[INFO] cloning repository https://github.com/dansaldt/rustbook
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/dansaldt/rustbook" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdansaldt%2Frustbook", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdansaldt%2Frustbook'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 89031e10c5cc1e5ae7b9a9075bd03d7e0106fc23
[INFO] checking dansaldt/rustbook against master#33fdb797f59421c7bbecaa4588ed5d7a31a9494a for pr-87190-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdansaldt%2Frustbook" "/workspace/builds/worker-14/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-14/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/dansaldt/rustbook on toolchain 33fdb797f59421c7bbecaa4588ed5d7a31a9494a
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+33fdb797f59421c7bbecaa4588ed5d7a31a9494a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/dansaldt/rustbook
[INFO] finished tweaking git repo https://github.com/dansaldt/rustbook
[INFO] tweaked toml for git repo https://github.com/dansaldt/rustbook written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] crate git repo https://github.com/dansaldt/rustbook already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+33fdb797f59421c7bbecaa4588ed5d7a31a9494a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+33fdb797f59421c7bbecaa4588ed5d7a31a9494a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 546aff4108c6f07642f0e97f9b584e4dc623da7e48002832b7285aa52afb108b
[INFO] running `Command { std: "docker" "start" "-a" "546aff4108c6f07642f0e97f9b584e4dc623da7e48002832b7285aa52afb108b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "546aff4108c6f07642f0e97f9b584e4dc623da7e48002832b7285aa52afb108b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "546aff4108c6f07642f0e97f9b584e4dc623da7e48002832b7285aa52afb108b", kill_on_drop: false }`
[INFO] [stdout] 546aff4108c6f07642f0e97f9b584e4dc623da7e48002832b7285aa52afb108b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+33fdb797f59421c7bbecaa4588ed5d7a31a9494a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7e65fd43c36f6a27913887c6880871c704e3985958a8c20c5101535a237c3f2a
[INFO] running `Command { std: "docker" "start" "-a" "7e65fd43c36f6a27913887c6880871c704e3985958a8c20c5101535a237c3f2a", kill_on_drop: false }`
[INFO] [stderr]     Checking oop v0.1.0 (/opt/rustwide/workdir/oop)
[INFO] [stderr]     Checking rust_book v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking generics-traits-lifetimes v0.1.0 (/opt/rustwide/workdir/generics-traits-lifetimes)
[INFO] [stderr]     Checking err-handling v0.1.0 (/opt/rustwide/workdir/err-handling)
[INFO] [stderr]     Checking closures v0.1.0 (/opt/rustwide/workdir/closures)
[INFO] [stderr]     Checking restaurant v0.1.0 (/opt/rustwide/workdir/restaurant)
[INFO] [stdout] warning: function is never used: `simple_example`
[INFO] [stdout]  --> err-handling/src/main.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn simple_example () {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer`
[INFO] [stdout]   --> generics-traits-lifetimes/src/main.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let integer = Point { x: 5, y: 10 };
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `float`
[INFO] [stdout]   --> generics-traits-lifetimes/src/main.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let float = Point { x: 1.0, y: 4.0 };
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_float`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer_and_float`
[INFO] [stdout]   --> generics-traits-lifetimes/src/main.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let integer_and_float = Point { x:5, y:4.0 };
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer_and_float`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `x`
[INFO] [stdout]   --> generics-traits-lifetimes/src/main.rs:33:5
[INFO] [stdout]    |
[INFO] [stdout] 33 |     x: T,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `y`
[INFO] [stdout]   --> generics-traits-lifetimes/src/main.rs:34:5
[INFO] [stdout]    |
[INFO] [stdout] 34 |     y: U,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v1`
[INFO] [stdout]  --> src/ch8/ch-8.1-vector.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let v1 = vec![1, 2, 3];
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_v1`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]  --> generics-traits-lifetimes/src/lifetimes.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 |     if (x.len() > y.len()) {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item1`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:63:17
[INFO] [stdout]    |
[INFO] [stdout] 63 | pub fn notify3 (item1: &impl Summary, item2: &impl Summary) {
[INFO] [stdout]    |                 ^^^^^ help: if this is intentional, prefix it with an underscore: `_item1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/ch8/ch-8.1-vector.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |         let v = vec![1, 2, 3];
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:63:39
[INFO] [stdout]    |
