[INFO] cloning repository https://github.com/dev-chee/beginning_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/dev-chee/beginning_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdev-chee%2Fbeginning_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdev-chee%2Fbeginning_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 77bb479c689cf5590a76bf3b1f67a384126ec8ac
[INFO] checking dev-chee/beginning_rust against try#f47dd4da3ae8c32c9e65d307bfe640b143e674df for pr-77526
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdev-chee%2Fbeginning_rust" "/workspace/builds/worker-9/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/dev-chee/beginning_rust on toolchain f47dd4da3ae8c32c9e65d307bfe640b143e674df
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/dev-chee/beginning_rust
[INFO] finished tweaking git repo https://github.com/dev-chee/beginning_rust
[INFO] tweaked toml for git repo https://github.com/dev-chee/beginning_rust written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/dev-chee/beginning_rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 95631bc7893b4ace527e7e8de29a1941c4304e7654ea25e1612dc27a15419c42
[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" "95631bc7893b4ace527e7e8de29a1941c4304e7654ea25e1612dc27a15419c42", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "95631bc7893b4ace527e7e8de29a1941c4304e7654ea25e1612dc27a15419c42", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "95631bc7893b4ace527e7e8de29a1941c4304e7654ea25e1612dc27a15419c42", kill_on_drop: false }`
[INFO] [stdout] 95631bc7893b4ace527e7e8de29a1941c4304e7654ea25e1612dc27a15419c42
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ded3a2e05f9b38abd72a937afea95a61f5e0510971f567cd48a1aea30ed666ec
[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" "ded3a2e05f9b38abd72a937afea95a61f5e0510971f567cd48a1aea30ed666ec", kill_on_drop: false }`
[INFO] [stderr]     Checking beginning_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary braces around block return value
[INFO] [stdout]    --> src/bin/ch04.rs:120:17
[INFO] [stdout]     |
[INFO] [stdout] 120 |                 {{ }}
[INFO] [stdout]     |                 ^^^^^ help: remove these braces
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_braces)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `xi`
[INFO] [stdout]    --> src/bin/ch04.rs:129:13
[INFO] [stdout]     |
[INFO] [stdout] 129 |         let xi = 10;
[INFO] [stdout]     |             ^^ help: if this is intentional, prefix it with an underscore: `_xi`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `em_e`
[INFO] [stdout]   --> src/bin/ch10.rs:79:9
[INFO] [stdout]    |
[INFO] [stdout] 79 |     let em_e = Em::<i32>::E;
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_em_e`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `c`
[INFO] [stdout]   --> src/bin/ch10.rs:26:5
[INFO] [stdout]    |
[INFO] [stdout] 26 |     c: char,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `n1`
[INFO] [stdout]   --> src/bin/ch10.rs:27:5
[INFO] [stdout]    |
[INFO] [stdout] 27 |     n1: T1,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `n2`
[INFO] [stdout]   --> src/bin/ch10.rs:28:5
[INFO] [stdout]    |
[INFO] [stdout] 28 |     n2: T2,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `continent` is never read
[INFO] [stdout]   --> src/bin/ch07.rs:44:13
[INFO] [stdout]    |
[INFO] [stdout] 44 |             continent = Continent::Asia;
[INFO] [stdout]    |             ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/bin/ch07.rs:48:17
[INFO] [stdout]    |
[INFO] [stdout] 48 |             let a = 8;
[INFO] [stdout]    |                 ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `outcome`
[INFO] [stdout]    --> src/bin/ch07.rs:118:9
[INFO] [stdout]     |
[INFO] [stdout] 118 |     let outcome = Result::Failure(1200, 'X');
