[INFO] cloning repository https://github.com/lazylook2/rust_study
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/lazylook2/rust_study" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flazylook2%2Frust_study", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flazylook2%2Frust_study'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] e091f734aa7eeb5f5f641997026d248ba730361c
[INFO] checking lazylook2/rust_study against try#c8bdaa84ec1b37f18f30375e196a65b7602f3790 for pr-73345
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flazylook2%2Frust_study" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/lazylook2/rust_study on toolchain c8bdaa84ec1b37f18f30375e196a65b7602f3790
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c8bdaa84ec1b37f18f30375e196a65b7602f3790" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/lazylook2/rust_study
[INFO] finished tweaking git repo https://github.com/lazylook2/rust_study
[INFO] tweaked toml for git repo https://github.com/lazylook2/rust_study written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/lazylook2/rust_study already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c8bdaa84ec1b37f18f30375e196a65b7602f3790" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:6c9ffe128752d56c8d75334ed354142a5229917ed99767f56566dd8e857ad726" "/opt/rustwide/cargo-home/bin/cargo" "+c8bdaa84ec1b37f18f30375e196a65b7602f3790" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e2d597e475512813813f4e6960f4ecee99282569be16280230f2d545a2b84b2a
[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" "e2d597e475512813813f4e6960f4ecee99282569be16280230f2d545a2b84b2a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e2d597e475512813813f4e6960f4ecee99282569be16280230f2d545a2b84b2a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e2d597e475512813813f4e6960f4ecee99282569be16280230f2d545a2b84b2a", kill_on_drop: false }`
[INFO] [stdout] e2d597e475512813813f4e6960f4ecee99282569be16280230f2d545a2b84b2a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:6c9ffe128752d56c8d75334ed354142a5229917ed99767f56566dd8e857ad726" "/opt/rustwide/cargo-home/bin/cargo" "+c8bdaa84ec1b37f18f30375e196a65b7602f3790" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d549f70ae038df6c076f92955c9f482aa4f0683d4d06c103363dc7373d3f95b4
[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" "d549f70ae038df6c076f92955c9f482aa4f0683d4d06c103363dc7373d3f95b4", kill_on_drop: false }`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]     Checking rust_study v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused imports: `ErrorKind`, `Error`
[INFO] [stdout]  --> src/error.rs:2:15
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::{ErrorKind, Read, Error};
[INFO] [stdout]   |               ^^^^^^^^^        ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `teacher` should have an upper camel case name
[INFO] [stdout]   --> src/generics_trait.rs:73:15
[INFO] [stdout]    |
[INFO] [stdout] 73 |     pub trait teacher {
[INFO] [stdout]    |               ^^^^^^^ help: convert the identifier to upper camel case: `Teacher`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_camel_case_types)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `ErrorKind`, `Error`
[INFO] [stdout]  --> src/error.rs:2:15
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::{ErrorKind, Read, Error};
[INFO] [stdout]   |               ^^^^^^^^^        ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `teacher` should have an upper camel case name
[INFO] [stdout]   --> src/generics_trait.rs:73:15
[INFO] [stdout]    |
[INFO] [stdout] 73 |     pub trait teacher {
[INFO] [stdout]    |               ^^^^^^^ help: convert the identifier to upper camel case: `Teacher`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_camel_case_types)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/common.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let y = {
[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: unused variable: `number`
[INFO] [stdout]   --> src/common.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let number = if condition {
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user1`
[INFO] [stdout]  --> src/structs.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let user1 = User{
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user2`
[INFO] [stdout]   --> src/structs.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let user2 = User{
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `four`
[INFO] [stdout]  --> src/enum_match.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let four = IpAddKind::V4;
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_four`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `home`
[INFO] [stdout]   --> src/enum_match.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let home = IpAddr{ kind: IpAddKind::V4, address: String::from("127.0.0.1") };
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_home`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ip_type`
[INFO] [stdout]  --> src/enum_match.rs:4:15
[INFO] [stdout]   |
[INFO] [stdout] 4 |     fn route (ip_type: IpAddKind) { }
[INFO] [stdout]   |               ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_ip_type`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]  --> src/collections.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let v: Vec<i32> = Vec::new();
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `first`
