[INFO] cloning repository https://github.com/clD11/rust-katas
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/clD11/rust-katas" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FclD11%2Frust-katas", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FclD11%2Frust-katas'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7c397278231c9d92a9c5ac928fff855e347d983d
[INFO] checking clD11/rust-katas against master#a609fb45efad59dfd459c76e50899be9f0583b5a for pr-80579
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FclD11%2Frust-katas" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/clD11/rust-katas on toolchain a609fb45efad59dfd459c76e50899be9f0583b5a
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/clD11/rust-katas
[INFO] finished tweaking git repo https://github.com/clD11/rust-katas
[INFO] tweaked toml for git repo https://github.com/clD11/rust-katas written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/clD11/rust-katas already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6d40fb2b60d5b4c2d376399fe5be75b081a5e609094dee8faecf0753332dc716
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "6d40fb2b60d5b4c2d376399fe5be75b081a5e609094dee8faecf0753332dc716", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6d40fb2b60d5b4c2d376399fe5be75b081a5e609094dee8faecf0753332dc716", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6d40fb2b60d5b4c2d376399fe5be75b081a5e609094dee8faecf0753332dc716", kill_on_drop: false }`
[INFO] [stdout] 6d40fb2b60d5b4c2d376399fe5be75b081a5e609094dee8faecf0753332dc716
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e66376819f0a6e18c4443e8a54880c182b1aedd1410ae613b2acf8a6babee5dd
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "e66376819f0a6e18c4443e8a54880c182b1aedd1410ae613b2acf8a6babee5dd", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.68
[INFO] [stderr]     Checking getrandom v0.1.14
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking rust-katas v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `Stdin`
[INFO] [stdout]  --> src/hackerrank/problem_solving/missing_numbers.rs:2:24
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::{BufRead, Stdin};
[INFO] [stdout]   |                        ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> src/hackerrank/problem_solving/sherlock_and_array.rs:35:45
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let mut left_count: u32 = arr[pos_left];;
[INFO] [stdout]    |                                             ^ help: remove this semicolon
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(redundant_semicolons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Stdin`
[INFO] [stdout]  --> src/hackerrank/utils.rs:2:24
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::{BufRead, Stdin};
[INFO] [stdout]   |                        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io`
[INFO] [stdout]  --> src/main.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 | use std::io;
[INFO] [stdout]   |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `BufRead`
[INFO] [stdout]  --> src/main.rs:9:15
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::io::{BufRead};
[INFO] [stdout]   |               ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Stdin`
[INFO] [stdout]  --> src/hackerrank/problem_solving/missing_numbers.rs:2:24
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::{BufRead, Stdin};
[INFO] [stdout]   |                        ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> src/hackerrank/problem_solving/sherlock_and_array.rs:35:45
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let mut left_count: u32 = arr[pos_left];;
[INFO] [stdout]    |                                             ^ help: remove this semicolon
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(redundant_semicolons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Stdin`
[INFO] [stdout]  --> src/hackerrank/utils.rs:2:24
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::{BufRead, Stdin};
[INFO] [stdout]   |                        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::string::String`
[INFO] [stdout]  --> src/rust_book/slice.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::string::String;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io`
[INFO] [stdout]  --> src/main.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 | use std::io;
[INFO] [stdout]   |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `BufRead`
[INFO] [stdout]  --> src/main.rs:9:15
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::io::{BufRead};
[INFO] [stdout]   |               ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `BufRead`
[INFO] [stdout]  --> src/hackerrank/problem_solving/ice_cream_parlor.rs:3:15
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::io::{BufRead};
[INFO] [stdout]   |               ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `BufRead`
[INFO] [stdout]  --> src/hackerrank/problem_solving/missing_numbers.rs:2:15
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::{BufRead, Stdin};
[INFO] [stdout]   |               ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `BufRead`
[INFO] [stdout]  --> src/hackerrank/utils.rs:2:15
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::{BufRead, Stdin};
[INFO] [stdout]   |               ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `pair` is never read
[INFO] [stdout]  --> src/hackerrank/problem_solving/pairs.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let mut pair: u32 = 0;
