[INFO] updating cached repository zhenhuanlee/lists
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/zhenhuanlee/lists
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/zhenhuanlee/lists" "work/ex/pr-59199/sources/master#bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7/gh/zhenhuanlee/lists"`
[INFO] [stderr] Cloning into 'work/ex/pr-59199/sources/master#bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7/gh/zhenhuanlee/lists'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/zhenhuanlee/lists" "work/ex/pr-59199/sources/try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b/gh/zhenhuanlee/lists"`
[INFO] [stderr] Cloning into 'work/ex/pr-59199/sources/try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b/gh/zhenhuanlee/lists'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 1843ceed34c5430df52e577ca11703f0eb01a3af
[INFO] sha for GitHub repo zhenhuanlee/lists: 1843ceed34c5430df52e577ca11703f0eb01a3af
[INFO] validating manifest of zhenhuanlee/lists on toolchain master#bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of zhenhuanlee/lists on toolchain try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing zhenhuanlee/lists
[INFO] finished frobbing zhenhuanlee/lists
[INFO] frobbed toml for zhenhuanlee/lists written to work/ex/pr-59199/sources/master#bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7/gh/zhenhuanlee/lists/Cargo.toml
[INFO] started frobbing zhenhuanlee/lists
[INFO] finished frobbing zhenhuanlee/lists
[INFO] frobbed toml for zhenhuanlee/lists written to work/ex/pr-59199/sources/try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b/gh/zhenhuanlee/lists/Cargo.toml
[INFO] crate zhenhuanlee/lists already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking zhenhuanlee/lists against try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b for pr-59199
[INFO] running `"docker" "create" "-v" "/mnt/crater-raid/crater/work/local/target-dirs/pr-59199/worker-6/try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b:/opt/crater/target:rw,Z" "-v" "/mnt/crater-raid/crater/work/ex/pr-59199/sources/try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b/gh/zhenhuanlee/lists:/opt/crater/workdir:ro,Z" "-v" "/mnt/crater-raid/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/crater-raid/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 46ccd542f94cc6771ef6520f7a80d1d36ad61b0a84db7d4296adb26cd9a78df0
[INFO] running `"docker" "start" "-a" "46ccd542f94cc6771ef6520f7a80d1d36ad61b0a84db7d4296adb26cd9a78df0"`
[INFO] [stderr]     Checking lists v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `super::List`
[INFO] [stderr]   --> src/lib/first.rs:56:9
[INFO] [stderr]    |
[INFO] [stderr] 56 |     use super::List;
[INFO] [stderr]    |         ^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::List`
[INFO] [stderr]    --> src/lib/second.rs:121:9
[INFO] [stderr]     |
[INFO] [stderr] 121 |     use super::List;
[INFO] [stderr]     |         ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::mem`
[INFO] [stderr]  --> src/main.rs:3:5
[INFO] [stderr]   |
[INFO] [stderr] 3 | use std::mem;
[INFO] [stderr]   |     ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::mem`
[INFO] [stderr]  --> src/main.rs:3:5
[INFO] [stderr]   |
[INFO] [stderr] 3 | use std::mem;
[INFO] [stderr]   |     ^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/main.rs:18:9
[INFO] [stderr]    |
[INFO] [stderr] 18 |     let x = iter.next().unwrap();
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `y`
[INFO] [stderr]   --> src/main.rs:19:9
[INFO] [stderr]    |
[INFO] [stderr] 19 |     let y = iter.next().unwrap();
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_y`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `z`
[INFO] [stderr]   --> src/main.rs:20:9
[INFO] [stderr]    |
[INFO] [stderr] 20 |     let z = iter.next().unwrap();
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_z`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `elem`
[INFO] [stderr]   --> src/lib/fourth.rs:28:16
[INFO] [stderr]    |
[INFO] [stderr] 28 |     pub fn new(elem: T) -> Self {
[INFO] [stderr]    |                ^^^^ help: consider prefixing with an underscore: `_elem`
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `List`
[INFO] [stderr]  --> src/lib/first.rs:4:1
[INFO] [stderr]   |
[INFO] [stderr] 4 | pub struct List {
[INFO] [stderr]   | ^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `More`