[INFO] [stdout]     |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_outcome`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Africa`
[INFO] [stdout]   --> src/bin/ch07.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |         Africa,
[INFO] [stdout]    |         ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `America`
[INFO] [stdout]   --> src/bin/ch07.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |         America,
[INFO] [stdout]    |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Oceania`
[INFO] [stdout]   --> src/bin/ch07.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |         Oceania,
[INFO] [stdout]    |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `West`
[INFO] [stdout]   --> src/bin/ch07.rs:62:40
[INFO] [stdout]    |
[INFO] [stdout] 62 |     enum CardinalPoint { North, South, West, East };
[INFO] [stdout]    |                                        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `East`
[INFO] [stdout]   --> src/bin/ch07.rs:62:46
[INFO] [stdout]    |
[INFO] [stdout] 62 |     enum CardinalPoint { North, South, West, East };
[INFO] [stdout]    |                                              ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Uncertainty`
[INFO] [stdout]    --> src/bin/ch07.rs:115:9
[INFO] [stdout]     |
[INFO] [stdout] 115 |         Uncertainty,
[INFO] [stdout]     |         ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 9 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `process`
[INFO] [stdout]  --> src/bin/ch17.rs:3:16
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::{env, process, io};
[INFO] [stdout]   |                ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `f1`
[INFO] [stdout]  --> src/bin/ch17.rs:7:4
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn f1(x: i32) -> Result<i32, String> {
[INFO] [stdout]   |    ^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `f2`
[INFO] [stdout]   --> src/bin/ch17.rs:15:4
[INFO] [stdout]    |
[INFO] [stdout] 15 | fn f2(x: i32) -> Result<i32, String> {
[INFO] [stdout]    |    ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `f3`
[INFO] [stdout]   --> src/bin/ch17.rs:23:4
[INFO] [stdout]    |
[INFO] [stdout] 23 | fn f3(x: i32) -> Result<i32, String> {
[INFO] [stdout]    |    ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `f4`
[INFO] [stdout]   --> src/bin/ch17.rs:31:4
[INFO] [stdout]    |
[INFO] [stdout] 31 | fn f4(x: i32) -> Result<i32, String> {
[INFO] [stdout]    |    ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `f`
[INFO] [stdout]   --> src/bin/ch17.rs:39:4
[INFO] [stdout]    |
[INFO] [stdout] 39 | fn f(x: i32) -> Result<i32, String> {
[INFO] [stdout]    |    ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `of1`
[INFO] [stdout]   --> src/bin/ch17.rs:57:4
[INFO] [stdout]    |
[INFO] [stdout] 57 | fn of1(x: i32) -> Option<i32> {
[INFO] [stdout]    |    ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `of2`
[INFO] [stdout]   --> src/bin/ch17.rs:65:4
[INFO] [stdout]    |
[INFO] [stdout] 65 | fn of2(x: i32) -> Option<i32> {
[INFO] [stdout]    |    ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `of`
[INFO] [stdout]   --> src/bin/ch17.rs:73:4
[INFO] [stdout]    |
[INFO] [stdout] 73 | fn of(x: i32) -> Option<i32> {
[INFO] [stdout]    |    ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `copy_file`
[INFO] [stdout]   --> src/bin/ch17.rs:77:4
[INFO] [stdout]    |
[INFO] [stdout] 77 | fn copy_file(from: &str, to: &str) {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `S`
[INFO] [stdout]   --> src/bin/ch12.rs:41:15
[INFO] [stdout]    |
[INFO] [stdout] 41 |     enum Em { S, W };
[INFO] [stdout]    |               ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `W`
[INFO] [stdout]   --> src/bin/ch12.rs:41:18
[INFO] [stdout]    |
[INFO] [stdout] 41 |     enum Em { S, W };