[INFO] [stdout]   |         ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/hackerrank/problem_solving/sherlock_and_array.rs:69:9
[INFO] [stdout]    |
[INFO] [stdout] 69 |     for i in 0..cases {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/hackerrank/problem_solving/pairs.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let mut boxed: Box<[u32; 2]> = Box::new(arr);
[INFO] [stdout]    |         ----^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `BufRead`
[INFO] [stdout]  --> src/hackerrank/problem_solving/ice_cream_parlor.rs:3:15
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::io::{BufRead};
[INFO] [stdout]   |               ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `BufRead`
[INFO] [stdout]  --> src/hackerrank/problem_solving/missing_numbers.rs:2:15
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::{BufRead, Stdin};
[INFO] [stdout]   |               ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `BufRead`
[INFO] [stdout]  --> src/hackerrank/utils.rs:2:15
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::{BufRead, Stdin};
[INFO] [stdout]   |               ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable if-let pattern
[INFO] [stdout]   --> src/rust_book/defining_enums.rs:9:5
[INFO] [stdout]    |
[INFO] [stdout] 9  | /     if let IpAddrKind::V4(actual) = V4 {
[INFO] [stdout] 10 | |         assert_eq!(actual, expected);
[INFO] [stdout] 11 | |     }
[INFO] [stdout]    | |_____^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `pair` is never read
[INFO] [stdout]  --> src/hackerrank/problem_solving/pairs.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let mut pair: u32 = 0;
[INFO] [stdout]   |         ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `cat_and_mouse`
[INFO] [stdout]  --> src/hackerrank/problem_solving/cat_mouse.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn cat_and_mouse(x: i32, y: i32, z: i32) -> &'static str {
[INFO] [stdout]   |        ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `divisible_sum_pairs`
[INFO] [stdout]  --> src/hackerrank/problem_solving/divisible_sum_pairs.rs:1:9
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn  divisible_sum_pairs(n: usize, k: u32, ar: &[u32]) -> u32 {
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `sum`
[INFO] [stdout]  --> src/hackerrank/problem_solving/distinct_pairs.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn sum(nums: &[u32], target: u32) -> u32 {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/hackerrank/problem_solving/sherlock_and_array.rs:69:9
[INFO] [stdout]    |
[INFO] [stdout] 69 |     for i in 0..cases {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `to_roman_numeral`
[INFO] [stdout]   --> src/hackerrank/problem_solving/number_converter.rs:26:8
[INFO] [stdout]    |
[INFO] [stdout] 26 | pub fn to_roman_numeral(number: u32) -> String {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `find_digits`
[INFO] [stdout]  --> src/hackerrank/problem_solving/find_digits.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn find_digits(n: u32) -> u32 {
[INFO] [stdout]   |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `fair_rations`
[INFO] [stdout]  --> src/hackerrank/problem_solving/fair_rations.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn fair_rations(arr: &[u32]) -> &'static str {
[INFO] [stdout]   |        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `find_pairs_to_target`
[INFO] [stdout]  --> src/hackerrank/problem_solving/pairs.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn find_pairs_to_target(input: Vec<u32>, target: u32) -> u32 {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `pairs_boxed`
[INFO] [stdout]   --> src/hackerrank/problem_solving/pairs.rs:21:4
[INFO] [stdout]    |
[INFO] [stdout] 21 | fn pairs_boxed() -> Box<[u32; 2]> {
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `pairs_vec`
[INFO] [stdout]   --> src/hackerrank/problem_solving/pairs.rs:27:4
[INFO] [stdout]    |
[INFO] [stdout] 27 | fn pairs_vec() -> Vec<[u32; 2]> {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `is_divisible_by`
[INFO] [stdout]  --> src/hackerrank/problem_solving/fizz_buzz.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn is_divisible_by(lhs: u32, rhs: u32) -> bool {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `fizzbuzz`
[INFO] [stdout]  --> src/hackerrank/problem_solving/fizz_buzz.rs:8:4
[INFO] [stdout]   |
[INFO] [stdout] 8 | fn fizzbuzz(n : u32) {
[INFO] [stdout]   |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `fizzbuzz_to`
[INFO] [stdout]   --> src/hackerrank/problem_solving/fizz_buzz.rs:20:4
[INFO] [stdout]    |
[INFO] [stdout] 20 | fn fizzbuzz_to(n: u32) {
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `what_flavours`
[INFO] [stdout]  --> src/hackerrank/problem_solving/ice_cream_parlor.rs:6:4
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn what_flavours(flavours: &Vec<u32>, money: &u32) -> [u32; 2] {
[INFO] [stdout]   |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read`
[INFO] [stdout]   --> src/hackerrank/problem_solving/ice_cream_parlor.rs:42:8
[INFO] [stdout]    |
[INFO] [stdout] 42 | pub fn read() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `missing_numbers`
[INFO] [stdout]  --> src/hackerrank/problem_solving/missing_numbers.rs:7:4
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn missing_numbers(arr: &Vec<u32>, brr: &Vec<u32>) -> Vec<u32> {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_num`
[INFO] [stdout]   --> src/hackerrank/problem_solving/missing_numbers.rs:31:4
