Dec 17 10:55:59.141 INFO checking zhenhuanlee/lists against master#96d1334e567237b1507cd277938e7ae2de75ff51 for pr-54252
Dec 17 10:55:59.141 INFO running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-54252/worker-3/master#96d1334e567237b1507cd277938e7ae2de75ff51:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-54252/sources/master#96d1334e567237b1507cd277938e7ae2de75ff51/gh/zhenhuanlee/lists:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/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" "+96d1334e567237b1507cd277938e7ae2de75ff51-alt" "check" "--frozen" "--all" "--all-targets"`
Dec 17 10:55:59.356 INFO [stdout] 6d0263e79635e9d226b9dbd1ceed7742580ac5e03e13caf24c79e388905765f1
Dec 17 10:55:59.358 INFO running `"docker" "start" "-a" "6d0263e79635e9d226b9dbd1ceed7742580ac5e03e13caf24c79e388905765f1"`
Dec 17 10:56:00.116 INFO [stderr]     Checking lists v0.1.0 (/opt/crater/workdir)
Dec 17 10:56:00.284 INFO [stderr] warning: unused import: `std::mem`
Dec 17 10:56:00.284 INFO [stderr]  --> src/main.rs:3:5
Dec 17 10:56:00.284 INFO [stderr]   |
Dec 17 10:56:00.284 INFO [stderr] 3 | use std::mem;
Dec 17 10:56:00.284 INFO [stderr]   |     ^^^^^^^^
Dec 17 10:56:00.284 INFO [stderr]   |
Dec 17 10:56:00.284 INFO [stderr]   = note: #[warn(unused_imports)] on by default
Dec 17 10:56:00.284 INFO [stderr] 
Dec 17 10:56:00.306 INFO [stderr] warning: unused import: `super::List`
Dec 17 10:56:00.306 INFO [stderr]   --> src/lib/first.rs:56:9
Dec 17 10:56:00.306 INFO [stderr]    |
Dec 17 10:56:00.306 INFO [stderr] 56 |     use super::List;
Dec 17 10:56:00.306 INFO [stderr]    |         ^^^^^^^^^^^
Dec 17 10:56:00.306 INFO [stderr]    |
Dec 17 10:56:00.306 INFO [stderr]    = note: #[warn(unused_imports)] on by default
Dec 17 10:56:00.306 INFO [stderr] 
Dec 17 10:56:00.306 INFO [stderr] warning: unused import: `super::List`
Dec 17 10:56:00.306 INFO [stderr]    --> src/lib/second.rs:121:9
Dec 17 10:56:00.306 INFO [stderr]     |
Dec 17 10:56:00.306 INFO [stderr] 121 |     use super::List;
Dec 17 10:56:00.306 INFO [stderr]     |         ^^^^^^^^^^^
Dec 17 10:56:00.306 INFO [stderr] 
Dec 17 10:56:00.306 INFO [stderr] warning: unused import: `std::mem`
Dec 17 10:56:00.306 INFO [stderr]  --> src/main.rs:3:5
Dec 17 10:56:00.307 INFO [stderr]   |
Dec 17 10:56:00.307 INFO [stderr] 3 | use std::mem;
Dec 17 10:56:00.307 INFO [stderr]   |     ^^^^^^^^
Dec 17 10:56:00.307 INFO [stderr] 
Dec 17 10:56:00.488 INFO [stderr] warning: unused variable: `x`
Dec 17 10:56:00.488 INFO [stderr]   --> src/main.rs:18:9
Dec 17 10:56:00.488 INFO [stderr]    |
Dec 17 10:56:00.488 INFO [stderr] 18 |     let x = iter.next().unwrap();
Dec 17 10:56:00.488 INFO [stderr]    |         ^ help: consider using `_x` instead
Dec 17 10:56:00.488 INFO [stderr]    |
Dec 17 10:56:00.488 INFO [stderr]    = note: #[warn(unused_variables)] on by default
Dec 17 10:56:00.488 INFO [stderr] 
Dec 17 10:56:00.488 INFO [stderr] warning: unused variable: `y`
Dec 17 10:56:00.488 INFO [stderr]   --> src/main.rs:19:9