[INFO] [stdout]    |                  ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `continent` is never read
[INFO] [stdout]   --> src/bin/ch07.rs:44:13
[INFO] [stdout]    |
[INFO] [stdout] 44 |             continent = Continent::Asia;
[INFO] [stdout]    |             ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/bin/ch07.rs:48:17
[INFO] [stdout]    |
[INFO] [stdout] 48 |             let a = 8;
[INFO] [stdout]    |                 ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `outcome`
[INFO] [stdout]    --> src/bin/ch07.rs:118:9
[INFO] [stdout]     |
[INFO] [stdout] 118 |     let outcome = Result::Failure(1200, 'X');
[INFO] [stdout]     |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_outcome`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Motorcycle`
[INFO] [stdout]   --> src/bin/ch08.rs:47:9
[INFO] [stdout]    |
[INFO] [stdout] 47 |         Motorcycle,
[INFO] [stdout]    |         ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Truck`
[INFO] [stdout]   --> src/bin/ch08.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |         Truck,
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `kind`
[INFO] [stdout]   --> src/bin/ch08.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |         kind: VehicleKind,
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `registration_year`
[INFO] [stdout]   --> src/bin/ch08.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |         registration_year: u16,
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `registration_month`
[INFO] [stdout]   --> src/bin/ch08.rs:55:9
[INFO] [stdout]    |
[INFO] [stdout] 55 |         registration_month: u8,
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `BinaryHeap`, `VecDeque`
[INFO] [stdout]   --> src/bin/ch20.rs:22:24
[INFO] [stdout]    |
[INFO] [stdout] 22 | use std::collections::{VecDeque, BinaryHeap, HashSet, BTreeSet};
[INFO] [stdout]    |                        ^^^^^^^^  ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `elapsed_ms`
[INFO] [stdout]   --> src/bin/ch20.rs:24:4
[INFO] [stdout]    |
[INFO] [stdout] 24 | fn elapsed_ms(t1: Instant, t2: Instant) -> f64 {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `BinaryHeap`, `VecDeque`
[INFO] [stdout]   --> src/bin/ch20.rs:22:24
[INFO] [stdout]    |
[INFO] [stdout] 22 | use std::collections::{VecDeque, BinaryHeap, HashSet, BTreeSet};
[INFO] [stdout]    |                        ^^^^^^^^  ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `elapsed_ms`
[INFO] [stdout]   --> src/bin/ch20.rs:24:4
[INFO] [stdout]    |
[INFO] [stdout] 24 | fn elapsed_ms(t1: Instant, t2: Instant) -> f64 {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/bin/ch22.rs:103:40
[INFO] [stdout]     |
[INFO] [stdout] 103 |     fn fxx<'a>(n: i32, x: &'a Vec<u8>, y: &Vec<u8>) -> &'a u8 {
[INFO] [stdout]     |                                        ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `xf`
[INFO] [stdout]   --> src/bin/ch22.rs:87:8
[INFO] [stdout]    |
[INFO] [stdout] 87 |     fn xf(x: &'static i32) -> &'static 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: `fx`
[INFO] [stdout]   --> src/bin/ch22.rs:91:8
[INFO] [stdout]    |
[INFO] [stdout] 91 |     fn fx<'a, 'b>(x: &'a i32, y: &'b i32) -> (&'b i32, &'a i32) {
[INFO] [stdout]    |        ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `fxx`
[INFO] [stdout]    --> src/bin/ch22.rs:103:8
[INFO] [stdout]     |
[INFO] [stdout] 103 |     fn fxx<'a>(n: i32, x: &'a Vec<u8>, y: &Vec<u8>) -> &'a u8 {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `ff`
[INFO] [stdout]    --> src/bin/ch22.rs:117:8
[INFO] [stdout]     |
[INFO] [stdout] 117 |     fn ff(b: &mut u8) -> &u8 {
[INFO] [stdout]     |        ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/bin/ch22.rs:103:40
[INFO] [stdout]     |
