[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] dcd81ff27c0108cad15d475338dbf701848b27f2
[INFO] checking lazylook2/rust_study against master#b2728d5426bab1d8c39709768c7e22b7f66dde5d for pr-135852
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flazylook2%2Frust_study" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/lazylook2/rust_study on toolchain b2728d5426bab1d8c39709768c7e22b7f66dde5d
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b2728d5426bab1d8c39709768c7e22b7f66dde5d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", 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-6-tc1/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: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b2728d5426bab1d8c39709768c7e22b7f66dde5d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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:c80049f3b88b82089a44e0f06d0d6029d44b96b7257e55a1cd63dbc9f4c33334" "/opt/rustwide/cargo-home/bin/cargo" "+b2728d5426bab1d8c39709768c7e22b7f66dde5d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6fb8a97ba4f6a1e3575e1b7ca633b34794cae01f358528e7eae25be0e01677aa
[INFO] running `Command { std: "docker" "start" "-a" "6fb8a97ba4f6a1e3575e1b7ca633b34794cae01f358528e7eae25be0e01677aa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6fb8a97ba4f6a1e3575e1b7ca633b34794cae01f358528e7eae25be0e01677aa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6fb8a97ba4f6a1e3575e1b7ca633b34794cae01f358528e7eae25be0e01677aa", kill_on_drop: false }`
[INFO] [stdout] 6fb8a97ba4f6a1e3575e1b7ca633b34794cae01f358528e7eae25be0e01677aa
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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" "RUSTDOCFLAGS=--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:c80049f3b88b82089a44e0f06d0d6029d44b96b7257e55a1cd63dbc9f4c33334" "/opt/rustwide/cargo-home/bin/cargo" "+b2728d5426bab1d8c39709768c7e22b7f66dde5d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a352f68364a59a6842d4a3d1dc42bb18c5ded568bd83e40144d7d9fcf6ca0532
[INFO] running `Command { std: "docker" "start" "-a" "a352f68364a59a6842d4a3d1dc42bb18c5ded568bd83e40144d7d9fcf6ca0532", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_study v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::rc::Rc`
[INFO] [stdout]  --> src/concurrency.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::rc::Rc;
[INFO] [stdout]   |     ^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `ErrorKind` and `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] 
[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: cannot test inner items
[INFO] [stdout]    --> src/tests.rs:100:5
[INFO] [stdout]     |
[INFO] [stdout] 100 |     #[test]
[INFO] [stdout]     |     ^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unnameable_test_items)]` on by default
[INFO] [stdout]     = note: this warning originates in the attribute macro `test` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused doc comment
[INFO] [stdout]   --> src/iterators_closures.rs:22:5
[INFO] [stdout]    |
[INFO] [stdout] 22 |     /// 完整标注的闭包定义
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 23 |     let add_one_v2 = |x: u32| -> u32 { x + 1 };
[INFO] [stdout]    |     ------------------------------------------- rustdoc does not generate documentation for statements
[INFO] [stdout]    |
[INFO] [stdout]    = help: use `//` for a plain comment
[INFO] [stdout]    = note: `#[warn(unused_doc_comments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused doc comment
[INFO] [stdout]   --> src/iterators_closures.rs:24:5
[INFO] [stdout]    |
[INFO] [stdout] 24 | /     /// 闭包定义中省略了类型注解（现在要编译器需要返回类型了，目前编译不通过）
[INFO] [stdout] 25 | |     // let add_one_v3 = |x| { x + 1 };
[INFO] [stdout] 26 | |     /// 去掉了可选的大括号（现在要编译器需要返回类型了，目前编译不通过）
[INFO] [stdout]    | |________________________________________________________________________^
[INFO] [stdout] ...