[INFO] [stdout]   --> src/collections.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let first = &v[0];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_first`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `row`
[INFO] [stdout]   --> src/collections.rs:43:9
[INFO] [stdout]    |
[INFO] [stdout] 43 |     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: `s`
[INFO] [stdout]   --> src/collections.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let mut s = String::new(); // String 这样拥有所有权，被移动就回不来了
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/collections.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |     let s = data.to_string(); // String
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/collections.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let s = "initial contents".to_string();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/collections.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let s = String::from("initial contents");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/collections.rs:62:9
[INFO] [stdout]    |
[INFO] [stdout] 62 |     let s = s1 + "-" + &s2; // String 和 &str。s1 被移动了，不能继续使用
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/collections.rs:72:9
[INFO] [stdout]    |
[INFO] [stdout] 72 |     let hello = &s[0..5];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `world`
[INFO] [stdout]   --> src/collections.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let world = &s[6..11];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_world`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/collections.rs:76:9
[INFO] [stdout]    |
[INFO] [stdout] 76 |     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: `word`
[INFO] [stdout]   --> src/collections.rs:96:9
[INFO] [stdout]    |
[INFO] [stdout] 96 |     let word = first_word(&s); // word 的值为 5
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `scores`
[INFO] [stdout]    --> src/collections.rs:125:9
[INFO] [stdout]     |
[INFO] [stdout] 125 |     let scores: HashMap<_, _> = teams.iter().zip(initial_scores.iter()).collect();
[INFO] [stdout]     |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_scores`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer`
[INFO] [stdout]   --> src/generics_trait.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let integer = Point{ x: 5, y: 10 };
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]    --> src/generics_trait.rs:107:43
[INFO] [stdout]     |
[INFO] [stdout] 107 |     pub fn notify2<T: School> (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: `t`
[INFO] [stdout]    --> src/generics_trait.rs:115:28
[INFO] [stdout]     |
[INFO] [stdout] 115 |     fn some_function<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]    --> src/generics_trait.rs:115:34
[INFO] [stdout]     |
[INFO] [stdout] 115 |     fn some_function<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: unused variable: `string2`
[INFO] [stdout]    --> src/generics_trait.rs:241:13
[INFO] [stdout]     |
[INFO] [stdout] 241 |         let string2 = String::from("xyz");
[INFO] [stdout]     |             ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_string2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/generics_trait.rs:248:33
[INFO] [stdout]     |
[INFO] [stdout] 248 |     fn longest2<'a>(x: &'a str, y: &str) -> &'a str {
[INFO] [stdout]     |                                 ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/collections.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let mut s = String::new(); // String 这样拥有所有权，被移动就回不来了
[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: unused variable: `y`
[INFO] [stdout]   --> src/common.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let y = {
[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: unused variable: `number`
[INFO] [stdout]   --> src/common.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let number = if condition {
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user1`
[INFO] [stdout]  --> src/structs.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let user1 = User{
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user2`
[INFO] [stdout]   --> src/structs.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let user2 = User{
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `four`
[INFO] [stdout]  --> src/enum_match.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let four = IpAddKind::V4;
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_four`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `home`
[INFO] [stdout]   --> src/enum_match.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let home = IpAddr{ kind: IpAddKind::V4, address: String::from("127.0.0.1") };
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_home`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ip_type`
[INFO] [stdout]  --> src/enum_match.rs:4:15
[INFO] [stdout]   |
[INFO] [stdout] 4 |     fn route (ip_type: IpAddKind) { }
[INFO] [stdout]   |               ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_ip_type`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]  --> src/collections.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let v: Vec<i32> = Vec::new();
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `first`
[INFO] [stdout]   --> src/collections.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let first = &v[0];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_first`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `row`
[INFO] [stdout]   --> src/collections.rs:43:9
[INFO] [stdout]    |
