[INFO] updating cached repository https://github.com/VladADragos/rust_sandbox
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 542df2b3bf7e7a72f61f2ed4966321ac802095ab
[INFO] testing VladADragos/rust_sandbox against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FVladADragos%2Frust_sandbox" "/workspace/builds/worker-92/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-92/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/VladADragos/rust_sandbox on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/VladADragos/rust_sandbox
[INFO] finished tweaking git repo https://github.com/VladADragos/rust_sandbox
[INFO] tweaked toml for git repo https://github.com/VladADragos/rust_sandbox written to /workspace/builds/worker-92/source/Cargo.toml
[INFO] crate git repo https://github.com/VladADragos/rust_sandbox already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-92/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-92/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2cadcb1cbb074a5463c6acccdca3c51ce7174fa7cca1dd9d4ef3c29163da3192
[INFO] running `Command { std: "docker" "start" "-a" "2cadcb1cbb074a5463c6acccdca3c51ce7174fa7cca1dd9d4ef3c29163da3192", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2cadcb1cbb074a5463c6acccdca3c51ce7174fa7cca1dd9d4ef3c29163da3192", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2cadcb1cbb074a5463c6acccdca3c51ce7174fa7cca1dd9d4ef3c29163da3192", kill_on_drop: false }`
[INFO] [stdout] 2cadcb1cbb074a5463c6acccdca3c51ce7174fa7cca1dd9d4ef3c29163da3192
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-92/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-92/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] da244b7faae71239dc936a947250bbd08296c86cba30382ac747fa37b888f953
[INFO] running `Command { std: "docker" "start" "-a" "da244b7faae71239dc936a947250bbd08296c86cba30382ac747fa37b888f953", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.66
[INFO] [stderr]    Compiling rand_core v0.4.2
[INFO] [stderr]    Compiling rand_core v0.3.1
[INFO] [stderr]    Compiling rand v0.5.6
[INFO] [stderr]    Compiling exercises v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::collections::binary_heap`
[INFO] [stdout]  --> src/main.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::collections::binary_heap;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cmp::Ordering`
[INFO] [stdout]  --> src/heaps/heap.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cmp::Ordering;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `test_mat`
[INFO] [stdout]  --> src/mat.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn test_mat() {
[INFO] [stdout]   |        ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `det`
[INFO] [stdout]  --> src/mat.rs:7:4
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn det(mat: &[[f64; 3]; 3]) -> f64 {
[INFO] [stdout]   |    ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `is_sorted`
[INFO] [stdout]  --> src/sorting/is_sorted.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn is_sorted<T: PartialOrd>(arr: &[T]) -> bool {
[INFO] [stdout]   |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> src/heaps/comparator.rs:11:12
[INFO] [stdout]    |
[INFO] [stdout] 11 |     pub fn new() -> MinComparator {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `is_equal`
[INFO] [stdout]   --> src/heaps/comparator.rs:22:12
[INFO] [stdout]    |
[INFO] [stdout] 22 |     pub fn is_equal(self) -> bool {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `is_less`
[INFO] [stdout]   --> src/heaps/comparator.rs:34:12
[INFO] [stdout]    |
[INFO] [stdout] 34 |     pub fn is_less(self) -> bool {
[INFO] [stdout]    |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `unwrap`
[INFO] [stdout]   --> src/heaps/comparator.rs:40:12
[INFO] [stdout]    |
[INFO] [stdout] 40 |     pub fn unwrap(self) -> Ordering {
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `len`
[INFO] [stdout]   --> src/heaps/heap.rs:37:12
[INFO] [stdout]    |
[INFO] [stdout] 37 |     pub fn len(self) -> usize {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `peak`
[INFO] [stdout]   --> src/heaps/heap.rs:40:12
[INFO] [stdout]    |
[INFO] [stdout] 40 |     pub fn peak(self) -> Option<T> {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `remove_root`
[INFO] [stdout]   --> src/heaps/heap.rs:47:12
[INFO] [stdout]    |
[INFO] [stdout] 47 |     pub fn remove_root(&mut self) -> Option<T> {