[INFO] [stdout] 29 |       let example_closure = |x| x;
[INFO] [stdout]    |       ---------------------------- rustdoc does not generate documentation for statements
[INFO] [stdout]    |
[INFO] [stdout]    = help: use `//` for a plain comment
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]    --> src/advanced_features.rs:243:6
[INFO] [stdout]     |
[INFO] [stdout] 243 |     };
[INFO] [stdout]     |      ^ help: remove this semicolon
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(redundant_semicolons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::error::Error`
[INFO] [stdout]    --> src/advanced_features.rs:308:5
[INFO] [stdout]     |
[INFO] [stdout] 308 | use std::error::Error;
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::rc::Rc`
[INFO] [stdout]  --> src/concurrency.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::rc::Rc;
[INFO] [stdout]   |     ^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `ErrorKind` and `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] 
[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 doc comment
[INFO] [stdout]   --> src/iterators_closures.rs:22:5
[INFO] [stdout]    |
[INFO] [stdout] 22 |     /// 完整标注的闭包定义
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 23 |     let add_one_v2 = |x: u32| -> u32 { x + 1 };
[INFO] [stdout]    |     ------------------------------------------- rustdoc does not generate documentation for statements
[INFO] [stdout]    |
[INFO] [stdout]    = help: use `//` for a plain comment
[INFO] [stdout]    = note: `#[warn(unused_doc_comments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused doc comment
[INFO] [stdout]   --> src/iterators_closures.rs:24:5
[INFO] [stdout]    |
[INFO] [stdout] 24 | /     /// 闭包定义中省略了类型注解（现在要编译器需要返回类型了，目前编译不通过）
[INFO] [stdout] 25 | |     // let add_one_v3 = |x| { x + 1 };
[INFO] [stdout] 26 | |     /// 去掉了可选的大括号（现在要编译器需要返回类型了，目前编译不通过）
[INFO] [stdout]    | |________________________________________________________________________^
[INFO] [stdout] ...
[INFO] [stdout] 29 |       let example_closure = |x| x;
[INFO] [stdout]    |       ---------------------------- rustdoc does not generate documentation for statements
[INFO] [stdout]    |
[INFO] [stdout]    = help: use `//` for a plain comment
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]    --> src/advanced_features.rs:243:6
[INFO] [stdout]     |
[INFO] [stdout] 243 |     };
[INFO] [stdout]     |      ^ help: remove this semicolon
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(redundant_semicolons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::error::Error`
[INFO] [stdout]    --> src/advanced_features.rs:308:5
[INFO] [stdout]     |
[INFO] [stdout] 308 | use std::error::Error;
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^
[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: `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: `s`
[INFO] [stdout]   --> src/collections.rs:57:13
[INFO] [stdout]    |
[INFO] [stdout] 57 |     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:58:9
[INFO] [stdout]    |
[INFO] [stdout] 58 |     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:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |     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:60:9
[INFO] [stdout]    |
[INFO] [stdout] 60 |     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:68:9
[INFO] [stdout]    |
[INFO] [stdout] 68 |     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:78:9
[INFO] [stdout]    |
[INFO] [stdout] 78 |     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:79:9
[INFO] [stdout]    |
[INFO] [stdout] 79 |     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:82:9
[INFO] [stdout]    |
[INFO] [stdout] 82 |     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:102:9
[INFO] [stdout]     |
[INFO] [stdout] 102 |     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: `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: variable does not need to be mutable
[INFO] [stdout]   --> src/collections.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 |     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: `scores`
[INFO] [stdout]    --> src/collections.rs:131:9
[INFO] [stdout]     |
[INFO] [stdout] 131 |     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: 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: 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: `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: `item2`
[INFO] [stdout]    --> src/generics_trait.rs:108:42
[INFO] [stdout]     |
