[INFO] cloning repository https://github.com/kamilWyszynski1/rust-first-steps
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/kamilWyszynski1/rust-first-steps" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FkamilWyszynski1%2Frust-first-steps", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FkamilWyszynski1%2Frust-first-steps'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 76a177555371d6735a49d5bd2305fbfacbe4bf4e
[INFO] testing kamilWyszynski1/rust-first-steps against 1.98.0-beta.8+cargoflags=--release for beta-release-1.99-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FkamilWyszynski1%2Frust-first-steps" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/kamilWyszynski1/rust-first-steps
[INFO] finished tweaking git repo https://github.com/kamilWyszynski1/rust-first-steps
[INFO] tweaked toml for git repo https://github.com/kamilWyszynski1/rust-first-steps written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/kamilWyszynski1/rust-first-steps on toolchain 1.98.0-beta.8
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.98.0-beta.8" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/kamilWyszynski1/rust-first-steps 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" "+1.98.0-beta.8" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded unicode-width v0.1.8
[INFO] [stderr]   Downloaded ferris-says v0.2.1
[INFO] [stderr]   Downloaded wasi v0.10.2+wasi-snapshot-preview1
[INFO] [stderr]   Downloaded textwrap v0.13.4
[INFO] [stderr]   Downloaded smawk v0.3.1
[INFO] [stderr]   Downloaded smallvec v0.4.5
[INFO] [stderr]   Downloaded libc v0.2.99
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,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" "-m" "1610612736" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:8683fc1fc2eb5c9ac98e0d076ab094b2ffac7f99da555d2b6a2e27f346de2ec7" "sleep" "infinity", kill_on_drop: false }`
[INFO] [stdout] 6f4e6b56c90bd8c2ff6c5a1dc7918f05a20bb8e8bcc07c438b37fca22842a84f
[INFO] running `Command { std: "docker" "start" "6f4e6b56c90bd8c2ff6c5a1dc7918f05a20bb8e8bcc07c438b37fca22842a84f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6f4e6b56c90bd8c2ff6c5a1dc7918f05a20bb8e8bcc07c438b37fca22842a84f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-w" "/opt/rustwide/workdir" "--user" "0:0" "6f4e6b56c90bd8c2ff6c5a1dc7918f05a20bb8e8bcc07c438b37fca22842a84f" "/opt/rustwide/cargo-home/bin/cargo" "+1.98.0-beta.8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6f4e6b56c90bd8c2ff6c5a1dc7918f05a20bb8e8bcc07c438b37fca22842a84f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-w" "/opt/rustwide/workdir" "--user" "0:0" "6f4e6b56c90bd8c2ff6c5a1dc7918f05a20bb8e8bcc07c438b37fca22842a84f" "/opt/rustwide/cargo-home/bin/cargo" "+1.98.0-beta.8" "build" "--frozen" "--message-format=json" "--release", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.99
[INFO] [stderr]    Compiling smawk v0.3.1
[INFO] [stderr]    Compiling ppv-lite86 v0.2.10
[INFO] [stderr]    Compiling unicode-width v0.1.8
[INFO] [stderr]    Compiling smallvec v0.4.5
[INFO] [stderr]    Compiling textwrap v0.13.4
[INFO] [stderr]    Compiling ferris-says v0.2.1
[INFO] [stderr]    Compiling getrandom v0.2.3
[INFO] [stderr]    Compiling rand_core v0.6.3
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling rand v0.8.4
[INFO] [stderr]    Compiling first-steps v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]    --> src/main.rs:304:9
[INFO] [stdout]     |
[INFO] [stdout] 304 |     let r1 = &s; // immutable ref
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]    --> src/main.rs:305:9
[INFO] [stdout]     |
[INFO] [stdout] 305 |     let r2 = &s; // another one, it's ok
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r3`
[INFO] [stdout]    --> src/main.rs:306:9
[INFO] [stdout]     |
[INFO] [stdout] 306 |     let r3 = &mut s; // problem
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_r3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]    --> src/main.rs:336:9
[INFO] [stdout]     |
[INFO] [stdout] 336 |     let hello = &s[0..5];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `world`
[INFO] [stdout]    --> src/main.rs:337:9
[INFO] [stdout]     |
[INFO] [stdout] 337 |     let world = &s[6..11];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_world`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]    --> src/main.rs:343:9
[INFO] [stdout]     |
[INFO] [stdout] 343 |     let slice = &s[0..len];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]    --> src/main.rs:344:9