Dec 17 10:56:00.488 INFO [stderr]    |
Dec 17 10:56:00.488 INFO [stderr] 19 |     let y = iter.next().unwrap();
Dec 17 10:56:00.488 INFO [stderr]    |         ^ help: consider using `_y` instead
Dec 17 10:56:00.488 INFO [stderr] 
Dec 17 10:56:00.488 INFO [stderr] warning: unused variable: `z`
Dec 17 10:56:00.488 INFO [stderr]   --> src/main.rs:20:9
Dec 17 10:56:00.488 INFO [stderr]    |
Dec 17 10:56:00.489 INFO [stderr] 20 |     let z = iter.next().unwrap();
Dec 17 10:56:00.489 INFO [stderr]    |         ^ help: consider using `_z` instead
Dec 17 10:56:00.489 INFO [stderr] 
Dec 17 10:56:00.489 INFO [stderr] warning: unused variable: `elem`
Dec 17 10:56:00.489 INFO [stderr]   --> src/lib/fourth.rs:28:16
Dec 17 10:56:00.489 INFO [stderr]    |
Dec 17 10:56:00.489 INFO [stderr] 28 |     pub fn new(elem: T) -> Self {
Dec 17 10:56:00.489 INFO [stderr]    |                ^^^^ help: consider using `_elem` instead
Dec 17 10:56:00.489 INFO [stderr] 
Dec 17 10:56:00.549 INFO [stderr] warning: struct is never constructed: `List`
Dec 17 10:56:00.549 INFO [stderr]  --> src/lib/first.rs:4:1
Dec 17 10:56:00.549 INFO [stderr]   |
Dec 17 10:56:00.549 INFO [stderr] 4 | pub struct List {
Dec 17 10:56:00.549 INFO [stderr]   | ^^^^^^^^^^^^^^^
Dec 17 10:56:00.549 INFO [stderr]   |
Dec 17 10:56:00.549 INFO [stderr]   = note: #[warn(dead_code)] on by default
Dec 17 10:56:00.549 INFO [stderr] 
Dec 17 10:56:00.549 INFO [stderr] warning: variant is never constructed: `More`
Dec 17 10:56:00.549 INFO [stderr]   --> src/lib/first.rs:11:5
Dec 17 10:56:00.549 INFO [stderr]    |
Dec 17 10:56:00.549 INFO [stderr] 11 |     More(Box<Node>),
Dec 17 10:56:00.549 INFO [stderr]    |     ^^^^^^^^^^^^^^^
Dec 17 10:56:00.549 INFO [stderr] 
Dec 17 10:56:00.549 INFO [stderr] warning: method is never used: `new`
Dec 17 10:56:00.549 INFO [stderr]   --> src/lib/first.rs:22:5
Dec 17 10:56:00.549 INFO [stderr]    |
Dec 17 10:56:00.549 INFO [stderr] 22 |     pub fn new() -> Self {
Dec 17 10:56:00.549 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.549 INFO [stderr] 
Dec 17 10:56:00.549 INFO [stderr] warning: method is never used: `push`
Dec 17 10:56:00.549 INFO [stderr]   --> src/lib/first.rs:26:5
Dec 17 10:56:00.549 INFO [stderr]    |
Dec 17 10:56:00.549 INFO [stderr] 26 |     pub fn push(&mut self, elem: i32) {
Dec 17 10:56:00.549 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.549 INFO [stderr] 
Dec 17 10:56:00.549 INFO [stderr] warning: method is never used: `pop`
Dec 17 10:56:00.549 INFO [stderr]   --> src/lib/first.rs:32:5
Dec 17 10:56:00.549 INFO [stderr]    |
Dec 17 10:56:00.549 INFO [stderr] 32 |     pub fn pop(&mut self) -> Option<i32> {
Dec 17 10:56:00.549 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.549 INFO [stderr] 
Dec 17 10:56:00.549 INFO [stderr] warning: struct is never constructed: `Iter`
Dec 17 10:56:00.549 INFO [stderr]  --> src/lib/second.rs:3:1
Dec 17 10:56:00.549 INFO [stderr]   |
Dec 17 10:56:00.549 INFO [stderr] 3 | pub struct Iter<'a, T> {