[INFO] [stdout] 108 |     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: `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: `t`
[INFO] [stdout]    --> src/generics_trait.rs:116:28
[INFO] [stdout]     |
[INFO] [stdout] 116 |     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:116:34
[INFO] [stdout]     |
[INFO] [stdout] 116 |     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:243:13
[INFO] [stdout]     |
[INFO] [stdout] 243 |         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: `s`
[INFO] [stdout]    --> src/generics_trait.rs:305:9
[INFO] [stdout]     |
[INFO] [stdout] 305 |     let s: &'static str = "I have a static lifetime.";
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/generics_trait.rs:250:33
[INFO] [stdout]     |
[INFO] [stdout] 250 |     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: unused variable: `s`
[INFO] [stdout]   --> src/collections.rs:57:13
[INFO] [stdout]    |
[INFO] [stdout] 57 |     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: `i`
[INFO] [stdout]    --> src/generics_trait.rs:281:14
[INFO] [stdout]     |
[INFO] [stdout] 281 |         for (i, &item) in bytes.iter().enumerate() {
[INFO] [stdout]     |              ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/collections.rs:58:9
[INFO] [stdout]    |
[INFO] [stdout] 58 |     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:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |     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:60:9
[INFO] [stdout]    |
[INFO] [stdout] 60 |     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:68:9
[INFO] [stdout]    |
[INFO] [stdout] 68 |     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:78:9
[INFO] [stdout]    |
[INFO] [stdout] 78 |     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:79:9
[INFO] [stdout]    |
[INFO] [stdout] 79 |     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:82:9
[INFO] [stdout]    |
[INFO] [stdout] 82 |     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:102:9
[INFO] [stdout]     |
[INFO] [stdout] 102 |     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: `name`
[INFO] [stdout]   --> src/tests.rs:34:17
[INFO] [stdout]    |
[INFO] [stdout] 34 |     fn greeting(name: &str) -> String {
[INFO] [stdout]    |                 ^^^^ help: if this is intentional, prefix it with an underscore: `_name`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `add_one_v2`
[INFO] [stdout]   --> src/iterators_closures.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let add_one_v2 = |x: u32| -> u32 { x + 1 };
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_add_one_v2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/iterators_closures.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let s = example_closure(String::from("hello"));
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/collections.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 |     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: `scores`
[INFO] [stdout]    --> src/collections.rs:131:9
[INFO] [stdout]     |
[INFO] [stdout] 131 |     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: `i`
[INFO] [stdout]   --> src/pointers.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let i = 2;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `j`
[INFO] [stdout]   --> src/pointers.rs:26:31
[INFO] [stdout]    |
[INFO] [stdout] 26 |                 List::Cons(i, j) => {println!("第二层：{}", i);},
[INFO] [stdout]    |                               ^ help: if this is intentional, prefix it with an underscore: `_j`
[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: 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: `c`
[INFO] [stdout]    --> src/pointers.rs:154:9
[INFO] [stdout]     |
[INFO] [stdout] 154 |     let c = Cons(4, Rc::clone(&a));
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]    --> src/pointers.rs:162:9
[INFO] [stdout]     |
[INFO] [stdout] 162 |     let b = Cons(3, Rc::clone(&a));
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]    --> src/pointers.rs:165:13
[INFO] [stdout]     |
[INFO] [stdout] 165 |         let c = Cons(4, Rc::clone(&a));
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]    --> src/pointers.rs:175:9
[INFO] [stdout]     |
[INFO] [stdout] 175 |     let a = AA{ aa: Rc::clone(&x), bb: 0 };
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]    --> src/pointers.rs:176:9
[INFO] [stdout]     |
[INFO] [stdout] 176 |     let b = AA{ aa: Rc::clone(&x), bb: 1 };
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/pointers.rs:174:9
[INFO] [stdout]     |
[INFO] [stdout] 174 |     let mut x = Rc::new(3);
