] [stdout]  7 |     fn new() -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] ...
[INFO] [stdout] 14 |     pub fn push_left(&mut self, elem: T) {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 17 |     pub fn push_right(&mut self, elem: T) {
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 20 |     pub fn pop_left(&mut self) -> Option<T> {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 23 |     pub fn pop_right(&mut self) -> Option<T> {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 26 |     pub fn peek_left(&self) -> Option<&T> {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 29 |     pub fn peek_right(&self) -> Option<&T> {
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 32 |     pub fn peek_left_mut(&mut self) -> Option<&mut T> {
[INFO] [stdout]    |            ^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 35 |     pub fn peek_right_mut(&mut self) -> Option<&mut T> {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 39 |     pub fn go_left(&mut self) -> bool {
[INFO] [stdout]    |            ^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 48 |     pub fn go_right(&mut self) -> bool {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/fourth.rs:77:23
[INFO] [stdout]    |
[INFO] [stdout] 77 |     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]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 77 |     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:113:22
[INFO] [stdout]     |
[INFO] [stdout] 113 |     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] 113 |     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:119:26
[INFO] [stdout]     |
[INFO] [stdout] 119 |     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] 119 |     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:125:27
[INFO] [stdout]     |
[INFO] [stdout] 125 |     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] 125 |     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:162:17
[INFO] [stdout]     |
[INFO] [stdout] 162 |     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] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 162 |     pub fn iter(&self) -> Iter<'_, T> {
[INFO] [stdout]     |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `next`
[INFO] [stdout]    --> src/fourth.rs:171:18
[INFO] [stdout]     |
[INFO] [stdout] 171 |             let (next, elem) = Ref::map_split(node_ref, |node| (&node.next, &node.elem));
[INFO] [stdout]     |                  ^^^^ help: if this is intentional, prefix it with an underscore: `_next`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `peek_left_mut`, `peek_right_mut`, and `go_right` are never used
[INFO] [stdout]   --> src/silly1.rs:32:12
[INFO] [stdout]    |
[INFO] [stdout]  6 | impl<T> List<T> {
[INFO] [stdout]    | --------------- methods in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 32 |     pub fn peek_left_mut(&mut self) -> Option<&mut T> {
[INFO] [stdout]    |            ^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 35 |     pub fn peek_right_mut(&mut self) -> Option<&mut T> {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 48 |     pub fn go_right(&mut self) -> bool {
[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/fourth.rs:77:23
[INFO] [stdout]    |
[INFO] [stdout] 77 |     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]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 77 |     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:113:22
[INFO] [stdout]     |
[INFO] [stdout] 113 |     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] 113 |     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:119:26
[INFO] [stdout]     |
[INFO] [stdout] 119 |     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] 119 |     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:125:27
[INFO] [stdout]     |
[INFO] [stdout] 125 |     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] 125 |     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:162:17
[INFO] [stdout]     |
[INFO] [stdout] 162 |     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] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 162 |     pub fn iter(&self) -> Iter<'_, T> {
[INFO] [stdout]     |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.59s
[INFO] running `Command { std: "docker" "inspect" "cb47c8cac79a3a5e46094b5b767e72dd95a5545ce403326e6890acb1610449b6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cb47c8cac79a3a5e46094b5b767e72dd95a5545ce403326e6890acb1610449b6", kill_on_drop: false }`
[INFO] [stdout] cb47c8cac79a3a5e46094b5b767e72dd95a5545ce403326e6890acb1610449b6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 4e2952385431f41fe22b5c34f56b946dcc2d7c0bd663e130fede6ab062b79ea1
[INFO] running `Command { std: "docker" "start" "-a" "4e2952385431f41fe22b5c34f56b946dcc2d7c0bd663e130fede6ab062b79ea1", kill_on_drop: false }`
[INFO] [stderr] warning: unused import: `super::List`
[INFO] [stderr]    --> src/fifth.rs:139:9
[INFO] [stderr]     |
[INFO] [stderr] 139 |     use super::List;
[INFO] [stderr]     |         ^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `next`
[INFO] [stderr]    --> src/fourth.rs:171:18
[INFO] [stderr]     |
[INFO] [stderr] 171 |             let (next, elem) = Ref::map_split(node_ref, |node| (&node.next, &node.elem));
[INFO] [stderr]     |                  ^^^^ help: if this is intentional, prefix it with an underscore: `_next`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: struct `List` is never constructed
[INFO] [stderr]  --> src/silly1.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | struct List<T> {
[INFO] [stderr]   |        ^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: multiple associated items are never used
[INFO] [stderr]   --> src/silly1.rs:7:8
[INFO] [stderr]    |
[INFO] [stderr]  6 | impl<T> List<T> {
[INFO] [stderr]    | --------------- associated items in this implementation
[INFO] [stderr]  7 |     fn new() -> Self {
[INFO] [stderr]    |        ^^^
[INFO] [stderr] ...