[INFO] [stdout]    |            ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `sift_down`
[INFO] [stdout]   --> src/heaps/heap.rs:83:8
[INFO] [stdout]    |
[INFO] [stdout] 83 |     fn sift_down(&mut self, i: usize) {
[INFO] [stdout]    |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `get_right_child`
[INFO] [stdout]    --> src/heaps/heap.rs:120:4
[INFO] [stdout]     |
[INFO] [stdout] 120 | fn get_right_child(i: usize) -> usize {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `get_left_child`
[INFO] [stdout]    --> src/heaps/heap.rs:123:4
[INFO] [stdout]     |
[INFO] [stdout] 123 | fn get_left_child(i: usize) -> usize {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 15 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 17.13s
[INFO] running `Command { std: "docker" "inspect" "da244b7faae71239dc936a947250bbd08296c86cba30382ac747fa37b888f953", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "da244b7faae71239dc936a947250bbd08296c86cba30382ac747fa37b888f953", kill_on_drop: false }`
[INFO] [stdout] da244b7faae71239dc936a947250bbd08296c86cba30382ac747fa37b888f953
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-92/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-92/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8a1d1b6c06a1446d309a2f794a77380c35982e3dc0da3c203ad5ed0e531d3243
[INFO] running `Command { std: "docker" "start" "-a" "8a1d1b6c06a1446d309a2f794a77380c35982e3dc0da3c203ad5ed0e531d3243", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling exercises v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::collections::binary_heap`
[INFO] [stdout]  --> src/main.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::collections::binary_heap;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cmp::Ordering`
[INFO] [stdout]  --> src/heaps/heap.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cmp::Ordering;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `test_mat`
[INFO] [stdout]  --> src/mat.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn test_mat() {
[INFO] [stdout]   |        ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `det`
[INFO] [stdout]  --> src/mat.rs:7:4
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn det(mat: &[[f64; 3]; 3]) -> f64 {
[INFO] [stdout]   |    ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> src/heaps/comparator.rs:11:12
[INFO] [stdout]    |
[INFO] [stdout] 11 |     pub fn new() -> MinComparator {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `is_equal`
[INFO] [stdout]   --> src/heaps/comparator.rs:22:12
[INFO] [stdout]    |
[INFO] [stdout] 22 |     pub fn is_equal(self) -> bool {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `is_less`
[INFO] [stdout]   --> src/heaps/comparator.rs:34:12
[INFO] [stdout]    |
[INFO] [stdout] 34 |     pub fn is_less(self) -> bool {
[INFO] [stdout]    |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `unwrap`
[INFO] [stdout]   --> src/heaps/comparator.rs:40:12
[INFO] [stdout]    |
[INFO] [stdout] 40 |     pub fn unwrap(self) -> Ordering {
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `len`
[INFO] [stdout]   --> src/heaps/heap.rs:37:12
[INFO] [stdout]    |
[INFO] [stdout] 37 |     pub fn len(self) -> usize {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `peak`
[INFO] [stdout]   --> src/heaps/heap.rs:40:12
[INFO] [stdout]    |
[INFO] [stdout] 40 |     pub fn peak(self) -> Option<T> {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `remove_root`
[INFO] [stdout]   --> src/heaps/heap.rs:47:12
[INFO] [stdout]    |
[INFO] [stdout] 47 |     pub fn remove_root(&mut self) -> Option<T> {
[INFO] [stdout]    |            ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `sift_down`
[INFO] [stdout]   --> src/heaps/heap.rs:83:8
[INFO] [stdout]    |
[INFO] [stdout] 83 |     fn sift_down(&mut self, i: usize) {
[INFO] [stdout]    |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `get_right_child`
[INFO] [stdout]    --> src/heaps/heap.rs:120:4
[INFO] [stdout]     |
[INFO] [stdout] 120 | fn get_right_child(i: usize) -> usize {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `get_left_child`
[INFO] [stdout]    --> src/heaps/heap.rs:123:4
[INFO] [stdout]     |
[INFO] [stdout] 123 | fn get_left_child(i: usize) -> usize {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 14 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 57.13s
