[INFO] cloning repository https://github.com/levchik/cses
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/levchik/cses" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flevchik%2Fcses", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flevchik%2Fcses'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] aaf8b936f700867a500237d0101408bfa402b292
[INFO] checking levchik/cses against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flevchik%2Fcses" "/workspace/builds/worker-1-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/levchik/cses
[INFO] finished tweaking git repo https://github.com/levchik/cses
[INFO] tweaked toml for git repo https://github.com/levchik/cses written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/levchik/cses on toolchain 4f260f0f20b3133d20cfb50353c0221943af5796
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/levchik/cses 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" "+4f260f0f20b3133d20cfb50353c0221943af5796" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e7894796f891d2963ea650d5dd0a229512a8ffe4b5fc8dffb3ca0ecb2cbf9e8b
[INFO] running `Command { std: "docker" "start" "-a" "e7894796f891d2963ea650d5dd0a229512a8ffe4b5fc8dffb3ca0ecb2cbf9e8b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e7894796f891d2963ea650d5dd0a229512a8ffe4b5fc8dffb3ca0ecb2cbf9e8b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e7894796f891d2963ea650d5dd0a229512a8ffe4b5fc8dffb3ca0ecb2cbf9e8b", kill_on_drop: false }`
[INFO] [stdout] e7894796f891d2963ea650d5dd0a229512a8ffe4b5fc8dffb3ca0ecb2cbf9e8b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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 -Dunmustuse_in_always_ok" "-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" "+4f260f0f20b3133d20cfb50353c0221943af5796" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6bba2baaf9162d30af1e469d4e4b32ff7843f77415255d14b7aeacb69f7ce763
[INFO] running `Command { std: "docker" "start" "-a" "6bba2baaf9162d30af1e469d4e4b32ff7843f77415255d14b7aeacb69f7ce763", kill_on_drop: false }`
[INFO] [stderr]     Checking cses-book v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/problems/apple_division.rs:20:25
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let mut ans: i128 = (1 << 63);
[INFO] [stdout]    |                         ^       ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 20 -     let mut ans: i128 = (1 << 63);
[INFO] [stdout] 20 +     let mut ans: i128 = 1 << 63;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/problems/apple_division.rs:28:21
[INFO] [stdout]    |
[INFO] [stdout] 28 |             let d = (1 << j);
[INFO] [stdout]    |                     ^      ^
[INFO] [stdout]    |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 28 -             let d = (1 << j);
[INFO] [stdout] 28 +             let d = 1 << j;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/problems/apple_division.rs:29:24
[INFO] [stdout]    |
[INFO] [stdout] 29 |             let dand = (i & d);
[INFO] [stdout]    |                        ^     ^
[INFO] [stdout]    |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 29 -             let dand = (i & d);
[INFO] [stdout] 29 +             let dand = i & d;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `stdout`
[INFO] [stdout]  --> src/problems/gray_code.rs:3:22
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::io::{stdin, stdout};
[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 import: `stdout`
[INFO] [stdout]  --> src/problems/palindrome_reoder.rs:3:22
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::io::{stdin, stdout};
[INFO] [stdout]   |                      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around index expression
[INFO] [stdout]   --> src/problems/palindrome_reoder.rs:14:20
[INFO] [stdout]    |
[INFO] [stdout] 14 |         occurences[(c as usize - 65)] += 1;
[INFO] [stdout]    |                    ^               ^
[INFO] [stdout]    |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 14 -         occurences[(c as usize - 65)] += 1;
[INFO] [stdout] 14 +         occurences[c as usize - 65] += 1;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/problems/palindrome_reoder.rs:20:22
[INFO] [stdout]    |
[INFO] [stdout] 20 |         odd_check += (occurences[i] % 2);
[INFO] [stdout]    |                      ^                 ^
[INFO] [stdout]    |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 20 -         odd_check += (occurences[i] % 2);
[INFO] [stdout] 20 +         odd_check += occurences[i] % 2;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/problems/palindrome_reoder.rs:25:12
[INFO] [stdout]    |
[INFO] [stdout] 25 |         if (occurences[i] % 2 == 0) {
[INFO] [stdout]    |            ^                      ^
[INFO] [stdout]    |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 25 -         if (occurences[i] % 2 == 0) {
[INFO] [stdout] 25 +         if occurences[i] % 2 == 0 {
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/problems/palindrome_reoder.rs:35:12
[INFO] [stdout]    |
[INFO] [stdout] 35 |         if (occurences[i] % 2 == 0) {
[INFO] [stdout]    |            ^                      ^
[INFO] [stdout]    |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 35 -         if (occurences[i] % 2 == 0) {
[INFO] [stdout] 35 +         if occurences[i] % 2 == 0 {
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `stdout`
[INFO] [stdout]  --> src/problems/repetitions.rs:3:22
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::io::{stdin, stdout};
[INFO] [stdout]   |                      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `stdout`