[INFO] [stdout]     |         ----^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]    --> src/generics_trait.rs:108:42
[INFO] [stdout]     |
[INFO] [stdout] 108 |     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:116:28
[INFO] [stdout]     |
[INFO] [stdout] 116 |     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:116:34
[INFO] [stdout]     |
[INFO] [stdout] 116 |     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: `branch`
[INFO] [stdout]    --> src/pointers.rs:294:9
[INFO] [stdout]     |
[INFO] [stdout] 294 |     let branch = Rc::new(
[INFO] [stdout]     |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_branch`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `string2`
[INFO] [stdout]    --> src/generics_trait.rs:243:13
[INFO] [stdout]     |
[INFO] [stdout] 243 |         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: `s`
[INFO] [stdout]    --> src/generics_trait.rs:305:9
[INFO] [stdout]     |
[INFO] [stdout] 305 |     let s: &'static str = "I have a static lifetime.";
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/generics_trait.rs:250:33
[INFO] [stdout]     |
[INFO] [stdout] 250 |     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: unused variable: `i`
[INFO] [stdout]    --> src/generics_trait.rs:281:14
[INFO] [stdout]     |
[INFO] [stdout] 281 |         for (i, &item) in bytes.iter().enumerate() {
[INFO] [stdout]     |              ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `add_one_v2`
[INFO] [stdout]   --> src/iterators_closures.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let add_one_v2 = |x: u32| -> u32 { x + 1 };
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_add_one_v2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/iterators_closures.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let s = example_closure(String::from("hello"));
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `post`
[INFO] [stdout]    --> src/object_oriented.rs:173:31
[INFO] [stdout]     |
[INFO] [stdout] 173 |         fn content<'a>(&self, post: &'a Post) -> &'a str {
[INFO] [stdout]     |                               ^^^^ help: if this is intentional, prefix it with an underscore: `_post`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/patterns.rs:111:19
[INFO] [stdout]     |
[INFO] [stdout] 111 |     let Point{ x, y} = p;
[INFO] [stdout]     |                   ^ help: try ignoring the field: `y: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/patterns.rs:192:9
[INFO] [stdout]     |
[INFO] [stdout] 192 |     let y = 10;
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/pointers.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let i = 2;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/advanced_features.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |     let slice: &[i32] = unsafe {
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `j`
[INFO] [stdout]   --> src/pointers.rs:26:31
[INFO] [stdout]    |
[INFO] [stdout] 26 |                 List::Cons(i, j) => {println!("第二层：{}", i);},
[INFO] [stdout]    |                               ^ help: if this is intentional, prefix it with an underscore: `_j`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]    --> src/pointers.rs:154:9
[INFO] [stdout]     |
[INFO] [stdout] 154 |     let c = Cons(4, Rc::clone(&a));
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]    --> src/pointers.rs:162:9
[INFO] [stdout]     |
[INFO] [stdout] 162 |     let b = Cons(3, Rc::clone(&a));
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]    --> src/pointers.rs:165:13
[INFO] [stdout]     |
[INFO] [stdout] 165 |         let c = Cons(4, Rc::clone(&a));
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]    --> src/pointers.rs:175:9
[INFO] [stdout]     |
[INFO] [stdout] 175 |     let a = AA{ aa: Rc::clone(&x), bb: 0 };
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]    --> src/pointers.rs:176:9
[INFO] [stdout]     |
[INFO] [stdout] 176 |     let b = AA{ aa: Rc::clone(&x), bb: 1 };
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/pointers.rs:174:9
[INFO] [stdout]     |
[INFO] [stdout] 174 |     let mut x = Rc::new(3);
[INFO] [stdout]     |         ----^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `guess`
[INFO] [stdout]    --> src/advanced_features.rs:358:13
[INFO] [stdout]     |
[INFO] [stdout] 358 |         let guess: u32 = match guess.trim().parse() {
[INFO] [stdout]     |             ^^^^^ help: if this is intentional, prefix it with an underscore: `_guess`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `branch`
[INFO] [stdout]    --> src/pointers.rs:294:9
[INFO] [stdout]     |