[INFO] [stderr]   --> src/lib/first.rs:11:5
[INFO] [stderr]    |
[INFO] [stderr] 11 |     More(Box<Node>),
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/lib/first.rs:22:5
[INFO] [stderr]    |
[INFO] [stderr] 22 |     pub fn new() -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `push`
[INFO] [stderr]   --> src/lib/first.rs:26:5
[INFO] [stderr]    |
[INFO] [stderr] 26 |     pub fn push(&mut self, elem: i32) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `pop`
[INFO] [stderr]   --> src/lib/first.rs:32:5
[INFO] [stderr]    |
[INFO] [stderr] 32 |     pub fn pop(&mut self) -> Option<i32> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Iter`
[INFO] [stderr]  --> src/lib/second.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub struct Iter<'a, T> {
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `IterMut`
[INFO] [stderr]  --> src/lib/second.rs:7:1
[INFO] [stderr]   |
[INFO] [stderr] 7 | pub struct IterMut<'a, T> {
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `IntoIter`
[INFO] [stderr]   --> src/lib/second.rs:12:1
[INFO] [stderr]    |
[INFO] [stderr] 12 | pub struct IntoIter<T>(List<T>);
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: type alias is never used: `Link`
[INFO] [stderr]   --> src/lib/second.rs:18:1
[INFO] [stderr]    |
[INFO] [stderr] 18 | type Link<T> = Option<Box<Node<T>>>;
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Node`
[INFO] [stderr]   --> src/lib/second.rs:20:1
[INFO] [stderr]    |
[INFO] [stderr] 20 | pub struct Node<T> {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/lib/second.rs:26:5
[INFO] [stderr]    |
[INFO] [stderr] 26 |     pub fn new() -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `push`
[INFO] [stderr]   --> src/lib/second.rs:30:5
[INFO] [stderr]    |
[INFO] [stderr] 30 |     pub fn push(&mut self, elem: T) -> &mut Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `peek`
[INFO] [stderr]   --> src/lib/second.rs:53:5
[INFO] [stderr]    |
[INFO] [stderr] 53 |     pub fn peek(&self) -> Option<&T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `mut_peek`
[INFO] [stderr]   --> src/lib/second.rs:59:5
[INFO] [stderr]    |
[INFO] [stderr] 59 |     pub fn mut_peek(&mut self) -> Option<&mut T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `into_iter`
[INFO] [stderr]   --> src/lib/second.rs:67:5
[INFO] [stderr]    |
[INFO] [stderr] 67 |     pub fn into_iter(self) -> IntoIter<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `iter`
[INFO] [stderr]   --> src/lib/second.rs:71:5
[INFO] [stderr]    |
[INFO] [stderr] 71 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `iter_mut`
[INFO] [stderr]   --> src/lib/second.rs:75:5
[INFO] [stderr]    |
[INFO] [stderr] 75 |     pub fn iter_mut(&mut self) -> IterMut<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `List`
[INFO] [stderr]  --> src/lib/third.rs:4:2
[INFO] [stderr]   |
[INFO] [stderr] 4 |  pub struct List<T> {
[INFO] [stderr]   |  ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: type alias is never used: `Link`
[INFO] [stderr]  --> src/lib/third.rs:8:1
[INFO] [stderr]   |
[INFO] [stderr] 8 | type Link<T> = Option<Rc<Node<T>>>;
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Node`
[INFO] [stderr]   --> src/lib/third.rs:11:1
[INFO] [stderr]    |
[INFO] [stderr] 11 | pub struct Node<T> {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Iter`
[INFO] [stderr]   --> src/lib/third.rs:16:1
[INFO] [stderr]    |
[INFO] [stderr] 16 | pub struct Iter<'a, T> {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `iter`
[INFO] [stderr]   --> src/lib/third.rs:21:5
[INFO] [stderr]    |
[INFO] [stderr] 21 |     fn iter(&self) -> Iter<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/lib/third.rs:38:5
[INFO] [stderr]    |
[INFO] [stderr] 38 |     pub fn new() -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `append`
[INFO] [stderr]   --> src/lib/third.rs:42:5
[INFO] [stderr]    |
[INFO] [stderr] 42 |     pub fn append(&self, elem: T) -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `tail`
[INFO] [stderr]   --> src/lib/third.rs:56:5
[INFO] [stderr]    |
[INFO] [stderr] 56 |     pub fn tail(&self) -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `head`
[INFO] [stderr]   --> src/lib/third.rs:60:5
[INFO] [stderr]    |
[INFO] [stderr] 60 |     pub fn head(&self) -> Option<&T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `List`