[INFO] [stdout]  --> src/problems/tower_of_hanoi.rs:3:22
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::io::{stdin, stdout};
[INFO] [stdout]   |                      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/problems/apple_division.rs:20:25
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let mut ans: i128 = (1 << 63);
[INFO] [stdout]    |                         ^       ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 20 -     let mut ans: i128 = (1 << 63);
[INFO] [stdout] 20 +     let mut ans: i128 = 1 << 63;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/problems/apple_division.rs:28:21
[INFO] [stdout]    |
[INFO] [stdout] 28 |             let d = (1 << j);
[INFO] [stdout]    |                     ^      ^
[INFO] [stdout]    |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 28 -             let d = (1 << j);
[INFO] [stdout] 28 +             let d = 1 << j;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/problems/apple_division.rs:29:24
[INFO] [stdout]    |
[INFO] [stdout] 29 |             let dand = (i & d);
[INFO] [stdout]    |                        ^     ^
[INFO] [stdout]    |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 29 -             let dand = (i & d);
[INFO] [stdout] 29 +             let dand = i & d;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `stdout`
[INFO] [stdout]  --> src/problems/gray_code.rs:3:22
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::io::{stdin, stdout};
[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 import: `stdout`
[INFO] [stdout]  --> src/problems/palindrome_reoder.rs:3:22
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::io::{stdin, stdout};
[INFO] [stdout]   |                      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around index expression
[INFO] [stdout]   --> src/problems/palindrome_reoder.rs:14:20
[INFO] [stdout]    |
[INFO] [stdout] 14 |         occurences[(c as usize - 65)] += 1;
[INFO] [stdout]    |                    ^               ^
[INFO] [stdout]    |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 14 -         occurences[(c as usize - 65)] += 1;
[INFO] [stdout] 14 +         occurences[c as usize - 65] += 1;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/problems/palindrome_reoder.rs:20:22
[INFO] [stdout]    |
[INFO] [stdout] 20 |         odd_check += (occurences[i] % 2);
[INFO] [stdout]    |                      ^                 ^
[INFO] [stdout]    |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 20 -         odd_check += (occurences[i] % 2);
[INFO] [stdout] 20 +         odd_check += occurences[i] % 2;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/problems/palindrome_reoder.rs:25:12
[INFO] [stdout]    |
[INFO] [stdout] 25 |         if (occurences[i] % 2 == 0) {
[INFO] [stdout]    |            ^                      ^
[INFO] [stdout]    |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 25 -         if (occurences[i] % 2 == 0) {
[INFO] [stdout] 25 +         if occurences[i] % 2 == 0 {
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/problems/palindrome_reoder.rs:35:12
[INFO] [stdout]    |
[INFO] [stdout] 35 |         if (occurences[i] % 2 == 0) {
[INFO] [stdout]    |            ^                      ^
[INFO] [stdout]    |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 35 -         if (occurences[i] % 2 == 0) {
[INFO] [stdout] 35 +         if occurences[i] % 2 == 0 {
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `stdout`
[INFO] [stdout]  --> src/problems/repetitions.rs:3:22
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::io::{stdin, stdout};
[INFO] [stdout]   |                      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `stdout`
[INFO] [stdout]  --> src/problems/tower_of_hanoi.rs:3:22
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::io::{stdin, stdout};
[INFO] [stdout]   |                      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/problems/bit_strings.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     for i in 1..n {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/problems/digit_queries.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     for i in 0..n {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/problems/bit_strings.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     for i in 1..n {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/problems/increasing_array.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let mut nums: Vec<i128> = input.trim_end()
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/problems/number_spiral.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     for i in 1..n+1 {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/problems/digit_queries.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     for i in 0..n {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/problems/increasing_array.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let mut nums: Vec<i128> = input.trim_end()
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/apple_division.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/bit_strings.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/coin_piles.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `swap` is never used
[INFO] [stdout]  --> src/problems/creating_strings.rs:5:4
[INFO] [stdout]   |
[INFO] [stdout] 5 | fn swap(a: &Vec<char>, i: usize, j: usize) -> Vec<char> {
[INFO] [stdout]   |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `perm` is never used
[INFO] [stdout]   --> src/problems/creating_strings.rs:13:4
