[INFO] cloning repository https://github.com/Aypahyo/RustyGuessingGame
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Aypahyo/RustyGuessingGame" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAypahyo%2FRustyGuessingGame", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAypahyo%2FRustyGuessingGame'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 40f6fd6131cc0717149576f027eb002c649f4f1d
[INFO] checking Aypahyo/RustyGuessingGame against try#8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8 for pr-82565
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAypahyo%2FRustyGuessingGame" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Aypahyo/RustyGuessingGame on toolchain 8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Aypahyo/RustyGuessingGame
[INFO] finished tweaking git repo https://github.com/Aypahyo/RustyGuessingGame
[INFO] tweaked toml for git repo https://github.com/Aypahyo/RustyGuessingGame written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/Aypahyo/RustyGuessingGame already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded rspec v0.1.0
[INFO] [stderr]   Downloaded expectest v0.5.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c873ed122c676500008fa24cd3505e6d39481ffbc51a3699bff316701518e9f1
[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" "c873ed122c676500008fa24cd3505e6d39481ffbc51a3699bff316701518e9f1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c873ed122c676500008fa24cd3505e6d39481ffbc51a3699bff316701518e9f1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c873ed122c676500008fa24cd3505e6d39481ffbc51a3699bff316701518e9f1", kill_on_drop: false }`
[INFO] [stdout] c873ed122c676500008fa24cd3505e6d39481ffbc51a3699bff316701518e9f1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 7ea9fbaba49b892c36cf2ea885ce98df96132bb423f57134b294042329cb0b4e
[INFO] running `Command { std: "docker" "start" "-a" "7ea9fbaba49b892c36cf2ea885ce98df96132bb423f57134b294042329cb0b4e", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.80
[INFO] [stderr]    Compiling unicode-width v0.1.8
[INFO] [stderr]    Compiling syn v1.0.58
[INFO] [stderr]     Checking os_str_bytes v2.4.0
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]     Checking rand_core v0.3.1
[INFO] [stderr]     Checking rand_jitter v0.1.4
[INFO] [stderr]     Checking textwrap v0.12.1
[INFO] [stderr]     Checking rand_pcg v0.1.2
[INFO] [stderr]     Checking rand_xorshift v0.1.1
[INFO] [stderr]     Checking rand_isaac v0.1.1
[INFO] [stderr]     Checking rand_hc v0.1.0
[INFO] [stderr]     Checking rand_chacha v0.1.1
[INFO] [stderr]    Compiling getopts v0.2.21
[INFO] [stderr]    Compiling pulldown-cmark v0.0.3
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking rand_os v0.1.3
[INFO] [stderr]    Compiling rand v0.4.6
[INFO] [stderr]     Checking rand v0.6.5
[INFO] [stderr]     Checking num-traits v0.1.43
[INFO] [stderr]    Compiling tempdir v0.3.7
[INFO] [stderr]    Compiling skeptic v0.4.0
[INFO] [stderr]    Compiling expectest v0.5.1
[INFO] [stderr]     Checking rspec v0.1.0
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling clap_derive v3.0.0-beta.2
[INFO] [stderr]     Checking clap v3.0.0-beta.2
[INFO] [stderr]     Checking guessing_game v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]  --> src/chapters/chapter03_control_flow.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let x = 5;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |         let s = String::from("hello"); // s is valid from this point forward
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let y = x;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let s2 = s1.clone();
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let s1 = gives_ownership();                // gives_ownership moves its return
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let s3 = takes_and_gives_back(s2);  // s2 is moved into
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/chapters/chapter04_references_and_borrowing.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let r1 = &mut s;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/chapters/chapter04_references_and_borrowing.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let r2 = &mut s;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/chapters/chapter04_references_and_borrowing.rs:18:13
[INFO] [stdout]    |
[INFO] [stdout] 18 |         let r1 = &mut s;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/chapters/chapter04_references_and_borrowing.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let r2 = &mut s;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/chapters/chapter04_references_and_borrowing.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let r1 = &s; // no problem
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/chapters/chapter04_references_and_borrowing.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let r2 = &s; // no problem
[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/chapters/chapter04_references_and_borrowing.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let r3 = &mut s; // BIG PROBLEM
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `run`
[INFO] [stdout]  --> src/chapters/chapter00_arg_matches.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn run() {
[INFO] [stdout]   |        ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant is never used: `MAX_POINTS`
[INFO] [stdout]  --> src/chapters/chapter03_data_types.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub const MAX_POINTS: u32 = 100_000;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `run`
[INFO] [stdout]  --> src/chapters/chapter03_data_types.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn run() {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `fun`
[INFO] [stdout]  --> src/chapters/chapter02_guessing_game.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | fun() {
[INFO] [stdout]   | ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `run`
[INFO] [stdout]  --> src/chapters/chapter03_control_flow.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn run() {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `run`
[INFO] [stdout]  --> src/chapters/chapter03_functions.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn run() {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `another_function`
[INFO] [stdout]  --> src/chapters/chapter03_functions.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn another_function(x: i32) {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `five`
[INFO] [stdout]   --> src/chapters/chapter03_functions.rs:13:4
[INFO] [stdout]    |
[INFO] [stdout] 13 | fn five() -> i32 {
[INFO] [stdout]    |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `add_one`
[INFO] [stdout]   --> src/chapters/chapter03_functions.rs:17:4
[INFO] [stdout]    |
[INFO] [stdout] 17 | fn add_one(x: i32) -> i32 {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `do_twice`
[INFO] [stdout]   --> src/chapters/chapter03_functions.rs:21:4
[INFO] [stdout]    |