[INFO] [stderr]  --> src/lib/fourth.rs:4:1
[INFO] [stderr]   |
[INFO] [stderr] 4 | struct List<T> {
[INFO] [stderr]   | ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: type alias is never used: `Link`
[INFO] [stderr]  --> src/lib/fourth.rs:9:1
[INFO] [stderr]   |
[INFO] [stderr] 9 | type Link<T> = Option<Rc<RefCell<Node<T>>>>;
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Node`
[INFO] [stderr]   --> src/lib/fourth.rs:11:1
[INFO] [stderr]    |
[INFO] [stderr] 11 | struct Node<T> {
[INFO] [stderr]    | ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/lib/fourth.rs:18:5
[INFO] [stderr]    |
[INFO] [stderr] 18 |     fn new(elem: T) -> Rc<RefCell<Self>> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/lib/fourth.rs:28:5
[INFO] [stderr]    |
[INFO] [stderr] 28 |     pub fn new(elem: T) -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `push_front`
[INFO] [stderr]   --> src/lib/fourth.rs:32:5
[INFO] [stderr]    |
[INFO] [stderr] 32 |     pub fn push_front(&mut self, elem: T) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `second`
[INFO] [stderr]   --> src/main.rs:13:1
[INFO] [stderr]    |
[INFO] [stderr] 13 | fn second() {
[INFO] [stderr]    | ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `first`
[INFO] [stderr]   --> src/main.rs:23:1
[INFO] [stderr]    |
[INFO] [stderr] 23 | fn first() {
[INFO] [stderr]    | ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `test_ref`
[INFO] [stderr]   --> src/main.rs:39:1
[INFO] [stderr]    |
[INFO] [stderr] 39 | fn test_ref() {
[INFO] [stderr]    | ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/main.rs:18:9
[INFO] [stderr]    |
[INFO] [stderr] 18 |     let x = iter.next().unwrap();
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `y`
[INFO] [stderr]   --> src/main.rs:19:9
[INFO] [stderr]    |
[INFO] [stderr] 19 |     let y = iter.next().unwrap();
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_y`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `z`
[INFO] [stderr]   --> src/main.rs:20:9
[INFO] [stderr]    |
[INFO] [stderr] 20 |     let z = iter.next().unwrap();
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_z`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `elem`
[INFO] [stderr]   --> src/lib/fourth.rs:28:16
[INFO] [stderr]    |
[INFO] [stderr] 28 |     pub fn new(elem: T) -> Self {
[INFO] [stderr]    |                ^^^^ help: consider prefixing with an underscore: `_elem`
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `List`
[INFO] [stderr]  --> src/lib/fourth.rs:4:1
[INFO] [stderr]   |
[INFO] [stderr] 4 | struct List<T> {
[INFO] [stderr]   | ^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: type alias is never used: `Link`
[INFO] [stderr]  --> src/lib/fourth.rs:9:1
[INFO] [stderr]   |
[INFO] [stderr] 9 | type Link<T> = Option<Rc<RefCell<Node<T>>>>;
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Node`
[INFO] [stderr]   --> src/lib/fourth.rs:11:1
[INFO] [stderr]    |
[INFO] [stderr] 11 | struct Node<T> {
[INFO] [stderr]    | ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/lib/fourth.rs:18:5
[INFO] [stderr]    |
[INFO] [stderr] 18 |     fn new(elem: T) -> Rc<RefCell<Self>> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/lib/fourth.rs:28:5
[INFO] [stderr]    |
[INFO] [stderr] 28 |     pub fn new(elem: T) -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `push_front`
[INFO] [stderr]   --> src/lib/fourth.rs:32:5
[INFO] [stderr]    |
[INFO] [stderr] 32 |     pub fn push_front(&mut self, elem: T) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `second`
[INFO] [stderr]   --> src/main.rs:13:1
[INFO] [stderr]    |
[INFO] [stderr] 13 | fn second() {
[INFO] [stderr]    | ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `first`
[INFO] [stderr]   --> src/main.rs:23:1
[INFO] [stderr]    |
[INFO] [stderr] 23 | fn first() {
[INFO] [stderr]    | ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `test_ref`
[INFO] [stderr]   --> src/main.rs:39:1
[INFO] [stderr]    |
[INFO] [stderr] 39 | fn test_ref() {
[INFO] [stderr]    | ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.70s
[INFO] running `"docker" "inspect" "46ccd542f94cc6771ef6520f7a80d1d36ad61b0a84db7d4296adb26cd9a78df0"`
[INFO] running `"docker" "rm" "-f" "46ccd542f94cc6771ef6520f7a80d1d36ad61b0a84db7d4296adb26cd9a78df0"`
[INFO] [stdout] 46ccd542f94cc6771ef6520f7a80d1d36ad61b0a84db7d4296adb26cd9a78df0