[INFO] [stdout]    |
[INFO] [stdout] 13 | fn perm(new: &mut Vec<String>, a: &Vec<char>, start: usize) {
[INFO] [stdout]    |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]   --> src/problems/creating_strings.rs:26:8
[INFO] [stdout]    |
[INFO] [stdout] 26 | pub fn main() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/increasing_array.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/gray_code.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/missing_number.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/number_spiral.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/palindrome_reoder.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/permutations.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/repetitions.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/tower_of_hanoi.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/trailing_zeros.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/two_knights.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/two_sets.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Scanner` is never constructed
[INFO] [stdout]  --> src/problems/weird_algorithm.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | struct Scanner {
[INFO] [stdout]   |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `next` is never used
[INFO] [stdout]  --> src/problems/weird_algorithm.rs:9:8
[INFO] [stdout]   |
[INFO] [stdout] 8 | impl Scanner {
[INFO] [stdout]   | ------------ method in this implementation
[INFO] [stdout] 9 |     fn next<T: std::str::FromStr>(&mut self) -> T {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]   --> src/problems/weird_algorithm.rs:22:8
[INFO] [stdout]    |
[INFO] [stdout] 22 | pub fn main() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/problems/number_spiral.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     for i in 1..n+1 {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/problems/creating_strings.rs:29:21
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let s: String = n_input.trim_end().parse().unwrap();
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]  --> src/problems/palindrome_reoder.rs:8:21
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let s: String = n_input.trim_end().parse().unwrap();
[INFO] [stdout]   |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/apple_division.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/bit_strings.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/coin_piles.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `swap` is never used
[INFO] [stdout]  --> src/problems/creating_strings.rs:5:4
[INFO] [stdout]   |
[INFO] [stdout] 5 | fn swap(a: &Vec<char>, i: usize, j: usize) -> Vec<char> {
[INFO] [stdout]   |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `perm` is never used
[INFO] [stdout]   --> src/problems/creating_strings.rs:13:4
[INFO] [stdout]    |
[INFO] [stdout] 13 | fn perm(new: &mut Vec<String>, a: &Vec<char>, start: usize) {
[INFO] [stdout]    |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]   --> src/problems/creating_strings.rs:26:8
[INFO] [stdout]    |
[INFO] [stdout] 26 | pub fn main() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/increasing_array.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/gray_code.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/missing_number.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/number_spiral.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/palindrome_reoder.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/permutations.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/repetitions.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/tower_of_hanoi.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/trailing_zeros.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/two_knights.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/problems/two_sets.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Scanner` is never constructed
[INFO] [stdout]  --> src/problems/weird_algorithm.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | struct Scanner {
[INFO] [stdout]   |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `next` is never used
[INFO] [stdout]  --> src/problems/weird_algorithm.rs:9:8
[INFO] [stdout]   |
[INFO] [stdout] 8 | impl Scanner {
[INFO] [stdout]   | ------------ method in this implementation
[INFO] [stdout] 9 |     fn next<T: std::str::FromStr>(&mut self) -> T {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]   --> src/problems/weird_algorithm.rs:22:8
[INFO] [stdout]    |
[INFO] [stdout] 22 | pub fn main() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/problems/creating_strings.rs:29:21
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let s: String = n_input.trim_end().parse().unwrap();
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]  --> src/problems/palindrome_reoder.rs:8:21
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let s: String = n_input.trim_end().parse().unwrap();
[INFO] [stdout]   |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `cses-book` (bin "cses-book") due to 2 previous errors; 35 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `cses-book` (bin "cses-book" test) due to 2 previous errors; 35 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "6bba2baaf9162d30af1e469d4e4b32ff7843f77415255d14b7aeacb69f7ce763", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6bba2baaf9162d30af1e469d4e4b32ff7843f77415255d14b7aeacb69f7ce763", kill_on_drop: false }`
[INFO] [stdout] 6bba2baaf9162d30af1e469d4e4b32ff7843f77415255d14b7aeacb69f7ce763