Dec 17 10:56:00.549 INFO [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.549 INFO [stderr] 
Dec 17 10:56:00.549 INFO [stderr] warning: struct is never constructed: `IterMut`
Dec 17 10:56:00.549 INFO [stderr]  --> src/lib/second.rs:7:1
Dec 17 10:56:00.549 INFO [stderr]   |
Dec 17 10:56:00.549 INFO [stderr] 7 | pub struct IterMut<'a, T> {
Dec 17 10:56:00.549 INFO [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.549 INFO [stderr] 
Dec 17 10:56:00.549 INFO [stderr] warning: struct is never constructed: `IntoIter`
Dec 17 10:56:00.549 INFO [stderr]   --> src/lib/second.rs:12:1
Dec 17 10:56:00.549 INFO [stderr]    |
Dec 17 10:56:00.549 INFO [stderr] 12 | pub struct IntoIter<T>(List<T>);
Dec 17 10:56:00.549 INFO [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.549 INFO [stderr] 
Dec 17 10:56:00.549 INFO [stderr] warning: type alias is never used: `Link`
Dec 17 10:56:00.549 INFO [stderr]   --> src/lib/second.rs:18:1
Dec 17 10:56:00.549 INFO [stderr]    |
Dec 17 10:56:00.549 INFO [stderr] 18 | type Link<T> = Option<Box<Node<T>>>;
Dec 17 10:56:00.549 INFO [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.549 INFO [stderr] 
Dec 17 10:56:00.549 INFO [stderr] warning: struct is never constructed: `Node`
Dec 17 10:56:00.549 INFO [stderr]   --> src/lib/second.rs:20:1
Dec 17 10:56:00.549 INFO [stderr]    |
Dec 17 10:56:00.549 INFO [stderr] 20 | pub struct Node<T> {
Dec 17 10:56:00.549 INFO [stderr]    | ^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.549 INFO [stderr] 
Dec 17 10:56:00.549 INFO [stderr] warning: method is never used: `new`
Dec 17 10:56:00.549 INFO [stderr]   --> src/lib/second.rs:26:5
Dec 17 10:56:00.549 INFO [stderr]    |
Dec 17 10:56:00.549 INFO [stderr] 26 |     pub fn new() -> Self {
Dec 17 10:56:00.549 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.549 INFO [stderr] 
Dec 17 10:56:00.549 INFO [stderr] warning: method is never used: `push`
Dec 17 10:56:00.549 INFO [stderr]   --> src/lib/second.rs:30:5
Dec 17 10:56:00.549 INFO [stderr]    |
Dec 17 10:56:00.549 INFO [stderr] 30 |     pub fn push(&mut self, elem: T) -> &mut Self {
Dec 17 10:56:00.549 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.549 INFO [stderr] 
Dec 17 10:56:00.549 INFO [stderr] warning: method is never used: `peek`
Dec 17 10:56:00.549 INFO [stderr]   --> src/lib/second.rs:53:5
Dec 17 10:56:00.549 INFO [stderr]    |
Dec 17 10:56:00.549 INFO [stderr] 53 |     pub fn peek(&self) -> Option<&T> {
Dec 17 10:56:00.549 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.549 INFO [stderr] 
Dec 17 10:56:00.550 INFO [stderr] warning: method is never used: `mut_peek`
Dec 17 10:56:00.550 INFO [stderr]   --> src/lib/second.rs:59:5
Dec 17 10:56:00.550 INFO [stderr]    |
Dec 17 10:56:00.550 INFO [stderr] 59 |     pub fn mut_peek(&mut self) -> Option<&mut T> {
Dec 17 10:56:00.550 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.550 INFO [stderr] 
Dec 17 10:56:00.550 INFO [stderr] warning: method is never used: `into_iter`
Dec 17 10:56:00.550 INFO [stderr]   --> src/lib/second.rs:67:5