[INFO] [stdout]    |
[INFO] [stdout] 31 | fn read_num() -> u32 {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_vec`
[INFO] [stdout]   --> src/hackerrank/problem_solving/missing_numbers.rs:37:4
[INFO] [stdout]    |
[INFO] [stdout] 37 | fn read_vec() -> Vec<u32> {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `main`
[INFO] [stdout]   --> src/hackerrank/problem_solving/missing_numbers.rs:45:8
[INFO] [stdout]    |
[INFO] [stdout] 45 | pub fn main() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `balanced_sums_count`
[INFO] [stdout]  --> src/hackerrank/problem_solving/sherlock_and_array.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn balanced_sums_count(arr: &Vec<u32>) -> &str {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `IpAddrKind`
[INFO] [stdout]  --> src/rust_book/defining_enums.rs:1:6
[INFO] [stdout]   |
[INFO] [stdout] 1 | enum IpAddrKind {
[INFO] [stdout]   |      ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `guess`
[INFO] [stdout]  --> src/rust_book/guessing_game.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn guess() {
[INFO] [stdout]   |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `square`
[INFO] [stdout]   --> src/rust_book/rectangle.rs:13:8
[INFO] [stdout]    |
[INFO] [stdout] 13 |     fn square(d: i32) -> Rectangle {
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `area`
[INFO] [stdout]   --> src/rust_book/rectangle.rs:20:8
[INFO] [stdout]    |
[INFO] [stdout] 20 |     fn area(&self) -> i32 {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `can_hold`
[INFO] [stdout]   --> src/rust_book/rectangle.rs:24:8
[INFO] [stdout]    |
[INFO] [stdout] 24 |     fn can_hold(&self, rectangle: &Rectangle) -> bool { self.area() >= rectangle.area() }
[INFO] [stdout]    |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `find_first_word`
[INFO] [stdout]  --> src/rust_book/slice.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 8 | pub fn find_first_word(s: &str) -> &str {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 37 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/hackerrank/problem_solving/pairs.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let mut boxed: Box<[u32; 2]> = Box::new(arr);
[INFO] [stdout]    |         ----^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/hackerrank/problem_solving/missing_numbers.rs:63:13
[INFO] [stdout]    |
[INFO] [stdout] 63 |         let mut expected: Vec<u32> = vec![204, 205, 206];
[INFO] [stdout]    |             ----^^^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/hackerrank/problem_solving/missing_numbers.rs:74:13
[INFO] [stdout]    |
[INFO] [stdout] 74 |         let mut expected: Vec<u32> = vec![4, 6];
[INFO] [stdout]    |             ----^^^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read`
[INFO] [stdout]   --> src/hackerrank/problem_solving/ice_cream_parlor.rs:42:8
[INFO] [stdout]    |
[INFO] [stdout] 42 | pub fn read() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_num`
[INFO] [stdout]   --> src/hackerrank/problem_solving/missing_numbers.rs:31:4
[INFO] [stdout]    |
[INFO] [stdout] 31 | fn read_num() -> u32 {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_vec`
[INFO] [stdout]   --> src/hackerrank/problem_solving/missing_numbers.rs:37:4
[INFO] [stdout]    |
[INFO] [stdout] 37 | fn read_vec() -> Vec<u32> {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `main`
[INFO] [stdout]   --> src/hackerrank/problem_solving/missing_numbers.rs:45:8
[INFO] [stdout]    |
[INFO] [stdout] 45 | pub fn main() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `guess`
[INFO] [stdout]  --> src/rust_book/guessing_game.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn guess() {
[INFO] [stdout]   |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `shouldReturnNo` should have a snake case name
[INFO] [stdout]   --> src/hackerrank/problem_solving/fair_rations.rs:14:4
[INFO] [stdout]    |
[INFO] [stdout] 14 | fn shouldReturnNo() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^ help: convert the identifier to snake case: `should_return_no`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `shouldReturnNumber` should have a snake case name
[INFO] [stdout]   --> src/hackerrank/problem_solving/fair_rations.rs:21:4
[INFO] [stdout]    |
[INFO] [stdout] 21 | fn shouldReturnNumber() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^ help: convert the identifier to snake case: `should_return_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_V4` should have a snake case name
[INFO] [stdout]  --> src/rust_book/defining_enums.rs:6:4
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn test_V4() {
[INFO] [stdout]   |    ^^^^^^^ help: convert the identifier to snake case (notice the capitalization): `test_v4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `V4` should have a snake case name
[INFO] [stdout]  --> src/rust_book/defining_enums.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let V4 = IpAddrKind::V4(String::from("127.0.0.1"));
[INFO] [stdout]   |         ^^ help: convert the identifier to snake case (notice the capitalization): `v4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 23 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.03s
[INFO] running `Command { std: "docker" "inspect" "e66376819f0a6e18c4443e8a54880c182b1aedd1410ae613b2acf8a6babee5dd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e66376819f0a6e18c4443e8a54880c182b1aedd1410ae613b2acf8a6babee5dd", kill_on_drop: false }`
[INFO] [stdout] e66376819f0a6e18c4443e8a54880c182b1aedd1410ae613b2acf8a6babee5dd