[INFO] [stdout] 63 | pub fn notify3 (item1: &impl Summary, item2: &impl Summary) {
[INFO] [stdout]    |                                       ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `row`
[INFO] [stdout]   --> src/ch8/ch-8.1-vector.rs:81:13
[INFO] [stdout]    |
[INFO] [stdout] 81 |         let row = vec![
[INFO] [stdout]    |             ^^^ help: if this is intentional, prefix it with an underscore: `_row`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item1`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:67:29
[INFO] [stdout]    |
[INFO] [stdout] 67 | pub fn notify4<T: Summary> (item1: &T, item2: &T) {
[INFO] [stdout]    |                             ^^^^^ help: if this is intentional, prefix it with an underscore: `_item1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:67:40
[INFO] [stdout]    |
[INFO] [stdout] 67 | pub fn notify4<T: Summary> (item1: &T, item2: &T) {
[INFO] [stdout]    |                                        ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:72:17
[INFO] [stdout]    |
[INFO] [stdout] 72 | pub fn notify5 (item: &(impl Summary + Display)) {
[INFO] [stdout]    |                 ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:75:40
[INFO] [stdout]    |
[INFO] [stdout] 75 | pub fn notify6 <T: Summary + Display> (item: &T) {
[INFO] [stdout]    |                                        ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:80:56
[INFO] [stdout]    |
[INFO] [stdout] 80 | fn some_function<T: Display + Clone, U: Clone + Debug>(t: &T, u: &U) -> i32 {
[INFO] [stdout]    |                                                        ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:80:63
[INFO] [stdout]    |
[INFO] [stdout] 80 | fn some_function<T: Display + Clone, U: Clone + Debug>(t: &T, u: &U) -> i32 {
[INFO] [stdout]    |                                                               ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:84:26
[INFO] [stdout]    |
[INFO] [stdout] 84 | fn some_function2<T, U> (t: &T, u: &U) -> i32
[INFO] [stdout]    |                          ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:84:33
[INFO] [stdout]    |
[INFO] [stdout] 84 | fn some_function2<T, U> (t: &T, u: &U) -> i32
[INFO] [stdout]    |                                 ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/ch8/ch-8.1-vector.rs:45:13
[INFO] [stdout]    |
[INFO] [stdout] 45 |         let mut v = vec![1, 2, 3, 4, 5];
[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: function is never used: `some_function`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:80:4
[INFO] [stdout]    |
[INFO] [stdout] 80 | fn some_function<T: Display + Clone, U: Clone + Debug>(t: &T, u: &U) -> i32 {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `some_function2`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:84:4
[INFO] [stdout]    |
[INFO] [stdout] 84 | fn some_function2<T, U> (t: &T, u: &U) -> i32
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `returns_summarizable`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:92:4
[INFO] [stdout]    |
[INFO] [stdout] 92 | fn returns_summarizable() -> impl Summary {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Pair`
[INFO] [stdout]    --> generics-traits-lifetimes/src/traits.rs:113:8
[INFO] [stdout]     |
[INFO] [stdout] 113 | struct Pair <T> {
[INFO] [stdout]     |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]    --> generics-traits-lifetimes/src/traits.rs:119:8
[INFO] [stdout]     |
[INFO] [stdout] 119 |     fn new (x: T, y: T) -> Self {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `cmp_display`
[INFO] [stdout]    --> generics-traits-lifetimes/src/traits.rs:125:8
[INFO] [stdout]     |
[INFO] [stdout] 125 |     fn cmp_display(&self) {
[INFO] [stdout]     |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:149:9
[INFO] [stdout]     |
[INFO] [stdout] 149 |     let x: i8 = 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: `y`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:150:9
[INFO] [stdout]     |
[INFO] [stdout] 150 |     let y: Option<i8> = Some(5);
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let f = match f {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |     let f = File::open("hello.txt").unwrap_or_else(|error| {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let f = File::open("hello.txt").unwrap();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:41:9
[INFO] [stdout]    |
[INFO] [stdout] 41 |     let f = File::open("hello.txt").expect("Failed to open hello.txt");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `res`
[INFO] [stdout]    --> err-handling/src/recoverable-errors.rs:102:9
[INFO] [stdout]     |
[INFO] [stdout] 102 |     let res = read_username_from_file_v3().expect("Failed to read username");
[INFO] [stdout]     |         ^^^ help: if this is intentional, prefix it with an underscore: `_res`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open_or_create_file`
[INFO] [stdout]  --> err-handling/src/recoverable-errors.rs:7:4