[INFO] [stdout] 43 |     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: `s`
[INFO] [stdout]   --> src/collections.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let mut s = String::new(); // String 这样拥有所有权，被移动就回不来了
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/collections.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |     let s = data.to_string(); // String
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/collections.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let s = "initial contents".to_string();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/collections.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let s = String::from("initial contents");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/collections.rs:62:9
[INFO] [stdout]    |
[INFO] [stdout] 62 |     let s = s1 + "-" + &s2; // String 和 &str。s1 被移动了，不能继续使用
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/collections.rs:72:9
[INFO] [stdout]    |
[INFO] [stdout] 72 |     let hello = &s[0..5];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `world`
[INFO] [stdout]   --> src/collections.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let world = &s[6..11];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_world`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/collections.rs:76:9
[INFO] [stdout]    |
[INFO] [stdout] 76 |     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: `word`
[INFO] [stdout]   --> src/collections.rs:96:9
[INFO] [stdout]    |
[INFO] [stdout] 96 |     let word = first_word(&s); // word 的值为 5
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `scores`
[INFO] [stdout]    --> src/collections.rs:125:9
[INFO] [stdout]     |
[INFO] [stdout] 125 |     let scores: HashMap<_, _> = teams.iter().zip(initial_scores.iter()).collect();
[INFO] [stdout]     |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_scores`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer`
[INFO] [stdout]   --> src/generics_trait.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let integer = Point{ x: 5, y: 10 };
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]    --> src/generics_trait.rs:107:43
[INFO] [stdout]     |
[INFO] [stdout] 107 |     pub fn notify2<T: School> (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: `t`
[INFO] [stdout]    --> src/generics_trait.rs:115:28
[INFO] [stdout]     |
[INFO] [stdout] 115 |     fn some_function<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]    --> src/generics_trait.rs:115:34
[INFO] [stdout]     |
[INFO] [stdout] 115 |     fn some_function<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: unused variable: `string2`
[INFO] [stdout]    --> src/generics_trait.rs:241:13
[INFO] [stdout]     |
[INFO] [stdout] 241 |         let string2 = String::from("xyz");
[INFO] [stdout]     |             ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_string2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/generics_trait.rs:248:33
[INFO] [stdout]     |
[INFO] [stdout] 248 |     fn longest2<'a>(x: &'a str, y: &str) -> &'a str {
[INFO] [stdout]     |                                 ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/error.rs:90:13
[INFO] [stdout]    |
[INFO] [stdout] 90 |         let mut guess = String::new();
[INFO] [stdout]    |             ----^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/error.rs:48:13
[INFO] [stdout]    |
[INFO] [stdout] 48 |         let mut f = File::open("fuck.txt");
[INFO] [stdout]    |             ----^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `active`
[INFO] [stdout]  --> src/structs.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |         active: bool,
[INFO] [stdout]   |         ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `build_user`
[INFO] [stdout]   --> src/structs.rs:23:8
[INFO] [stdout]    |
[INFO] [stdout] 23 |     fn build_user(username: String) -> User{
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `can_hold`
[INFO] [stdout]   --> src/structs.rs:65:12
[INFO] [stdout]    |
[INFO] [stdout] 65 |         fn can_hold(&self, other: &Rectangle) -> bool{
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `V6`
[INFO] [stdout]  --> src/enum_match.rs:2:24
[INFO] [stdout]   |
[INFO] [stdout] 2 |     enum IpAddKind {V4,V6,}
[INFO] [stdout]   |                        ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `kind`
[INFO] [stdout]  --> src/enum_match.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |         kind: IpAddKind,
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `address`
[INFO] [stdout]  --> src/enum_match.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |         address: String,
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Quit`
[INFO] [stdout]   --> src/enum_match.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |         Quit,   // 没有关联任何数据
[INFO] [stdout]    |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Move`
[INFO] [stdout]   --> src/enum_match.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |         Move {x: i32, y: i32},  // 包含一个匿名结构体
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `ChangeColor`
[INFO] [stdout]   --> src/enum_match.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |         ChangeColor(i32, i32, i32), // 包含三个 i32
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_username_from_file1`
[INFO] [stdout]   --> src/error.rs:69:8
[INFO] [stdout]    |
[INFO] [stdout] 69 |     fn read_username_from_file1() -> Result<String, io::Error> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Guess`