Dec 17 10:56:00.550 INFO [stderr]    |
Dec 17 10:56:00.550 INFO [stderr] 67 |     pub fn into_iter(self) -> IntoIter<T> {
Dec 17 10:56:00.550 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.550 INFO [stderr] 
Dec 17 10:56:00.550 INFO [stderr] warning: method is never used: `iter`
Dec 17 10:56:00.550 INFO [stderr]   --> src/lib/second.rs:71:5
Dec 17 10:56:00.550 INFO [stderr]    |
Dec 17 10:56:00.550 INFO [stderr] 71 |     pub fn iter(&self) -> Iter<T> {
Dec 17 10:56:00.550 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.550 INFO [stderr] 
Dec 17 10:56:00.550 INFO [stderr] warning: method is never used: `iter_mut`
Dec 17 10:56:00.550 INFO [stderr]   --> src/lib/second.rs:75:5
Dec 17 10:56:00.550 INFO [stderr]    |
Dec 17 10:56:00.550 INFO [stderr] 75 |     pub fn iter_mut(&mut self) -> IterMut<T> {
Dec 17 10:56:00.550 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.550 INFO [stderr] 
Dec 17 10:56:00.550 INFO [stderr] warning: struct is never constructed: `List`
Dec 17 10:56:00.550 INFO [stderr]  --> src/lib/third.rs:4:2
Dec 17 10:56:00.550 INFO [stderr]   |
Dec 17 10:56:00.550 INFO [stderr] 4 |  pub struct List<T> {
Dec 17 10:56:00.550 INFO [stderr]   |  ^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.550 INFO [stderr] 
Dec 17 10:56:00.550 INFO [stderr] warning: type alias is never used: `Link`
Dec 17 10:56:00.550 INFO [stderr]  --> src/lib/third.rs:8:1
Dec 17 10:56:00.550 INFO [stderr]   |
Dec 17 10:56:00.550 INFO [stderr] 8 | type Link<T> = Option<Rc<Node<T>>>;
Dec 17 10:56:00.550 INFO [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.550 INFO [stderr] 
Dec 17 10:56:00.550 INFO [stderr] warning: struct is never constructed: `Node`
Dec 17 10:56:00.550 INFO [stderr]   --> src/lib/third.rs:11:1
Dec 17 10:56:00.550 INFO [stderr]    |
Dec 17 10:56:00.550 INFO [stderr] 11 | pub struct Node<T> {
Dec 17 10:56:00.550 INFO [stderr]    | ^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.550 INFO [stderr] 
Dec 17 10:56:00.550 INFO [stderr] warning: struct is never constructed: `Iter`
Dec 17 10:56:00.550 INFO [stderr]   --> src/lib/third.rs:16:1
Dec 17 10:56:00.550 INFO [stderr]    |
Dec 17 10:56:00.550 INFO [stderr] 16 | pub struct Iter<'a, T> {
Dec 17 10:56:00.550 INFO [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.551 INFO [stderr] 
Dec 17 10:56:00.551 INFO [stderr] warning: method is never used: `iter`
Dec 17 10:56:00.551 INFO [stderr]   --> src/lib/third.rs:21:5
Dec 17 10:56:00.551 INFO [stderr]    |
Dec 17 10:56:00.551 INFO [stderr] 21 |     fn iter(&self) -> Iter<T> {
Dec 17 10:56:00.551 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.551 INFO [stderr] 
Dec 17 10:56:00.551 INFO [stderr] warning: method is never used: `new`
Dec 17 10:56:00.551 INFO [stderr]   --> src/lib/third.rs:38:5
Dec 17 10:56:00.551 INFO [stderr]    |
Dec 17 10:56:00.551 INFO [stderr] 38 |     pub fn new() -> Self {
Dec 17 10:56:00.551 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.551 INFO [stderr] 
Dec 17 10:56:00.551 INFO [stderr] warning: method is never used: `append`