[INFO] [stdout]     |
[INFO] [stdout] 344 |     let slice = &s[..];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]    --> src/main.rs:370:11
[INFO] [stdout]     |
[INFO] [stdout] 370 | fn change(s: &String) {
[INFO] [stdout]     |           ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:397:9
[INFO] [stdout]     |
[INFO] [stdout] 397 |     let mut user2 = User {
[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: `user2`
[INFO] [stdout]    --> src/main.rs:397:9
[INFO] [stdout]     |
[INFO] [stdout] 397 |     let mut user2 = User {
[INFO] [stdout]     |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_user2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user2`
[INFO] [stdout]    --> src/main.rs:416:9
[INFO] [stdout]     |
[INFO] [stdout] 416 |     let user2 = User {
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `no`
[INFO] [stdout]    --> src/main.rs:500:9
[INFO] [stdout]     |
[INFO] [stdout] 500 |     let no: Option<u8> = None;
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_no`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `references_and_borrowing` is never used
[INFO] [stdout]    --> src/main.rs:286:4
[INFO] [stdout]     |
[INFO] [stdout] 286 | fn references_and_borrowing() {
[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 `calculate_length` is never used
[INFO] [stdout]    --> src/main.rs:361:4
[INFO] [stdout]     |
[INFO] [stdout] 361 | fn calculate_length(s: String) -> usize {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `calculate_length_ref` is never used
[INFO] [stdout]    --> src/main.rs:366:4
[INFO] [stdout]     |
[INFO] [stdout] 366 | fn calculate_length_ref(str: &String) -> usize {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `change` is never used
[INFO] [stdout]    --> src/main.rs:370:4
[INFO] [stdout]     |
[INFO] [stdout] 370 | fn change(s: &String) {
[INFO] [stdout]     |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `change_mut` is never used
[INFO] [stdout]    --> src/main.rs:374:4
[INFO] [stdout]     |
[INFO] [stdout] 374 | fn change_mut(s: &mut String) {
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `structs` is never used
[INFO] [stdout]    --> src/main.rs:379:4
[INFO] [stdout]     |
[INFO] [stdout] 379 | fn structs() {
[INFO] [stdout]     |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `calc_rect_area` is never used
[INFO] [stdout]    --> src/main.rs:428:4
[INFO] [stdout]     |
[INFO] [stdout] 428 | fn calc_rect_area() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `area` and `update_x` are never used
[INFO] [stdout]    --> src/main.rs:433:12
[INFO] [stdout]     |
[INFO] [stdout] 432 |     impl Rectangle {
[INFO] [stdout]     |     -------------- methods in this implementation
[INFO] [stdout] 433 |         fn area(&self) -> i32 {
[INFO] [stdout]     |            ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 436 |         fn update_x(&mut self, x: i32) {
[INFO] [stdout]     |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `square` is never used
[INFO] [stdout]    --> src/main.rs:460:12
[INFO] [stdout]     |
[INFO] [stdout] 459 |     impl Rect {
[INFO] [stdout]     |     --------- associated function in this implementation
[INFO] [stdout] 460 |         fn square(size: u32) -> Rect {
[INFO] [stdout]     |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `enums` is never used
[INFO] [stdout]    --> src/main.rs:474:4
[INFO] [stdout]     |
[INFO] [stdout] 474 | fn enums() {
[INFO] [stdout]     |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `describe` is never used
[INFO] [stdout]    --> src/main.rs:481:12
[INFO] [stdout]     |
[INFO] [stdout] 480 |     impl IpAddrKind {
[INFO] [stdout]     |     --------------- method in this implementation
[INFO] [stdout] 481 |         fn describe(self) -> String {
[INFO] [stdout]     |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `common_collections` is never used
[INFO] [stdout]    --> src/main.rs:541:4
[INFO] [stdout]     |
[INFO] [stdout] 541 | fn common_collections() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `y` is never read
[INFO] [stdout]   --> src/generics.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 36 | struct Point<T> {
[INFO] [stdout]    |        ----- field in this struct
[INFO] [stdout] 37 |     x: T,
[INFO] [stdout] 38 |     y: T,
[INFO] [stdout]    |     ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Point` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `release` profile [optimized] target(s) in 3.47s