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn open_or_create_file () {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open_or_create_file_more_concise_impl`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:24:4
[INFO] [stdout]    |
[INFO] [stdout] 24 | fn open_or_create_file_more_concise_impl () {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open_file_unwrap`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:36:4
[INFO] [stdout]    |
[INFO] [stdout] 36 | fn open_file_unwrap() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open_file_expect`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:40:4
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn open_file_expect() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_username_from_file`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:44:4
[INFO] [stdout]    |
[INFO] [stdout] 44 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_username_from_file_v2`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:62:4
[INFO] [stdout]    |
[INFO] [stdout] 62 | fn read_username_from_file_v2() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_username_from_file_v4`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:94:4
[INFO] [stdout]    |
[INFO] [stdout] 94 | fn read_username_from_file_v4() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `kind`
[INFO] [stdout]   --> src/ch6/ch-6.1-defining-an-enum.rs:20:5
[INFO] [stdout]    |
[INFO] [stdout] 20 |     kind: IpAddrKind,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Ipv4Addr`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:100:8
[INFO] [stdout]     |
[INFO] [stdout] 100 | struct Ipv4Addr {
[INFO] [stdout]     |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Ipv6Addr`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:104:8
[INFO] [stdout]     |
[INFO] [stdout] 104 | struct Ipv6Addr {
[INFO] [stdout]     |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `IpAddr4`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:108:6
[INFO] [stdout]     |
[INFO] [stdout] 108 | enum IpAddr4 {
[INFO] [stdout]     |      ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Quit`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:115:5
[INFO] [stdout]     |
[INFO] [stdout] 115 |     Quit,                       // normal enum, has not data associated with it atall
[INFO] [stdout]     |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Move`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:116:5
[INFO] [stdout]     |
[INFO] [stdout] 116 |     Move { x: i32, y: i32 },    // enum with anonymous struct type
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `ChangeColor`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:118:5
[INFO] [stdout]     |
[INFO] [stdout] 118 |     ChangeColor(i32, i32, i32), // enum with tuple type of three i32 values
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `QuitMessage`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:121:8
[INFO] [stdout]     |
[INFO] [stdout] 121 | struct QuitMessage;
[INFO] [stdout]     |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `MoveMessage`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:122:8
[INFO] [stdout]     |
[INFO] [stdout] 122 | struct MoveMessage {
[INFO] [stdout]     |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `WriteMessage`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:126:8
[INFO] [stdout]     |
[INFO] [stdout] 126 | struct WriteMessage(String); // tuple struct
[INFO] [stdout]     |        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `ChangeColorMessage`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:127:8
[INFO] [stdout]     |
[INFO] [stdout] 127 | struct ChangeColorMessage(i32, i32, i32); // tuple struct
[INFO] [stdout]     |        ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Message2`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:129:6
[INFO] [stdout]     |
[INFO] [stdout] 129 | enum Message2 {
[INFO] [stdout]     |      ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Diamond`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:164:5
[INFO] [stdout]     |
[INFO] [stdout] 164 |     Diamond,
[INFO] [stdout]     |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Spade`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:165:5
[INFO] [stdout]     |
[INFO] [stdout] 165 |     Spade,
[INFO] [stdout]     |     ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Club`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:166:5
[INFO] [stdout]     |
[INFO] [stdout] 166 |     Club,
[INFO] [stdout]     |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 16 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 12 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v1`
[INFO] [stdout]  --> src/ch8/ch-8.1-vector.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let v1 = vec![1, 2, 3];
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_v1`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/ch8/ch-8.1-vector.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |         let v = vec![1, 2, 3];
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `row`
[INFO] [stdout]   --> src/ch8/ch-8.1-vector.rs:81:13
[INFO] [stdout]    |