Dec 17 10:56:00.551 INFO [stderr]   --> src/lib/third.rs:42:5
Dec 17 10:56:00.551 INFO [stderr]    |
Dec 17 10:56:00.551 INFO [stderr] 42 |     pub fn append(&self, elem: T) -> Self {
Dec 17 10:56:00.551 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.551 INFO [stderr] 
Dec 17 10:56:00.551 INFO [stderr] warning: method is never used: `tail`
Dec 17 10:56:00.551 INFO [stderr]   --> src/lib/third.rs:56:5
Dec 17 10:56:00.551 INFO [stderr]    |
Dec 17 10:56:00.551 INFO [stderr] 56 |     pub fn tail(&self) -> Self {
Dec 17 10:56:00.551 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.551 INFO [stderr] 
Dec 17 10:56:00.551 INFO [stderr] warning: method is never used: `head`
Dec 17 10:56:00.551 INFO [stderr]   --> src/lib/third.rs:60:5
Dec 17 10:56:00.551 INFO [stderr]    |
Dec 17 10:56:00.551 INFO [stderr] 60 |     pub fn head(&self) -> Option<&T> {
Dec 17 10:56:00.551 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.551 INFO [stderr] 
Dec 17 10:56:00.551 INFO [stderr] warning: struct is never constructed: `List`
Dec 17 10:56:00.551 INFO [stderr]  --> src/lib/fourth.rs:4:1
Dec 17 10:56:00.551 INFO [stderr]   |
Dec 17 10:56:00.551 INFO [stderr] 4 | struct List<T> {
Dec 17 10:56:00.551 INFO [stderr]   | ^^^^^^^^^^^^^^
Dec 17 10:56:00.552 INFO [stderr] 
Dec 17 10:56:00.552 INFO [stderr] warning: type alias is never used: `Link`
Dec 17 10:56:00.552 INFO [stderr]  --> src/lib/fourth.rs:9:1
Dec 17 10:56:00.552 INFO [stderr]   |
Dec 17 10:56:00.552 INFO [stderr] 9 | type Link<T> = Option<Rc<RefCell<Node<T>>>>;
Dec 17 10:56:00.552 INFO [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.552 INFO [stderr] 
Dec 17 10:56:00.552 INFO [stderr] warning: struct is never constructed: `Node`
Dec 17 10:56:00.552 INFO [stderr]   --> src/lib/fourth.rs:11:1
Dec 17 10:56:00.552 INFO [stderr]    |
Dec 17 10:56:00.552 INFO [stderr] 11 | struct Node<T> {
Dec 17 10:56:00.552 INFO [stderr]    | ^^^^^^^^^^^^^^
Dec 17 10:56:00.552 INFO [stderr] 
Dec 17 10:56:00.552 INFO [stderr] warning: method is never used: `new`
Dec 17 10:56:00.552 INFO [stderr]   --> src/lib/fourth.rs:18:5
Dec 17 10:56:00.552 INFO [stderr]    |
Dec 17 10:56:00.552 INFO [stderr] 18 |     fn new(elem: T) -> Rc<RefCell<Self>> {
Dec 17 10:56:00.552 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.552 INFO [stderr] 
Dec 17 10:56:00.552 INFO [stderr] warning: method is never used: `new`
Dec 17 10:56:00.552 INFO [stderr]   --> src/lib/fourth.rs:28:5
Dec 17 10:56:00.552 INFO [stderr]    |
Dec 17 10:56:00.552 INFO [stderr] 28 |     pub fn new(elem: T) -> Self {
Dec 17 10:56:00.552 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.552 INFO [stderr] 
Dec 17 10:56:00.552 INFO [stderr] warning: method is never used: `push_front`
Dec 17 10:56:00.552 INFO [stderr]   --> src/lib/fourth.rs:32:5
Dec 17 10:56:00.553 INFO [stderr]    |
Dec 17 10:56:00.553 INFO [stderr] 32 |     pub fn push_front(&mut self, elem: T) {
Dec 17 10:56:00.553 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.553 INFO [stderr] 