[INFO] [stdout] 21 | fn do_twice(f: fn(i32) -> i32, arg: i32) -> i32 {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `run`
[INFO] [stdout]  --> src/chapters/chapter04_ownership.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn run() {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `takes_ownership`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:44:4
[INFO] [stdout]    |
[INFO] [stdout] 44 | fn takes_ownership(some_string: String) {    // some_string comes into scope
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `makes_copy`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:49:4
[INFO] [stdout]    |
[INFO] [stdout] 49 | fn makes_copy(some_integer: i32) {           // some_integer comes into scope
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `run2`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:53:8
[INFO] [stdout]    |
[INFO] [stdout] 53 | pub fn run2() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `gives_ownership`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:63:4
[INFO] [stdout]    |
[INFO] [stdout] 63 | fn gives_ownership() -> String {             // gives_ownership will move its
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `takes_and_gives_back`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:74:4
[INFO] [stdout]    |
[INFO] [stdout] 74 | fn takes_and_gives_back(a_string: String) -> String { // a_string comes into
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 29 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]  --> src/chapters/chapter03_control_flow.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let x = 5;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |         let s = String::from("hello"); // s is valid from this point forward
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let y = x;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let s2 = s1.clone();
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let s1 = gives_ownership();                // gives_ownership moves its return
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let s3 = takes_and_gives_back(s2);  // s2 is moved into
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/chapters/chapter04_references_and_borrowing.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let r1 = &mut s;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/chapters/chapter04_references_and_borrowing.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let r2 = &mut s;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/chapters/chapter04_references_and_borrowing.rs:18:13
[INFO] [stdout]    |
[INFO] [stdout] 18 |         let r1 = &mut s;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/chapters/chapter04_references_and_borrowing.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let r2 = &mut s;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/chapters/chapter04_references_and_borrowing.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let r1 = &s; // no problem
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/chapters/chapter04_references_and_borrowing.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let r2 = &s; // no problem
[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/chapters/chapter04_references_and_borrowing.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let r3 = &mut s; // BIG PROBLEM
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `run`
[INFO] [stdout]  --> src/chapters/chapter00_arg_matches.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn run() {
[INFO] [stdout]   |        ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant is never used: `MAX_POINTS`
[INFO] [stdout]  --> src/chapters/chapter03_data_types.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub const MAX_POINTS: u32 = 100_000;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `run`
[INFO] [stdout]  --> src/chapters/chapter03_data_types.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn run() {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `fun`
[INFO] [stdout]  --> src/chapters/chapter02_guessing_game.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | fun() {
[INFO] [stdout]   | ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `run`
[INFO] [stdout]  --> src/chapters/chapter03_control_flow.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn run() {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `run`
[INFO] [stdout]  --> src/chapters/chapter03_functions.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn run() {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `another_function`
[INFO] [stdout]  --> src/chapters/chapter03_functions.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn another_function(x: i32) {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `five`
[INFO] [stdout]   --> src/chapters/chapter03_functions.rs:13:4
[INFO] [stdout]    |
[INFO] [stdout] 13 | fn five() -> i32 {
[INFO] [stdout]    |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `add_one`
[INFO] [stdout]   --> src/chapters/chapter03_functions.rs:17:4
[INFO] [stdout]    |
[INFO] [stdout] 17 | fn add_one(x: i32) -> i32 {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `do_twice`
[INFO] [stdout]   --> src/chapters/chapter03_functions.rs:21:4
[INFO] [stdout]    |
[INFO] [stdout] 21 | fn do_twice(f: fn(i32) -> i32, arg: i32) -> i32 {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `run`
[INFO] [stdout]  --> src/chapters/chapter04_ownership.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn run() {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `takes_ownership`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:44:4
[INFO] [stdout]    |
[INFO] [stdout] 44 | fn takes_ownership(some_string: String) {    // some_string comes into scope
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `makes_copy`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:49:4
[INFO] [stdout]    |
[INFO] [stdout] 49 | fn makes_copy(some_integer: i32) {           // some_integer comes into scope
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `run2`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:53:8
[INFO] [stdout]    |
[INFO] [stdout] 53 | pub fn run2() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `gives_ownership`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:63:4
[INFO] [stdout]    |
[INFO] [stdout] 63 | fn gives_ownership() -> String {             // gives_ownership will move its
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `takes_and_gives_back`
[INFO] [stdout]   --> src/chapters/chapter04_ownership.rs:74:4
[INFO] [stdout]    |
[INFO] [stdout] 74 | fn takes_and_gives_back(a_string: String) -> String { // a_string comes into
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 29 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 22.45s
[INFO] running `Command { std: "docker" "inspect" "7ea9fbaba49b892c36cf2ea885ce98df96132bb423f57134b294042329cb0b4e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7ea9fbaba49b892c36cf2ea885ce98df96132bb423f57134b294042329cb0b4e", kill_on_drop: false }`
[INFO] [stdout] 7ea9fbaba49b892c36cf2ea885ce98df96132bb423f57134b294042329cb0b4e