[INFO] [stdout] 81 |         let row = vec![
[INFO] [stdout]    |             ^^^ help: if this is intentional, prefix it with an underscore: `_row`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/ch8/ch-8.1-vector.rs:45:13
[INFO] [stdout]    |
[INFO] [stdout] 45 |         let mut v = vec![1, 2, 3, 4, 5];
[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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]  --> generics-traits-lifetimes/src/lifetimes.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 |     if (x.len() > y.len()) {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `username`
[INFO] [stdout]  --> src/ch5/ch-5.1-defining-instantiating-structs.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 |     username: String,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `username`
[INFO] [stdout]  --> src/ch5/ch-5.1-defining-instantiating-structs.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 |     username: String,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `sign_in_count`
[INFO] [stdout]  --> src/ch5/ch-5.1-defining-instantiating-structs.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     sign_in_count: u64,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `active`
[INFO] [stdout]  --> src/ch5/ch-5.1-defining-instantiating-structs.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 |     active: bool,
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `sign_in_count`
[INFO] [stdout]  --> src/ch5/ch-5.1-defining-instantiating-structs.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     sign_in_count: u64,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 17 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `active`
[INFO] [stdout]  --> src/ch5/ch-5.1-defining-instantiating-structs.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 |     active: bool,
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `simple_example`
[INFO] [stdout]  --> err-handling/src/main.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn simple_example () {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item1`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:63:17
[INFO] [stdout]    |
[INFO] [stdout] 63 | pub fn notify3 (item1: &impl Summary, item2: &impl Summary) {
[INFO] [stdout]    |                 ^^^^^ help: if this is intentional, prefix it with an underscore: `_item1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer`
[INFO] [stdout]   --> generics-traits-lifetimes/src/main.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let integer = Point { x: 5, y: 10 };
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:63:39
[INFO] [stdout]    |
[INFO] [stdout] 63 | pub fn notify3 (item1: &impl Summary, item2: &impl Summary) {
[INFO] [stdout]    |                                       ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item1`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:67:29
[INFO] [stdout]    |
[INFO] [stdout] 67 | pub fn notify4<T: Summary> (item1: &T, item2: &T) {
[INFO] [stdout]    |                             ^^^^^ help: if this is intentional, prefix it with an underscore: `_item1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:67:40
[INFO] [stdout]    |
[INFO] [stdout] 67 | pub fn notify4<T: Summary> (item1: &T, item2: &T) {
[INFO] [stdout]    |                                        ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:72:17
[INFO] [stdout]    |
[INFO] [stdout] 72 | pub fn notify5 (item: &(impl Summary + Display)) {
[INFO] [stdout]    |                 ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:75:40
[INFO] [stdout]    |
[INFO] [stdout] 75 | pub fn notify6 <T: Summary + Display> (item: &T) {
[INFO] [stdout]    |                                        ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:80:56
[INFO] [stdout]    |
[INFO] [stdout] 80 | fn some_function<T: Display + Clone, U: Clone + Debug>(t: &T, u: &U) -> i32 {
[INFO] [stdout]    |                                                        ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:80:63
[INFO] [stdout]    |
[INFO] [stdout] 80 | fn some_function<T: Display + Clone, U: Clone + Debug>(t: &T, u: &U) -> i32 {
[INFO] [stdout]    |                                                               ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:84:26
[INFO] [stdout]    |
[INFO] [stdout] 84 | fn some_function2<T, U> (t: &T, u: &U) -> i32
[INFO] [stdout]    |                          ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:84:33
[INFO] [stdout]    |
[INFO] [stdout] 84 | fn some_function2<T, U> (t: &T, u: &U) -> i32
[INFO] [stdout]    |                                 ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `float`
[INFO] [stdout]   --> generics-traits-lifetimes/src/main.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let float = Point { x: 1.0, y: 4.0 };
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_float`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer_and_float`
[INFO] [stdout]   --> generics-traits-lifetimes/src/main.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let integer_and_float = Point { x:5, y:4.0 };