[INFO] [stdout] 294 |     let branch = Rc::new(
[INFO] [stdout]     |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_branch`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `post`
[INFO] [stdout]    --> src/object_oriented.rs:173:31
[INFO] [stdout]     |
[INFO] [stdout] 173 |         fn content<'a>(&self, post: &'a Post) -> &'a str {
[INFO] [stdout]     |                               ^^^^ help: if this is intentional, prefix it with an underscore: `_post`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `active` is never read
[INFO] [stdout]  --> src/structs.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     struct User {
[INFO] [stdout]   |            ---- field in this struct
[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 `build_user` is never used
[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: fields `0` and `1` are never read
[INFO] [stdout]   --> src/structs.rs:45:18
[INFO] [stdout]    |
[INFO] [stdout] 45 |     struct Color(i32, i32, i32);
[INFO] [stdout]    |            ----- ^^^  ^^^
[INFO] [stdout]    |            |
[INFO] [stdout]    |            fields in this struct
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]    |
[INFO] [stdout] 45 |     struct Color((), (), i32);
[INFO] [stdout]    |                  ~~  ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `can_hold` is never used
[INFO] [stdout]   --> src/structs.rs:65:12
[INFO] [stdout]    |
[INFO] [stdout] 61 |     impl Rectangle {
[INFO] [stdout]    |     -------------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 65 |         fn can_hold(&self, other: &Rectangle) -> bool{
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `V6` is never constructed
[INFO] [stdout]  --> src/enum_match.rs:2:24
[INFO] [stdout]   |
[INFO] [stdout] 2 |     enum IpAddKind {V4,V6,}
[INFO] [stdout]   |          ---------     ^^
[INFO] [stdout]   |          |
[INFO] [stdout]   |          variant in this enum
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `kind` and `address` are never read
[INFO] [stdout]  --> src/enum_match.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     struct IpAddr {
[INFO] [stdout]   |            ------ fields in this struct
[INFO] [stdout] 7 |         kind: IpAddKind,
[INFO] [stdout]   |         ^^^^
[INFO] [stdout] 8 |         address: String,
[INFO] [stdout]   |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Quit`, `Move`, and `ChangeColor` are never constructed
[INFO] [stdout]   --> src/enum_match.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     enum Message {
[INFO] [stdout]    |          ------- variants in this enum
[INFO] [stdout] 13 |         Quit,   // 没有关联任何数据
[INFO] [stdout]    |         ^^^^
[INFO] [stdout] 14 |         Move {x: i32, y: i32},  // 包含一个匿名结构体
[INFO] [stdout]    |         ^^^^
[INFO] [stdout] 15 |         Write(String),  // 包含单独一个 String
[INFO] [stdout] 16 |         ChangeColor(i32, i32, i32), // 包含三个 i32
[INFO] [stdout]    |         ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/collections.rs:34:13
[INFO] [stdout]    |
[INFO] [stdout] 34 |         Int(i32),
[INFO] [stdout]    |         --- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 34 |         Int(()),
[INFO] [stdout]    |             ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/collections.rs:35:15
[INFO] [stdout]    |
[INFO] [stdout] 35 |         Float(f64),
[INFO] [stdout]    |         ----- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 35 |         Float(()),
[INFO] [stdout]    |               ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/collections.rs:36:14
[INFO] [stdout]    |
[INFO] [stdout] 36 |         Text(String),
[INFO] [stdout]    |         ---- ^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 36 |         Text(()),
[INFO] [stdout]    |              ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `parse_config` is never used
[INFO] [stdout]   --> src/collections.rs:49:8
[INFO] [stdout]    |
[INFO] [stdout] 49 |     fn parse_config(args: &[String]) -> (&str, &str) {
[INFO] [stdout]    |        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `read_username_from_file1` is never used
[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 `Guess` is never constructed
[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 items `new` and `value` are never used
[INFO] [stdout]    --> src/error.rs:109:16
[INFO] [stdout]     |
[INFO] [stdout] 108 |     impl Guess {
[INFO] [stdout]     |     ---------- associated items in this implementation
[INFO] [stdout] 109 |         pub fn new(value: i32) -> Guess {
[INFO] [stdout]     |                ^^^
[INFO] [stdout] ...