[INFO] [stdout] 103 |     fn fxx<'a>(n: i32, x: &'a Vec<u8>, y: &Vec<u8>) -> &'a u8 {
[INFO] [stdout]     |                                        ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary braces around block return value
[INFO] [stdout]    --> src/bin/ch04.rs:120:17
[INFO] [stdout]     |
[INFO] [stdout] 120 |                 {{ }}
[INFO] [stdout]     |                 ^^^^^ help: remove these braces
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_braces)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `process`
[INFO] [stdout]  --> src/bin/ch17.rs:3:16
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::{env, process, io};
[INFO] [stdout]   |                ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `em_e`
[INFO] [stdout]   --> src/bin/ch10.rs:79:9
[INFO] [stdout]    |
[INFO] [stdout] 79 |     let em_e = Em::<i32>::E;
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_em_e`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `xi`
[INFO] [stdout]    --> src/bin/ch04.rs:129:13
[INFO] [stdout]     |
[INFO] [stdout] 129 |         let xi = 10;
[INFO] [stdout]     |             ^^ help: if this is intentional, prefix it with an underscore: `_xi`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `c`
[INFO] [stdout]   --> src/bin/ch10.rs:26:5
[INFO] [stdout]    |
[INFO] [stdout] 26 |     c: char,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `n1`
[INFO] [stdout]   --> src/bin/ch10.rs:27:5
[INFO] [stdout]    |
[INFO] [stdout] 27 |     n1: T1,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `n2`
[INFO] [stdout]   --> src/bin/ch10.rs:28:5
[INFO] [stdout]    |
[INFO] [stdout] 28 |     n2: T2,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `f1`
[INFO] [stdout]  --> src/bin/ch17.rs:7:4
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn f1(x: i32) -> Result<i32, String> {
[INFO] [stdout]   |    ^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `f2`
[INFO] [stdout]   --> src/bin/ch17.rs:15:4
[INFO] [stdout]    |
[INFO] [stdout] 15 | fn f2(x: i32) -> Result<i32, String> {
[INFO] [stdout]    |    ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `f3`
[INFO] [stdout]   --> src/bin/ch17.rs:23:4
[INFO] [stdout]    |
[INFO] [stdout] 23 | fn f3(x: i32) -> Result<i32, String> {
[INFO] [stdout]    |    ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `f4`
[INFO] [stdout]   --> src/bin/ch17.rs:31:4
[INFO] [stdout]    |
[INFO] [stdout] 31 | fn f4(x: i32) -> Result<i32, String> {
[INFO] [stdout]    |    ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `f`
[INFO] [stdout]   --> src/bin/ch17.rs:39:4
[INFO] [stdout]    |
[INFO] [stdout] 39 | fn f(x: i32) -> Result<i32, String> {
[INFO] [stdout]    |    ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `of1`
[INFO] [stdout]   --> src/bin/ch17.rs:57:4
[INFO] [stdout]    |
[INFO] [stdout] 57 | fn of1(x: i32) -> Option<i32> {
[INFO] [stdout]    |    ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `of2`
[INFO] [stdout]   --> src/bin/ch17.rs:65:4
[INFO] [stdout]    |
[INFO] [stdout] 65 | fn of2(x: i32) -> Option<i32> {
[INFO] [stdout]    |    ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `of`
[INFO] [stdout]   --> src/bin/ch17.rs:73:4
[INFO] [stdout]    |
[INFO] [stdout] 73 | fn of(x: i32) -> Option<i32> {
[INFO] [stdout]    |    ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `copy_file`
[INFO] [stdout]   --> src/bin/ch17.rs:77:4
[INFO] [stdout]    |
[INFO] [stdout] 77 | fn copy_file(from: &str, to: &str) {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.82s
[INFO] running `Command { std: "docker" "inspect" "ded3a2e05f9b38abd72a937afea95a61f5e0510971f567cd48a1aea30ed666ec", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ded3a2e05f9b38abd72a937afea95a61f5e0510971f567cd48a1aea30ed666ec", kill_on_drop: false }`
[INFO] [stdout] ded3a2e05f9b38abd72a937afea95a61f5e0510971f567cd48a1aea30ed666ec