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer_and_float`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `x`
[INFO] [stdout]   --> generics-traits-lifetimes/src/main.rs:33:5
[INFO] [stdout]    |
[INFO] [stdout] 33 |     x: T,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six`
[INFO] [stdout]   --> src/ch6/ch-6.2-match-control-flow-operator.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let six = plus_one(five);
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_six`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `none`
[INFO] [stdout]   --> src/ch6/ch-6.2-match-control-flow-operator.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let none = plus_one(None);
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_none`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `some_function`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:80:4
[INFO] [stdout]    |
[INFO] [stdout] 80 | fn some_function<T: Display + Clone, U: Clone + Debug>(t: &T, u: &U) -> i32 {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `y`
[INFO] [stdout]   --> generics-traits-lifetimes/src/main.rs:34:5
[INFO] [stdout]    |
[INFO] [stdout] 34 |     y: U,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `some_function2`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:84:4
[INFO] [stdout]    |
[INFO] [stdout] 84 | fn some_function2<T, U> (t: &T, u: &U) -> i32
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `returns_summarizable`
[INFO] [stdout]   --> generics-traits-lifetimes/src/traits.rs:92:4
[INFO] [stdout]    |
[INFO] [stdout] 92 | fn returns_summarizable() -> impl Summary {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Pair`
[INFO] [stdout]    --> generics-traits-lifetimes/src/traits.rs:113:8
[INFO] [stdout]     |
[INFO] [stdout] 113 | struct Pair <T> {
[INFO] [stdout]     |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]    --> generics-traits-lifetimes/src/traits.rs:119:8
[INFO] [stdout]     |
[INFO] [stdout] 119 |     fn new (x: T, y: T) -> Self {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Alabama`
[INFO] [stdout]   --> src/ch6/ch-6.2-match-control-flow-operator.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     Alabama,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Penny`
[INFO] [stdout]   --> src/ch6/ch-6.2-match-control-flow-operator.rs:19:5
[INFO] [stdout]    |
[INFO] [stdout] 19 |     Penny,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `cmp_display`
[INFO] [stdout]    --> generics-traits-lifetimes/src/traits.rs:125:8
[INFO] [stdout]     |
[INFO] [stdout] 125 |     fn cmp_display(&self) {
[INFO] [stdout]     |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Nickel`
[INFO] [stdout]   --> src/ch6/ch-6.2-match-control-flow-operator.rs:20:5
[INFO] [stdout]    |
[INFO] [stdout] 20 |     Nickel,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Dime`
[INFO] [stdout]   --> src/ch6/ch-6.2-match-control-flow-operator.rs:21:5
[INFO] [stdout]    |
[INFO] [stdout] 21 |     Dime,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused doc comment
[INFO] [stdout]   --> closures/src/main.rs:46:5
[INFO] [stdout]    |
[INFO] [stdout] 46 | /     /// to explicitly annotate the types used on the closure, we can define like the following
[INFO] [stdout] 47 | |     /// `let expensive_closure = |num: u32| -> u32 {};`
[INFO] [stdout] 48 | |     /// however it's not necessary
[INFO] [stdout] 49 | |     /// the catch to define closure without annotation is that the closure need to be used for it-
[INFO] [stdout] 50 | |     ///   to be able to be compiled. This is because the compiler needs to infer the types and-
[INFO] [stdout] 51 | |     ///   it's impossible to infer the type without any usage/call to the closure
[INFO] [stdout]    | |_________________________________________________________________________________^
[INFO] [stdout] 52 | /     let mut expensive_result = Cacher::new(|num| {
[INFO] [stdout] 53 | |         println!("calculating slowly");
[INFO] [stdout] 54 | |         thread::sleep(Duration::from_secs(2));
[INFO] [stdout] 55 | |         num
[INFO] [stdout] 56 | |     });
[INFO] [stdout]    | |_______- rustdoc does not generate documentation for statements
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_doc_comments)]` on by default
[INFO] [stdout]    = help: use `//` for a plain comment
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0106]: missing lifetime specifier
[INFO] [stdout]   --> src/main.rs:32:17
[INFO] [stdout]    |
[INFO] [stdout] 32 | fn dangle () -> &String
[INFO] [stdout]    |                 ^ expected named lifetime parameter
[INFO] [stdout]    |
[INFO] [stdout]    = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
[INFO] [stdout] help: consider using the `'static` lifetime
[INFO] [stdout]    |
[INFO] [stdout] 32 | fn dangle () -> &'static String
[INFO] [stdout]    |                 ~~~~~~~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_book` due to 2 previous errors
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] For more information about this error, try `rustc --explain E0106`.