[INFO] [stderr] 14 |     pub fn push_left(&mut self, elem: T) {
[INFO] [stderr]    |            ^^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 17 |     pub fn push_right(&mut self, elem: T) {
[INFO] [stderr]    |            ^^^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 20 |     pub fn pop_left(&mut self) -> Option<T> {
[INFO] [stderr]    |            ^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 23 |     pub fn pop_right(&mut self) -> Option<T> {
[INFO] [stderr]    |            ^^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 26 |     pub fn peek_left(&self) -> Option<&T> {
[INFO] [stderr]    |            ^^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 29 |     pub fn peek_right(&self) -> Option<&T> {
[INFO] [stderr]    |            ^^^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 32 |     pub fn peek_left_mut(&mut self) -> Option<&mut T> {
[INFO] [stderr]    |            ^^^^^^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 35 |     pub fn peek_right_mut(&mut self) -> Option<&mut T> {
[INFO] [stderr]    |            ^^^^^^^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 39 |     pub fn go_left(&mut self) -> bool {
[INFO] [stderr]    |            ^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 48 |     pub fn go_right(&mut self) -> bool {
[INFO] [stderr]    |            ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stderr]   --> src/fourth.rs:77:23
[INFO] [stderr]    |
[INFO] [stderr] 77 |     pub fn peek_front(&self) -> Option<Ref<T>> {
[INFO] [stderr]    |                       ^^^^^            ^^^^^^ the same lifetime is hidden here
[INFO] [stderr]    |                       |
[INFO] [stderr]    |                       the lifetime is elided here
[INFO] [stderr]    |
[INFO] [stderr]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stderr]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stderr] help: use `'_` for type paths
[INFO] [stderr]    |
[INFO] [stderr] 77 |     pub fn peek_front(&self) -> Option<Ref<'_, T>> {
[INFO] [stderr]    |                                            +++
[INFO] [stderr] 
[INFO] [stderr] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stderr]    --> src/fourth.rs:113:22
[INFO] [stderr]     |
[INFO] [stderr] 113 |     pub fn peek_back(&self) -> Option<Ref<T>> {
[INFO] [stderr]     |                      ^^^^^            ^^^^^^ the same lifetime is hidden here
[INFO] [stderr]     |                      |
[INFO] [stderr]     |                      the lifetime is elided here
[INFO] [stderr]     |
[INFO] [stderr]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stderr] help: use `'_` for type paths
[INFO] [stderr]     |
[INFO] [stderr] 113 |     pub fn peek_back(&self) -> Option<Ref<'_, T>> {
[INFO] [stderr]     |                                           +++
[INFO] [stderr] 
[INFO] [stderr] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stderr]    --> src/fourth.rs:119:26
[INFO] [stderr]     |
[INFO] [stderr] 119 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stderr]     |                          ^^^^^^^^^            ^^^^^^^^^ the same lifetime is hidden here
[INFO] [stderr]     |                          |
[INFO] [stderr]     |                          the lifetime is elided here
[INFO] [stderr]     |
[INFO] [stderr]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stderr] help: use `'_` for type paths
[INFO] [stderr]     |
[INFO] [stderr] 119 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stderr]     |                                                      +++
[INFO] [stderr] 
[INFO] [stderr] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stderr]    --> src/fourth.rs:125:27
[INFO] [stderr]     |