Dec 17 10:56:00.553 INFO [stderr] warning: function is never used: `second`
Dec 17 10:56:00.553 INFO [stderr]   --> src/main.rs:13:1
Dec 17 10:56:00.553 INFO [stderr]    |
Dec 17 10:56:00.553 INFO [stderr] 13 | fn second() {
Dec 17 10:56:00.553 INFO [stderr]    | ^^^^^^^^^^^
Dec 17 10:56:00.556 INFO [stderr] 
Dec 17 10:56:00.556 INFO [stderr] warning: function is never used: `first`
Dec 17 10:56:00.556 INFO [stderr]   --> src/main.rs:23:1
Dec 17 10:56:00.556 INFO [stderr]    |
Dec 17 10:56:00.556 INFO [stderr] 23 | fn first() {
Dec 17 10:56:00.556 INFO [stderr]    | ^^^^^^^^^^
Dec 17 10:56:00.556 INFO [stderr] 
Dec 17 10:56:00.556 INFO [stderr] warning: function is never used: `test_ref`
Dec 17 10:56:00.556 INFO [stderr]   --> src/main.rs:39:1
Dec 17 10:56:00.556 INFO [stderr]    |
Dec 17 10:56:00.556 INFO [stderr] 39 | fn test_ref() {
Dec 17 10:56:00.556 INFO [stderr]    | ^^^^^^^^^^^^^
Dec 17 10:56:00.556 INFO [stderr] 
Dec 17 10:56:00.628 INFO [stderr] warning: unused variable: `x`
Dec 17 10:56:00.628 INFO [stderr]   --> src/main.rs:18:9
Dec 17 10:56:00.628 INFO [stderr]    |
Dec 17 10:56:00.628 INFO [stderr] 18 |     let x = iter.next().unwrap();
Dec 17 10:56:00.628 INFO [stderr]    |         ^ help: consider using `_x` instead
Dec 17 10:56:00.628 INFO [stderr]    |
Dec 17 10:56:00.628 INFO [stderr]    = note: #[warn(unused_variables)] on by default
Dec 17 10:56:00.628 INFO [stderr] 
Dec 17 10:56:00.628 INFO [stderr] warning: unused variable: `y`
Dec 17 10:56:00.628 INFO [stderr]   --> src/main.rs:19:9
Dec 17 10:56:00.628 INFO [stderr]    |
Dec 17 10:56:00.628 INFO [stderr] 19 |     let y = iter.next().unwrap();
Dec 17 10:56:00.628 INFO [stderr]    |         ^ help: consider using `_y` instead
Dec 17 10:56:00.628 INFO [stderr] 
Dec 17 10:56:00.628 INFO [stderr] warning: unused variable: `z`
Dec 17 10:56:00.628 INFO [stderr]   --> src/main.rs:20:9
Dec 17 10:56:00.628 INFO [stderr]    |
Dec 17 10:56:00.628 INFO [stderr] 20 |     let z = iter.next().unwrap();
Dec 17 10:56:00.628 INFO [stderr]    |         ^ help: consider using `_z` instead
Dec 17 10:56:00.628 INFO [stderr] 
Dec 17 10:56:00.636 INFO [stderr] warning: unused variable: `elem`
Dec 17 10:56:00.636 INFO [stderr]   --> src/lib/fourth.rs:28:16
Dec 17 10:56:00.636 INFO [stderr]    |
Dec 17 10:56:00.636 INFO [stderr] 28 |     pub fn new(elem: T) -> Self {
Dec 17 10:56:00.636 INFO [stderr]    |                ^^^^ help: consider using `_elem` instead
Dec 17 10:56:00.636 INFO [stderr] 
Dec 17 10:56:00.727 INFO [stderr] warning: struct is never constructed: `List`
Dec 17 10:56:00.727 INFO [stderr]  --> src/lib/fourth.rs:4:1
Dec 17 10:56:00.727 INFO [stderr]   |
Dec 17 10:56:00.727 INFO [stderr] 4 | struct List<T> {
Dec 17 10:56:00.727 INFO [stderr]   | ^^^^^^^^^^^^^^
Dec 17 10:56:00.727 INFO [stderr]   |
Dec 17 10:56:00.727 INFO [stderr]   = note: #[warn(dead_code)] on by default
Dec 17 10:56:00.727 INFO [stderr] 
Dec 17 10:56:00.727 INFO [stderr] warning: type alias is never used: `Link`