[INFO] [stdout] 117 |         pub fn value(&self) -> i32 {
[INFO] [stdout]     |                ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `y` is never read
[INFO] [stdout]   --> src/generics_trait.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     struct Point<T> {
[INFO] [stdout]    |            ----- field in this struct
[INFO] [stdout] 29 |         x: T,
[INFO] [stdout] 30 |         y: T,
[INFO] [stdout]    |         ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Option` is never used
[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 `Result` is never used
[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 `Point1` is never constructed
[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: method `mixup` is never used
[INFO] [stdout]   --> src/generics_trait.rs:55:12
[INFO] [stdout]    |
[INFO] [stdout] 54 |     impl<T, U> Point1<T, U> {
[INFO] [stdout]    |     ----------------------- method in this implementation
[INFO] [stdout] 55 |         fn mixup<V, W>(self, other: Point1<V, W>) -> Point1<T, W> {
[INFO] [stdout]    |            ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `teacher` is never used
[INFO] [stdout]   --> src/generics_trait.rs:73:15
[INFO] [stdout]    |
[INFO] [stdout] 73 |     pub trait teacher {
[INFO] [stdout]    |               ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify` is never used
[INFO] [stdout]    --> src/generics_trait.rs:101:12
[INFO] [stdout]     |
[INFO] [stdout] 101 |     pub fn notify(item: impl School) {
[INFO] [stdout]     |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify1` is never used
[INFO] [stdout]    --> src/generics_trait.rs:105:12
[INFO] [stdout]     |
[INFO] [stdout] 105 |     pub fn notify1<T: School>(item: &T) {
[INFO] [stdout]     |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify2` is never used
[INFO] [stdout]    --> src/generics_trait.rs:108:12
[INFO] [stdout]     |
[INFO] [stdout] 108 |     pub fn notify2<T: School>(item1: &T, item2: &T) {
[INFO] [stdout]     |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify3` is never used
[INFO] [stdout]    --> src/generics_trait.rs:112:12
[INFO] [stdout]     |
[INFO] [stdout] 112 |     pub fn notify3<T: School + teacher>(item: T) -> String {
[INFO] [stdout]     |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_function` is never used
[INFO] [stdout]    --> src/generics_trait.rs:116:8
[INFO] [stdout]     |
[INFO] [stdout] 116 |     fn some_function<T, U>(t: T, u: U) -> i32
[INFO] [stdout]     |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `return_school` is never used
[INFO] [stdout]    --> src/generics_trait.rs:123:8
[INFO] [stdout]     |
[INFO] [stdout] 123 |     fn return_school() -> impl School {
[INFO] [stdout]     |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `longest2` is never used
[INFO] [stdout]    --> src/generics_trait.rs:250:8
[INFO] [stdout]     |
[INFO] [stdout] 250 |     fn longest2<'a>(x: &'a str, y: &str) -> &'a str {
[INFO] [stdout]     |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_word` is never used
[INFO] [stdout]    --> src/generics_trait.rs:278:8
[INFO] [stdout]     |
[INFO] [stdout] 278 |     fn first_word(s: &str) -> &str {
[INFO] [stdout]     |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `announce_and_return_part` is never used
[INFO] [stdout]    --> src/generics_trait.rs:298:12
[INFO] [stdout]     |
[INFO] [stdout] 295 |     impl<'a> ImportantExcerpt<'a> {
[INFO] [stdout]     |     ----------------------------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 298 |         fn announce_and_return_part(&self, announcement: &str) -> &str {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `longest_with_an_announcement` is never used
[INFO] [stdout]    --> src/generics_trait.rs:308:8
[INFO] [stdout]     |
[INFO] [stdout] 308 |     fn longest_with_an_announcement<'a, T>(x: &'a str, y: &'a str, ann: T) -> &'a str
[INFO] [stdout]     |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `expensive_test` is never used
[INFO] [stdout]    --> src/tests.rs:102:8
[INFO] [stdout]     |
[INFO] [stdout] 102 |     fn expensive_test() {