[INFO] running `Command { std: "docker" "inspect" "6f4e6b56c90bd8c2ff6c5a1dc7918f05a20bb8e8bcc07c438b37fca22842a84f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-w" "/opt/rustwide/workdir" "--user" "0:0" "6f4e6b56c90bd8c2ff6c5a1dc7918f05a20bb8e8bcc07c438b37fca22842a84f" "/opt/rustwide/cargo-home/bin/cargo" "+1.98.0-beta.8" "test" "--frozen" "--no-run" "--message-format=json" "--release", kill_on_drop: false }`
[INFO] [stderr]    Compiling first-steps v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]    --> src/main.rs:304:9
[INFO] [stdout]     |
[INFO] [stdout] 304 |     let r1 = &s; // immutable ref
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]    --> src/main.rs:305:9
[INFO] [stdout]     |
[INFO] [stdout] 305 |     let r2 = &s; // another one, it's ok
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r3`
[INFO] [stdout]    --> src/main.rs:306:9
[INFO] [stdout]     |
[INFO] [stdout] 306 |     let r3 = &mut s; // problem
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_r3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]    --> src/main.rs:336:9
[INFO] [stdout]     |
[INFO] [stdout] 336 |     let hello = &s[0..5];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `world`
[INFO] [stdout]    --> src/main.rs:337:9
[INFO] [stdout]     |
[INFO] [stdout] 337 |     let world = &s[6..11];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_world`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]    --> src/main.rs:343:9
[INFO] [stdout]     |
[INFO] [stdout] 343 |     let slice = &s[0..len];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]    --> src/main.rs:344:9
[INFO] [stdout]     |
[INFO] [stdout] 344 |     let slice = &s[..];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]    --> src/main.rs:370:11
[INFO] [stdout]     |
[INFO] [stdout] 370 | fn change(s: &String) {
[INFO] [stdout]     |           ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:397:9
[INFO] [stdout]     |
[INFO] [stdout] 397 |     let mut user2 = User {
[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: `user2`
[INFO] [stdout]    --> src/main.rs:397:9
[INFO] [stdout]     |
[INFO] [stdout] 397 |     let mut user2 = User {
[INFO] [stdout]     |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_user2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user2`
[INFO] [stdout]    --> src/main.rs:416:9
[INFO] [stdout]     |
[INFO] [stdout] 416 |     let user2 = User {
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `no`
[INFO] [stdout]    --> src/main.rs:500:9
[INFO] [stdout]     |
[INFO] [stdout] 500 |     let no: Option<u8> = None;
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_no`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `references_and_borrowing` is never used
[INFO] [stdout]    --> src/main.rs:286:4
[INFO] [stdout]     |
[INFO] [stdout] 286 | fn references_and_borrowing() {
[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 `calculate_length` is never used
[INFO] [stdout]    --> src/main.rs:361:4
[INFO] [stdout]     |
[INFO] [stdout] 361 | fn calculate_length(s: String) -> usize {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `calculate_length_ref` is never used
[INFO] [stdout]    --> src/main.rs:366:4
[INFO] [stdout]     |
[INFO] [stdout] 366 | fn calculate_length_ref(str: &String) -> usize {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `change` is never used
[INFO] [stdout]    --> src/main.rs:370:4
[INFO] [stdout]     |
[INFO] [stdout] 370 | fn change(s: &String) {
[INFO] [stdout]     |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `change_mut` is never used
[INFO] [stdout]    --> src/main.rs:374:4
[INFO] [stdout]     |
[INFO] [stdout] 374 | fn change_mut(s: &mut String) {
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `structs` is never used
[INFO] [stdout]    --> src/main.rs:379:4
[INFO] [stdout]     |
[INFO] [stdout] 379 | fn structs() {
[INFO] [stdout]     |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `calc_rect_area` is never used
[INFO] [stdout]    --> src/main.rs:428:4
[INFO] [stdout]     |
[INFO] [stdout] 428 | fn calc_rect_area() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `area` and `update_x` are never used
[INFO] [stdout]    --> src/main.rs:433:12
[INFO] [stdout]     |
[INFO] [stdout] 432 |     impl Rectangle {
[INFO] [stdout]     |     -------------- methods in this implementation
[INFO] [stdout] 433 |         fn area(&self) -> i32 {