Dec 17 10:56:00.727 INFO [stderr]  --> src/lib/fourth.rs:9:1
Dec 17 10:56:00.727 INFO [stderr]   |
Dec 17 10:56:00.727 INFO [stderr] 9 | type Link<T> = Option<Rc<RefCell<Node<T>>>>;
Dec 17 10:56:00.727 INFO [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.727 INFO [stderr] 
Dec 17 10:56:00.727 INFO [stderr] warning: struct is never constructed: `Node`
Dec 17 10:56:00.727 INFO [stderr]   --> src/lib/fourth.rs:11:1
Dec 17 10:56:00.727 INFO [stderr]    |
Dec 17 10:56:00.727 INFO [stderr] 11 | struct Node<T> {
Dec 17 10:56:00.727 INFO [stderr]    | ^^^^^^^^^^^^^^
Dec 17 10:56:00.727 INFO [stderr] 
Dec 17 10:56:00.727 INFO [stderr] warning: method is never used: `new`
Dec 17 10:56:00.727 INFO [stderr]   --> src/lib/fourth.rs:18:5
Dec 17 10:56:00.727 INFO [stderr]    |
Dec 17 10:56:00.727 INFO [stderr] 18 |     fn new(elem: T) -> Rc<RefCell<Self>> {
Dec 17 10:56:00.727 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.727 INFO [stderr] 
Dec 17 10:56:00.727 INFO [stderr] warning: method is never used: `new`
Dec 17 10:56:00.727 INFO [stderr]   --> src/lib/fourth.rs:28:5
Dec 17 10:56:00.727 INFO [stderr]    |
Dec 17 10:56:00.727 INFO [stderr] 28 |     pub fn new(elem: T) -> Self {
Dec 17 10:56:00.727 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.727 INFO [stderr] 
Dec 17 10:56:00.727 INFO [stderr] warning: method is never used: `push_front`
Dec 17 10:56:00.727 INFO [stderr]   --> src/lib/fourth.rs:32:5
Dec 17 10:56:00.727 INFO [stderr]    |
Dec 17 10:56:00.727 INFO [stderr] 32 |     pub fn push_front(&mut self, elem: T) {
Dec 17 10:56:00.727 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 17 10:56:00.727 INFO [stderr] 
Dec 17 10:56:00.727 INFO [stderr] warning: function is never used: `second`
Dec 17 10:56:00.727 INFO [stderr]   --> src/main.rs:13:1
Dec 17 10:56:00.727 INFO [stderr]    |
Dec 17 10:56:00.727 INFO [stderr] 13 | fn second() {
Dec 17 10:56:00.727 INFO [stderr]    | ^^^^^^^^^^^
Dec 17 10:56:00.727 INFO [stderr] 
Dec 17 10:56:00.727 INFO [stderr] warning: function is never used: `first`
Dec 17 10:56:00.727 INFO [stderr]   --> src/main.rs:23:1
Dec 17 10:56:00.727 INFO [stderr]    |
Dec 17 10:56:00.727 INFO [stderr] 23 | fn first() {
Dec 17 10:56:00.727 INFO [stderr]    | ^^^^^^^^^^
Dec 17 10:56:00.727 INFO [stderr] 
Dec 17 10:56:00.727 INFO [stderr] warning: function is never used: `test_ref`
Dec 17 10:56:00.727 INFO [stderr]   --> src/main.rs:39:1
Dec 17 10:56:00.727 INFO [stderr]    |
Dec 17 10:56:00.727 INFO [stderr] 39 | fn test_ref() {
Dec 17 10:56:00.727 INFO [stderr]    | ^^^^^^^^^^^^^
Dec 17 10:56:00.727 INFO [stderr] 
Dec 17 10:56:00.754 INFO [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.65s
Dec 17 10:56:01.550 INFO running `"docker" "inspect" "6d0263e79635e9d226b9dbd1ceed7742580ac5e03e13caf24c79e388905765f1"`
Dec 17 10:56:01.784 INFO running `"docker" "rm" "-f" "6d0263e79635e9d226b9dbd1ceed7742580ac5e03e13caf24c79e388905765f1"`
Dec 17 10:56:02.028 INFO [stdout] 6d0263e79635e9d226b9dbd1ceed7742580ac5e03e13caf24c79e388905765f1