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let f = match f {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |     let f = File::open("hello.txt").unwrap_or_else(|error| {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let f = File::open("hello.txt").unwrap();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:41:9
[INFO] [stdout]    |
[INFO] [stdout] 41 |     let f = File::open("hello.txt").expect("Failed to open hello.txt");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `res`
[INFO] [stdout]    --> err-handling/src/recoverable-errors.rs:102:9
[INFO] [stdout]     |
[INFO] [stdout] 102 |     let res = read_username_from_file_v3().expect("Failed to read username");
[INFO] [stdout]     |         ^^^ help: if this is intentional, prefix it with an underscore: `_res`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open_or_create_file`
[INFO] [stdout]  --> err-handling/src/recoverable-errors.rs:7:4
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn open_or_create_file () {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open_or_create_file_more_concise_impl`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:24:4
[INFO] [stdout]    |
[INFO] [stdout] 24 | fn open_or_create_file_more_concise_impl () {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open_file_unwrap`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:36:4
[INFO] [stdout]    |
[INFO] [stdout] 36 | fn open_file_unwrap() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open_file_expect`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:40:4
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn open_file_expect() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_username_from_file`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:44:4
[INFO] [stdout]    |
[INFO] [stdout] 44 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_username_from_file_v2`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:62:4
[INFO] [stdout]    |
[INFO] [stdout] 62 | fn read_username_from_file_v2() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_username_from_file_v4`
[INFO] [stdout]   --> err-handling/src/recoverable-errors.rs:94:4
[INFO] [stdout]    |
[INFO] [stdout] 94 | fn read_username_from_file_v4() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:29:9
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let word = first_word_no_slice(&s); // word will get the valud 5
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let slice = &a[1..3];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |     let hello = &s[..5]; // this is equal to &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/ch4/the-slice-type.rs:89:9
[INFO] [stdout]    |
[INFO] [stdout] 89 |     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: function is never used: `shoe_in_my_size`
[INFO] [stdout]  --> closures/src/filters.rs:8:4
[INFO] [stdout]   |
[INFO] [stdout] 8 | fn shoe_in_my_size(shoes: Vec<Shoe>, shoe_size: u32) -> Vec<Shoe> {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]  --> closures/src/counter.rs:7:8
[INFO] [stdout]   |
[INFO] [stdout] 7 |     fn new() -> Counter {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `simulated_expensive_calculation`
[INFO] [stdout]   --> closures/src/main.rs:39:4
[INFO] [stdout]    |
[INFO] [stdout] 39 | fn simulated_expensive_calculation(intensity: u32) -> u32 {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `call`
[INFO] [stdout]    --> closures/src/main.rs:119:4
[INFO] [stdout]     |
[INFO] [stdout] 119 | fn call(number: &str) -> &str {
[INFO] [stdout]     |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0106]: missing lifetime specifier
[INFO] [stdout]   --> src/main.rs:32:17
[INFO] [stdout]    |
[INFO] [stdout] 32 | fn dangle () -> &String
[INFO] [stdout]    |                 ^ expected named lifetime parameter
[INFO] [stdout]    |
[INFO] [stdout]    = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
[INFO] [stdout] help: consider using the `'static` lifetime
[INFO] [stdout]    |
[INFO] [stdout] 32 | fn dangle () -> &'static String
[INFO] [stdout]    |                 ~~~~~~~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0106`.