[INFO] [stderr] 125 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stderr]     |                           ^^^^^^^^^            ^^^^^^^^^ the same lifetime is hidden here
[INFO] [stderr]     |                           |
[INFO] [stderr]     |                           the lifetime is elided here
[INFO] [stderr]     |
[INFO] [stderr]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stderr] help: use `'_` for type paths
[INFO] [stderr]     |
[INFO] [stderr] 125 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stderr]     |                                                       +++
[INFO] [stderr] 
[INFO] [stderr] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stderr]    --> src/fourth.rs:162:17
[INFO] [stderr]     |
[INFO] [stderr] 162 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stderr]     |                 ^^^^^     ^^^^^^^ the same lifetime is hidden here
[INFO] [stderr]     |                 |
[INFO] [stderr]     |                 the lifetime is elided here
[INFO] [stderr]     |
[INFO] [stderr]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stderr] help: use `'_` for type paths
[INFO] [stderr]     |
[INFO] [stderr] 162 |     pub fn iter(&self) -> Iter<'_, T> {
[INFO] [stderr]     |                                +++
[INFO] [stderr] 
[INFO] [stderr] warning: `rust-lists` (lib) generated 9 warnings (run `cargo fix --lib -p rust-lists` to apply 7 suggestions)
[INFO] [stderr] warning: methods `peek_left_mut`, `peek_right_mut`, and `go_right` are never used
[INFO] [stderr]   --> src/silly1.rs:32:12
[INFO] [stderr]    |
[INFO] [stderr]  6 | impl<T> List<T> {
[INFO] [stderr]    | --------------- methods in this implementation
[INFO] [stderr] ...
[INFO] [stderr] 32 |     pub fn peek_left_mut(&mut self) -> Option<&mut T> {
[INFO] [stderr]    |            ^^^^^^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 35 |     pub fn peek_right_mut(&mut self) -> Option<&mut T> {
[INFO] [stderr]    |            ^^^^^^^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 48 |     pub fn go_right(&mut self) -> bool {
[INFO] [stderr]    |            ^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: `rust-lists` (lib test) generated 7 warnings (6 duplicates)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.09s
[INFO] [stderr]      Running unittests src/lib.rs (/opt/rustwide/target/debug/deps/rust_lists-4c08f0dc88a6027f)
[INFO] [stdout] 
[INFO] [stdout] running 19 tests
[INFO] [stdout] test fifth::test::basics ... ok
[INFO] [stdout] test fifth::test::iter ... ok
[INFO] [stdout] test fifth::test::iter_mut ... ok
[INFO] [stdout] test fifth::test::miri_food ... ok
[INFO] [stdout] test fifth::test::into_iter ... ok
[INFO] [stdout] test first::basics ... ok
[INFO] [stdout] test fourth::test::into_iter ... ok
[INFO] [stdout] test fourth::test::basics ... ok
[INFO] [stdout] test fourth::test::peek ... ok
[INFO] [stdout] test second::basics ... ok
[INFO] [stdout] test second::into_iter ... ok
[INFO] [stdout] test second::peek ... ok
[INFO] [stdout] test second::iter_mut ... ok
[INFO] [stdout] test silly2::test::elegance ... ok
[INFO] [stdout] test second::iter ... ok
[INFO] [stdout] test third::test::basics ... ok
[INFO] [stdout] test third::test::iter ... ok
[INFO] [stdout] test silly2::test::cell ... ok
[INFO] [stdout] test silly1::test::walk_aboot ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 19 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.01s
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests rust_lists
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "4e2952385431f41fe22b5c34f56b946dcc2d7c0bd663e130fede6ab062b79ea1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4e2952385431f41fe22b5c34f56b946dcc2d7c0bd663e130fede6ab062b79ea1", kill_on_drop: false }`
[INFO] [stdout] 4e2952385431f41fe22b5c34f56b946dcc2d7c0bd663e130fede6ab062b79ea1