[INFO] [stdout]    --> src/error.rs:104:16
[INFO] [stdout]     |
[INFO] [stdout] 104 |     pub struct Guess {
[INFO] [stdout]     |                ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]    --> src/error.rs:109:16
[INFO] [stdout]     |
[INFO] [stdout] 109 |         pub fn new(value: i32) -> Guess {
[INFO] [stdout]     |                ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `value`
[INFO] [stdout]    --> src/error.rs:117:16
[INFO] [stdout]     |
[INFO] [stdout] 117 |         pub fn value(&self) -> i32 {
[INFO] [stdout]     |                ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `y`
[INFO] [stdout]   --> src/generics_trait.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |         y: T,
[INFO] [stdout]    |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Option`
[INFO] [stdout]   --> src/generics_trait.rs:34:10
[INFO] [stdout]    |
[INFO] [stdout] 34 |     enum Option<T> {
[INFO] [stdout]    |          ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Result`
[INFO] [stdout]   --> src/generics_trait.rs:38:10
[INFO] [stdout]    |
[INFO] [stdout] 38 |     enum Result<T, E> {
[INFO] [stdout]    |          ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Point1`
[INFO] [stdout]   --> src/generics_trait.rs:50:12
[INFO] [stdout]    |
[INFO] [stdout] 50 |     struct Point1<T, U> {
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `mixup`
[INFO] [stdout]   --> src/generics_trait.rs:55:12
[INFO] [stdout]    |
[INFO] [stdout] 55 |         fn mixup<V, W>(self, other: Point1<V, W>) -> Point1<T, W> {
[INFO] [stdout]    |            ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify`
[INFO] [stdout]    --> src/generics_trait.rs:100:12
[INFO] [stdout]     |
[INFO] [stdout] 100 |     pub fn notify(item: impl School){
[INFO] [stdout]     |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify1`
[INFO] [stdout]    --> src/generics_trait.rs:104:12
[INFO] [stdout]     |
[INFO] [stdout] 104 |     pub fn notify1<T: School> (item: &T) {
[INFO] [stdout]     |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify2`
[INFO] [stdout]    --> src/generics_trait.rs:107:12
[INFO] [stdout]     |
[INFO] [stdout] 107 |     pub fn notify2<T: School> (item1: &T, item2: &T) {
[INFO] [stdout]     |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify3`
[INFO] [stdout]    --> src/generics_trait.rs:111:12
[INFO] [stdout]     |
[INFO] [stdout] 111 |     pub fn notify3<T: School + teacher>(item: T) -> String{
[INFO] [stdout]     |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `some_function`
[INFO] [stdout]    --> src/generics_trait.rs:115:8
[INFO] [stdout]     |
[INFO] [stdout] 115 |     fn some_function<T, U>(t: T, u: U) -> i32
[INFO] [stdout]     |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `return_school`
[INFO] [stdout]    --> src/generics_trait.rs:122:8
[INFO] [stdout]     |
[INFO] [stdout] 122 |     fn return_school() -> impl School {
[INFO] [stdout]     |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `longest2`
[INFO] [stdout]    --> src/generics_trait.rs:248:8
[INFO] [stdout]     |
[INFO] [stdout] 248 |     fn longest2<'a>(x: &'a str, y: &str) -> &'a str {
[INFO] [stdout]     |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/collections.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let mut s = String::new(); // String 这样拥有所有权，被移动就回不来了
[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 `String1` should have a snake case name
[INFO] [stdout]   --> src/collections.rs:49:8
[INFO] [stdout]    |
[INFO] [stdout] 49 | pub fn String1() {
[INFO] [stdout]    |        ^^^^^^^ help: convert the identifier to snake case (notice the capitalization): `string1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 57 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/error.rs:90:13
[INFO] [stdout]    |
[INFO] [stdout] 90 |         let mut guess = String::new();
[INFO] [stdout]    |             ----^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/error.rs:48:13
[INFO] [stdout]    |
[INFO] [stdout] 48 |         let mut f = File::open("fuck.txt");
[INFO] [stdout]    |             ----^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `active`
[INFO] [stdout]  --> src/structs.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |         active: bool,
[INFO] [stdout]   |         ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `build_user`
[INFO] [stdout]   --> src/structs.rs:23:8
[INFO] [stdout]    |
[INFO] [stdout] 23 |     fn build_user(username: String) -> User{
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `can_hold`
[INFO] [stdout]   --> src/structs.rs:65:12
[INFO] [stdout]    |
[INFO] [stdout] 65 |         fn can_hold(&self, other: &Rectangle) -> bool{
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `V6`
[INFO] [stdout]  --> src/enum_match.rs:2:24
[INFO] [stdout]   |
[INFO] [stdout] 2 |     enum IpAddKind {V4,V6,}
[INFO] [stdout]   |                        ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `kind`
[INFO] [stdout]  --> src/enum_match.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |         kind: IpAddKind,
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `address`
[INFO] [stdout]  --> src/enum_match.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |         address: String,
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Quit`
[INFO] [stdout]   --> src/enum_match.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |         Quit,   // 没有关联任何数据
[INFO] [stdout]    |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Move`