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let mut s = String::from("hello world");
[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: function is never used: `first_word_no_slice`
[INFO] [stdout]  --> src/ch4/the-slice-type.rs:2:4
[INFO] [stdout]   |
[INFO] [stdout] 2 | fn first_word_no_slice(s: &String) -> usize {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `before_using_slice`
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:26:4
[INFO] [stdout]    |
[INFO] [stdout] 26 | fn before_using_slice () {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `after_using_slice`
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:37:4
[INFO] [stdout]    |
[INFO] [stdout] 37 | fn after_using_slice () {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `other_slices`
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:70:4
[INFO] [stdout]    |
[INFO] [stdout] 70 | fn other_slices () {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `slice_example`
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:83:4
[INFO] [stdout]    |
[INFO] [stdout] 83 | fn slice_example () {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 12 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 16 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six`
[INFO] [stdout]   --> src/ch6/ch-6.2-match-control-flow-operator.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let six = plus_one(five);
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_six`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `none`
[INFO] [stdout]   --> src/ch6/ch-6.2-match-control-flow-operator.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let none = plus_one(None);
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_none`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:149:9
[INFO] [stdout]     |
[INFO] [stdout] 149 |     let x: i8 = 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: `y`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:150:9
[INFO] [stdout]     |
[INFO] [stdout] 150 |     let y: Option<i8> = Some(5);
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:29:9
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let word = first_word_no_slice(&s); // word will get the valud 5
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let slice = &a[1..3];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |     let hello = &s[..5]; // this is equal to &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/ch4/the-slice-type.rs:89:9
[INFO] [stdout]    |
[INFO] [stdout] 89 |     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: variable does not need to be mutable
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let mut s = String::from("hello world");
[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: field is never read: `kind`
[INFO] [stdout]   --> src/ch6/ch-6.1-defining-an-enum.rs:20:5
[INFO] [stdout]    |
[INFO] [stdout] 20 |     kind: IpAddrKind,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Ipv4Addr`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:100:8
[INFO] [stdout]     |
[INFO] [stdout] 100 | struct Ipv4Addr {
[INFO] [stdout]     |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Ipv6Addr`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:104:8
[INFO] [stdout]     |
[INFO] [stdout] 104 | struct Ipv6Addr {
[INFO] [stdout]     |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `IpAddr4`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:108:6
[INFO] [stdout]     |
[INFO] [stdout] 108 | enum IpAddr4 {
[INFO] [stdout]     |      ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Quit`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:115:5
[INFO] [stdout]     |
[INFO] [stdout] 115 |     Quit,                       // normal enum, has not data associated with it atall
[INFO] [stdout]     |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Move`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:116:5
[INFO] [stdout]     |
[INFO] [stdout] 116 |     Move { x: i32, y: i32 },    // enum with anonymous struct type
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `ChangeColor`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:118:5
[INFO] [stdout]     |
[INFO] [stdout] 118 |     ChangeColor(i32, i32, i32), // enum with tuple type of three i32 values
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `QuitMessage`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:121:8
[INFO] [stdout]     |
[INFO] [stdout] 121 | struct QuitMessage;
[INFO] [stdout]     |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `MoveMessage`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:122:8
[INFO] [stdout]     |
[INFO] [stdout] 122 | struct MoveMessage {
[INFO] [stdout]     |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `WriteMessage`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:126:8
[INFO] [stdout]     |
[INFO] [stdout] 126 | struct WriteMessage(String); // tuple struct
[INFO] [stdout]     |        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `ChangeColorMessage`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:127:8
[INFO] [stdout]     |