[INFO] [stdout]     |            ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 436 |         fn update_x(&mut self, x: i32) {
[INFO] [stdout]     |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `square` is never used
[INFO] [stdout]    --> src/main.rs:460:12
[INFO] [stdout]     |
[INFO] [stdout] 459 |     impl Rect {
[INFO] [stdout]     |     --------- associated function in this implementation
[INFO] [stdout] 460 |         fn square(size: u32) -> Rect {
[INFO] [stdout]     |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `enums` is never used
[INFO] [stdout]    --> src/main.rs:474:4
[INFO] [stdout]     |
[INFO] [stdout] 474 | fn enums() {
[INFO] [stdout]     |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `describe` is never used
[INFO] [stdout]    --> src/main.rs:481:12
[INFO] [stdout]     |
[INFO] [stdout] 480 |     impl IpAddrKind {
[INFO] [stdout]     |     --------------- method in this implementation
[INFO] [stdout] 481 |         fn describe(self) -> String {
[INFO] [stdout]     |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `common_collections` is never used
[INFO] [stdout]    --> src/main.rs:541:4
[INFO] [stdout]     |
[INFO] [stdout] 541 | fn common_collections() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `y` is never read
[INFO] [stdout]   --> src/generics.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 36 | struct Point<T> {
[INFO] [stdout]    |        ----- field in this struct
[INFO] [stdout] 37 |     x: T,
[INFO] [stdout] 38 |     y: T,
[INFO] [stdout]    |     ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Point` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `release` profile [optimized] target(s) in 0.37s
[INFO] running `Command { std: "docker" "inspect" "6f4e6b56c90bd8c2ff6c5a1dc7918f05a20bb8e8bcc07c438b37fca22842a84f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-w" "/opt/rustwide/workdir" "--user" "0:0" "6f4e6b56c90bd8c2ff6c5a1dc7918f05a20bb8e8bcc07c438b37fca22842a84f" "/opt/rustwide/cargo-home/bin/cargo" "+1.98.0-beta.8" "test" "--frozen" "--release", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `r1`
[INFO] [stderr]    --> src/main.rs:304:9
[INFO] [stderr]     |
[INFO] [stderr] 304 |     let r1 = &s; // immutable ref
[INFO] [stderr]     |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `r2`
[INFO] [stderr]    --> src/main.rs:305:9
[INFO] [stderr]     |
[INFO] [stderr] 305 |     let r2 = &s; // another one, it's ok
[INFO] [stderr]     |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `r3`
[INFO] [stderr]    --> src/main.rs:306:9
[INFO] [stderr]     |
[INFO] [stderr] 306 |     let r3 = &mut s; // problem
[INFO] [stderr]     |         ^^ help: if this is intentional, prefix it with an underscore: `_r3`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `hello`
[INFO] [stderr]    --> src/main.rs:336:9
[INFO] [stderr]     |
[INFO] [stderr] 336 |     let hello = &s[0..5];
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `world`
[INFO] [stderr]    --> src/main.rs:337:9
[INFO] [stderr]     |
[INFO] [stderr] 337 |     let world = &s[6..11];
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_world`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `slice`
[INFO] [stderr]    --> src/main.rs:343:9
[INFO] [stderr]     |
[INFO] [stderr] 343 |     let slice = &s[0..len];
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `slice`
[INFO] [stderr]    --> src/main.rs:344:9
[INFO] [stderr]     |
[INFO] [stderr] 344 |     let slice = &s[..];
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s`
[INFO] [stderr]    --> src/main.rs:370:11
[INFO] [stderr]     |
[INFO] [stderr] 370 | fn change(s: &String) {
[INFO] [stderr]     |           ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:397:9
[INFO] [stderr]     |
[INFO] [stderr] 397 |     let mut user2 = User {
[INFO] [stderr]     |         ----^^^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `user2`
[INFO] [stderr]    --> src/main.rs:397:9
[INFO] [stderr]     |
[INFO] [stderr] 397 |     let mut user2 = User {
[INFO] [stderr]     |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_user2`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `user2`
[INFO] [stderr]    --> src/main.rs:416:9
[INFO] [stderr]     |
[INFO] [stderr] 416 |     let user2 = User {
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user2`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `no`
[INFO] [stderr]    --> src/main.rs:500:9
[INFO] [stderr]     |