[INFO] [stdout]   --> src/enum_match.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |         Move {x: i32, y: i32},  // 包含一个匿名结构体
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `ChangeColor`
[INFO] [stdout]   --> src/enum_match.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |         ChangeColor(i32, i32, i32), // 包含三个 i32
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_username_from_file1`
[INFO] [stdout]   --> src/error.rs:69:8
[INFO] [stdout]    |
[INFO] [stdout] 69 |     fn read_username_from_file1() -> Result<String, io::Error> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Guess`
[INFO] [stdout]    --> src/error.rs:104:16
[INFO] [stdout]     |
[INFO] [stdout] 104 |     pub struct Guess {
[INFO] [stdout]     |                ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]    --> src/error.rs:109:16
[INFO] [stdout]     |
[INFO] [stdout] 109 |         pub fn new(value: i32) -> Guess {
[INFO] [stdout]     |                ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `value`
[INFO] [stdout]    --> src/error.rs:117:16
[INFO] [stdout]     |
[INFO] [stdout] 117 |         pub fn value(&self) -> i32 {
[INFO] [stdout]     |                ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `y`
[INFO] [stdout]   --> src/generics_trait.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |         y: T,
[INFO] [stdout]    |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Option`
[INFO] [stdout]   --> src/generics_trait.rs:34:10
[INFO] [stdout]    |
[INFO] [stdout] 34 |     enum Option<T> {
[INFO] [stdout]    |          ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Result`
[INFO] [stdout]   --> src/generics_trait.rs:38:10
[INFO] [stdout]    |
[INFO] [stdout] 38 |     enum Result<T, E> {
[INFO] [stdout]    |          ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Point1`
[INFO] [stdout]   --> src/generics_trait.rs:50:12
[INFO] [stdout]    |
[INFO] [stdout] 50 |     struct Point1<T, U> {
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `mixup`
[INFO] [stdout]   --> src/generics_trait.rs:55:12
[INFO] [stdout]    |
[INFO] [stdout] 55 |         fn mixup<V, W>(self, other: Point1<V, W>) -> Point1<T, W> {
[INFO] [stdout]    |            ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify`
[INFO] [stdout]    --> src/generics_trait.rs:100:12
[INFO] [stdout]     |
[INFO] [stdout] 100 |     pub fn notify(item: impl School){
[INFO] [stdout]     |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify1`
[INFO] [stdout]    --> src/generics_trait.rs:104:12
[INFO] [stdout]     |
[INFO] [stdout] 104 |     pub fn notify1<T: School> (item: &T) {
[INFO] [stdout]     |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify2`
[INFO] [stdout]    --> src/generics_trait.rs:107:12
[INFO] [stdout]     |
[INFO] [stdout] 107 |     pub fn notify2<T: School> (item1: &T, item2: &T) {
[INFO] [stdout]     |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify3`
[INFO] [stdout]    --> src/generics_trait.rs:111:12
[INFO] [stdout]     |
[INFO] [stdout] 111 |     pub fn notify3<T: School + teacher>(item: T) -> String{
[INFO] [stdout]     |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `some_function`
[INFO] [stdout]    --> src/generics_trait.rs:115:8
[INFO] [stdout]     |
[INFO] [stdout] 115 |     fn some_function<T, U>(t: T, u: U) -> i32
[INFO] [stdout]     |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `return_school`
[INFO] [stdout]    --> src/generics_trait.rs:122:8
[INFO] [stdout]     |
[INFO] [stdout] 122 |     fn return_school() -> impl School {
[INFO] [stdout]     |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `longest2`
[INFO] [stdout]    --> src/generics_trait.rs:248:8
[INFO] [stdout]     |
[INFO] [stdout] 248 |     fn longest2<'a>(x: &'a str, y: &str) -> &'a str {
[INFO] [stdout]     |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `String1` should have a snake case name
[INFO] [stdout]   --> src/collections.rs:49:8
[INFO] [stdout]    |
[INFO] [stdout] 49 | pub fn String1() {
[INFO] [stdout]    |        ^^^^^^^ help: convert the identifier to snake case (notice the capitalization): `string1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 57 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `rust_study::error::e2`
[INFO] [stdout]  --> src/main.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use rust_study::error::e2;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `generics`, `traits`
[INFO] [stdout]  --> src/main.rs:4:34
[INFO] [stdout]   |
[INFO] [stdout] 4 | use rust_study::generics_trait::{generics, traits, lifetime};
[INFO] [stdout]   |                                  ^^^^^^^^  ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `rust_study::error::e2`
[INFO] [stdout]  --> src/main.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use rust_study::error::e2;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `generics`, `traits`
[INFO] [stdout]  --> src/main.rs:4:34
[INFO] [stdout]   |
[INFO] [stdout] 4 | use rust_study::generics_trait::{generics, traits, lifetime};
[INFO] [stdout]   |                                  ^^^^^^^^  ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.21s
[INFO] running `Command { std: "docker" "inspect" "d549f70ae038df6c076f92955c9f482aa4f0683d4d06c103363dc7373d3f95b4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d549f70ae038df6c076f92955c9f482aa4f0683d4d06c103363dc7373d3f95b4", kill_on_drop: false }`
[INFO] [stdout] d549f70ae038df6c076f92955c9f482aa4f0683d4d06c103363dc7373d3f95b4