[INFO] [stdout] 127 | struct ChangeColorMessage(i32, i32, i32); // tuple struct
[INFO] [stdout]     |        ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Message2`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:129:6
[INFO] [stdout]     |
[INFO] [stdout] 129 | enum Message2 {
[INFO] [stdout]     |      ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Diamond`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:164:5
[INFO] [stdout]     |
[INFO] [stdout] 164 |     Diamond,
[INFO] [stdout]     |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Spade`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:165:5
[INFO] [stdout]     |
[INFO] [stdout] 165 |     Spade,
[INFO] [stdout]     |     ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Club`
[INFO] [stdout]    --> src/ch6/ch-6.1-defining-an-enum.rs:166:5
[INFO] [stdout]     |
[INFO] [stdout] 166 |     Club,
[INFO] [stdout]     |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `first_word_no_slice`
[INFO] [stdout]  --> src/ch4/the-slice-type.rs:2:4
[INFO] [stdout]   |
[INFO] [stdout] 2 | fn first_word_no_slice(s: &String) -> usize {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Alabama`
[INFO] [stdout]   --> src/ch6/ch-6.2-match-control-flow-operator.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     Alabama,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Penny`
[INFO] [stdout]   --> src/ch6/ch-6.2-match-control-flow-operator.rs:19:5
[INFO] [stdout]    |
[INFO] [stdout] 19 |     Penny,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Nickel`
[INFO] [stdout]   --> src/ch6/ch-6.2-match-control-flow-operator.rs:20:5
[INFO] [stdout]    |
[INFO] [stdout] 20 |     Nickel,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Dime`
[INFO] [stdout]   --> src/ch6/ch-6.2-match-control-flow-operator.rs:21:5
[INFO] [stdout]    |
[INFO] [stdout] 21 |     Dime,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `before_using_slice`
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:26:4
[INFO] [stdout]    |
[INFO] [stdout] 26 | fn before_using_slice () {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `after_using_slice`
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:37:4
[INFO] [stdout]    |
[INFO] [stdout] 37 | fn after_using_slice () {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `other_slices`
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:70:4
[INFO] [stdout]    |
[INFO] [stdout] 70 | fn other_slices () {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `slice_example`
[INFO] [stdout]   --> src/ch4/the-slice-type.rs:83:4
[INFO] [stdout]    |
[INFO] [stdout] 83 | fn slice_example () {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 17 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused doc comment
[INFO] [stdout]   --> closures/src/main.rs:46:5
[INFO] [stdout]    |
[INFO] [stdout] 46 | /     /// to explicitly annotate the types used on the closure, we can define like the following
[INFO] [stdout] 47 | |     /// `let expensive_closure = |num: u32| -> u32 {};`
[INFO] [stdout] 48 | |     /// however it's not necessary
[INFO] [stdout] 49 | |     /// the catch to define closure without annotation is that the closure need to be used for it-
[INFO] [stdout] 50 | |     ///   to be able to be compiled. This is because the compiler needs to infer the types and-
[INFO] [stdout] 51 | |     ///   it's impossible to infer the type without any usage/call to the closure
[INFO] [stdout]    | |_________________________________________________________________________________^
[INFO] [stdout] 52 | /     let mut expensive_result = Cacher::new(|num| {
[INFO] [stdout] 53 | |         println!("calculating slowly");
[INFO] [stdout] 54 | |         thread::sleep(Duration::from_secs(2));
[INFO] [stdout] 55 | |         num
[INFO] [stdout] 56 | |     });
[INFO] [stdout]    | |_______- rustdoc does not generate documentation for statements
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_doc_comments)]` on by default
[INFO] [stdout]    = help: use `//` for a plain comment
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v1`
[INFO] [stdout]   --> closures/src/main.rs:81:9
[INFO] [stdout]    |
[INFO] [stdout] 81 |     let v1 = c.value(1);
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_v1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `simulated_expensive_calculation`
[INFO] [stdout]   --> closures/src/main.rs:39:4
[INFO] [stdout]    |
[INFO] [stdout] 39 | fn simulated_expensive_calculation(intensity: u32) -> u32 {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: module `Test` should have a snake case name
[INFO] [stdout]   --> closures/src/counter.rs:26:5
[INFO] [stdout]    |
[INFO] [stdout] 26 | mod Test {
[INFO] [stdout]    |     ^^^^ help: convert the identifier to snake case: `test`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "7e65fd43c36f6a27913887c6880871c704e3985958a8c20c5101535a237c3f2a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7e65fd43c36f6a27913887c6880871c704e3985958a8c20c5101535a237c3f2a", kill_on_drop: false }`
[INFO] [stdout] 7e65fd43c36f6a27913887c6880871c704e3985958a8c20c5101535a237c3f2a