[INFO] [stderr] 500 |     let no: Option<u8> = None;
[INFO] [stderr]     |         ^^ help: if this is intentional, prefix it with an underscore: `_no`
[INFO] [stderr] 
[INFO] [stderr] warning: function `references_and_borrowing` is never used
[INFO] [stderr]    --> src/main.rs:286:4
[INFO] [stderr]     |
[INFO] [stderr] 286 | fn references_and_borrowing() {
[INFO] [stderr]     |    ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function `calculate_length` is never used
[INFO] [stderr]    --> src/main.rs:361:4
[INFO] [stderr]     |
[INFO] [stderr] 361 | fn calculate_length(s: String) -> usize {
[INFO] [stderr]     |    ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `calculate_length_ref` is never used
[INFO] [stderr]    --> src/main.rs:366:4
[INFO] [stderr]     |
[INFO] [stderr] 366 | fn calculate_length_ref(str: &String) -> usize {
[INFO] [stderr]     |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `change` is never used
[INFO] [stderr]    --> src/main.rs:370:4
[INFO] [stderr]     |
[INFO] [stderr] 370 | fn change(s: &String) {
[INFO] [stderr]     |    ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `change_mut` is never used
[INFO] [stderr]    --> src/main.rs:374:4
[INFO] [stderr]     |
[INFO] [stderr] 374 | fn change_mut(s: &mut String) {
[INFO] [stderr]     |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `structs` is never used
[INFO] [stderr]    --> src/main.rs:379:4
[INFO] [stderr]     |
[INFO] [stderr] 379 | fn structs() {
[INFO] [stderr]     |    ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `calc_rect_area` is never used
[INFO] [stderr]    --> src/main.rs:428:4
[INFO] [stderr]     |
[INFO] [stderr] 428 | fn calc_rect_area() {
[INFO] [stderr]     |    ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: methods `area` and `update_x` are never used
[INFO] [stderr]    --> src/main.rs:433:12
[INFO] [stderr]     |
[INFO] [stderr] 432 |     impl Rectangle {
[INFO] [stderr]     |     -------------- methods in this implementation
[INFO] [stderr] 433 |         fn area(&self) -> i32 {
[INFO] [stderr]     |            ^^^^
[INFO] [stderr] ...
[INFO] [stderr] 436 |         fn update_x(&mut self, x: i32) {
[INFO] [stderr]     |            ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function `square` is never used
[INFO] [stderr]    --> src/main.rs:460:12
[INFO] [stderr]     |
[INFO] [stderr] 459 |     impl Rect {
[INFO] [stderr]     |     --------- associated function in this implementation
[INFO] [stderr] 460 |         fn square(size: u32) -> Rect {
[INFO] [stderr]     |            ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `enums` is never used
[INFO] [stderr]    --> src/main.rs:474:4
[INFO] [stderr]     |
[INFO] [stderr] 474 | fn enums() {
[INFO] [stderr]     |    ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method `describe` is never used
[INFO] [stderr]    --> src/main.rs:481:12
[INFO] [stderr]     |
[INFO] [stderr] 480 |     impl IpAddrKind {
[INFO] [stderr]     |     --------------- method in this implementation
[INFO] [stderr] 481 |         fn describe(self) -> String {
[INFO] [stderr]     |            ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `common_collections` is never used
[INFO] [stderr]    --> src/main.rs:541:4
[INFO] [stderr]     |
[INFO] [stderr] 541 | fn common_collections() {
[INFO] [stderr]     |    ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field `y` is never read
[INFO] [stderr]   --> src/generics.rs:38:5
[INFO] [stderr]    |
[INFO] [stderr] 36 | struct Point<T> {
[INFO] [stderr]    |        ----- field in this struct
[INFO] [stderr] 37 |     x: T,
[INFO] [stderr] 38 |     y: T,
[INFO] [stderr]    |     ^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `Point` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stderr] 
[INFO] [stderr] warning: `first-steps` (bin "first-steps" test) generated 25 warnings (run `cargo fix --bin "first-steps" -p first-steps --tests` to apply 12 suggestions)
[INFO] [stderr]     Finished `release` profile [optimized] target(s) in 0.03s
[INFO] [stderr]      Running unittests src/main.rs (/opt/rustwide/target/release/deps/first_steps-ee0f43472dd91a0b)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "6f4e6b56c90bd8c2ff6c5a1dc7918f05a20bb8e8bcc07c438b37fca22842a84f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6f4e6b56c90bd8c2ff6c5a1dc7918f05a20bb8e8bcc07c438b37fca22842a84f", kill_on_drop: false }`
[INFO] [stdout] 6f4e6b56c90bd8c2ff6c5a1dc7918f05a20bb8e8bcc07c438b37fca22842a84f