[INFO] running `Command { std: "docker" "inspect" "8a1d1b6c06a1446d309a2f794a77380c35982e3dc0da3c203ad5ed0e531d3243", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8a1d1b6c06a1446d309a2f794a77380c35982e3dc0da3c203ad5ed0e531d3243", kill_on_drop: false }`
[INFO] [stdout] 8a1d1b6c06a1446d309a2f794a77380c35982e3dc0da3c203ad5ed0e531d3243
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-92/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-92/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 5cbc55bbf20bccb05893c16dbd19b1eeb7c33474b3b2217d0474aa87eedc9808
[INFO] running `Command { std: "docker" "start" "-a" "5cbc55bbf20bccb05893c16dbd19b1eeb7c33474b3b2217d0474aa87eedc9808", kill_on_drop: false }`
[INFO] [stderr] warning: unused import: `std::collections::binary_heap`
[INFO] [stderr]  --> src/main.rs:7:5
[INFO] [stderr]   |
[INFO] [stderr] 7 | use std::collections::binary_heap;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::cmp::Ordering`
[INFO] [stderr]  --> src/heaps/heap.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::cmp::Ordering;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `test_mat`
[INFO] [stderr]  --> src/mat.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn test_mat() {
[INFO] [stderr]   |        ^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `det`
[INFO] [stderr]  --> src/mat.rs:7:4
[INFO] [stderr]   |
[INFO] [stderr] 7 | fn det(mat: &[[f64; 3]; 3]) -> f64 {
[INFO] [stderr]   |    ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `new`
[INFO] [stderr]   --> src/heaps/comparator.rs:11:12
[INFO] [stderr]    |
[INFO] [stderr] 11 |     pub fn new() -> MinComparator {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `is_equal`
[INFO] [stderr]   --> src/heaps/comparator.rs:22:12
[INFO] [stderr]    |
[INFO] [stderr] 22 |     pub fn is_equal(self) -> bool {
[INFO] [stderr]    |            ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `is_less`
[INFO] [stderr]   --> src/heaps/comparator.rs:34:12
[INFO] [stderr]    |
[INFO] [stderr] 34 |     pub fn is_less(self) -> bool {
[INFO] [stderr]    |            ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `unwrap`
[INFO] [stderr]   --> src/heaps/comparator.rs:40:12
[INFO] [stderr]    |
[INFO] [stderr] 40 |     pub fn unwrap(self) -> Ordering {
[INFO] [stderr]    |            ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `len`
[INFO] [stderr]   --> src/heaps/heap.rs:37:12
[INFO] [stdout] 
[INFO] [stderr]    |
[INFO] [stdout] running 4 tests
[INFO] [stderr] 37 |     pub fn len(self) -> usize {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `peak`
[INFO] [stderr]   --> src/heaps/heap.rs:40:12
[INFO] [stderr]    |
[INFO] [stderr] 40 |     pub fn peak(self) -> Option<T> {
[INFO] [stderr]    |            ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `remove_root`
[INFO] [stderr]   --> src/heaps/heap.rs:47:12
[INFO] [stderr]    |
[INFO] [stderr] 47 |     pub fn remove_root(&mut self) -> Option<T> {
[INFO] [stderr]    |            ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `sift_down`
[INFO] [stderr]   --> src/heaps/heap.rs:83:8
[INFO] [stderr]    |
[INFO] [stderr] 83 |     fn sift_down(&mut self, i: usize) {
[INFO] [stderr]    |        ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `get_right_child`
[INFO] [stderr]    --> src/heaps/heap.rs:120:4
[INFO] [stderr]     |
[INFO] [stderr] 120 | fn get_right_child(i: usize) -> usize {
[INFO] [stderr]     |    ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `get_left_child`
[INFO] [stderr]    --> src/heaps/heap.rs:123:4
[INFO] [stderr]     |
[INFO] [stderr] 123 | fn get_left_child(i: usize) -> usize {
[INFO] [stderr]     |    ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: `exercises` (bin "exercises" test) generated 14 warnings
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/exercises-af3962f3449cedbf)
[INFO] [stdout] test sorting::is_sorted::is_sorted_test ... ok
[INFO] [stdout] test sorting::quick_sort::partition_test ... ok
[INFO] [stdout] test sorting::quick_sort::quick_sort_test ... ok
[INFO] [stdout] test sorting::bubble_sort::bubble_sort_test ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 4 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 1.24s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "5cbc55bbf20bccb05893c16dbd19b1eeb7c33474b3b2217d0474aa87eedc9808", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5cbc55bbf20bccb05893c16dbd19b1eeb7c33474b3b2217d0474aa87eedc9808", kill_on_drop: false }`
[INFO] [stdout] 5cbc55bbf20bccb05893c16dbd19b1eeb7c33474b3b2217d0474aa87eedc9808