[INFO] [stdout]     |        ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `value` is never read
[INFO] [stdout]   --> src/tests.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 48 |     pub struct Guess {
[INFO] [stdout]    |                ----- field in this struct
[INFO] [stdout] 49 |         value: i32,
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `calculate` is never used
[INFO] [stdout]  --> src/iterators_closures.rs:6:8
[INFO] [stdout]   |
[INFO] [stdout] 6 |     fn calculate(a: u32) -> u32 {
[INFO] [stdout]   |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `add_one_v1` is never used
[INFO] [stdout]   --> src/iterators_closures.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     fn  add_one_v1   (x: u32) -> u32 { x + 1 }
[INFO] [stdout]    |         ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Cacher` is never constructed
[INFO] [stdout]   --> src/iterators_closures.rs:36:12
[INFO] [stdout]    |
[INFO] [stdout] 36 |     struct Cacher<T>
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new` and `value` are never used
[INFO] [stdout]   --> src/iterators_closures.rs:44:12
[INFO] [stdout]    |
[INFO] [stdout] 42 |     impl<T> Cacher<T> where T: Fn(u32) -> u32
[INFO] [stdout]    |     ----------------------------------------- associated items in this implementation
[INFO] [stdout] 43 |     {
[INFO] [stdout] 44 |         fn new (calculation: T) -> Cacher<T>{
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 47 |         fn value (&mut self, arg: u32) -> u32 {
[INFO] [stdout]    |            ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]    --> src/pointers.rs:146:14
[INFO] [stdout]     |
[INFO] [stdout] 146 |         Cons(i32, Rc<List>),
[INFO] [stdout]     |         ---- ^^^  ^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         fields in this variant
[INFO] [stdout]     |
[INFO] [stdout]     = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]     |
[INFO] [stdout] 146 |         Cons((), ()),
[INFO] [stdout]     |              ~~  ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `aa` and `bb` are never read
[INFO] [stdout]    --> src/pointers.rs:173:17
[INFO] [stdout]     |
[INFO] [stdout] 173 |     struct AA { aa: Rc<i32>, bb: i32 }
[INFO] [stdout]     |            --   ^^           ^^
[INFO] [stdout]     |            |
[INFO] [stdout]     |            fields in this struct
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]    --> src/pointers.rs:253:14
[INFO] [stdout]     |
[INFO] [stdout] 253 |         Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stdout]     |         ---- ^^^^^^^^^^^^^^^^  ^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         fields in this variant
[INFO] [stdout]     |
[INFO] [stdout]     = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]     |
[INFO] [stdout] 253 |         Cons((), ()),
[INFO] [stdout]     |              ~~  ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `List` is never used
[INFO] [stdout]    --> src/pointers.rs:272:10
[INFO] [stdout]     |
[INFO] [stdout] 272 |     enum List {
[INFO] [stdout]     |          ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `tail` is never used
[INFO] [stdout]    --> src/pointers.rs:278:12
[INFO] [stdout]     |
[INFO] [stdout] 277 |     impl List {
[INFO] [stdout]     |     --------- method in this implementation
[INFO] [stdout] 278 |         fn tail(&self) -> Option<&RefCell<Rc<List>>> {
[INFO] [stdout]     |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `value` and `children` are never read
[INFO] [stdout]    --> src/pointers.rs:288:9
[INFO] [stdout]     |
[INFO] [stdout] 287 |     struct Node {
[INFO] [stdout]     |            ---- fields in this struct
[INFO] [stdout] 288 |         value: i32,
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout] 289 |         children: RefCell<Vec<Rc<Node>>>,
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `Node` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `width`, `height`, and `label` are never read
[INFO] [stdout]   --> src/object_oriented.rs:76:13
[INFO] [stdout]    |
[INFO] [stdout] 75 |     pub struct Button {
[INFO] [stdout]    |                ------ fields in this struct
[INFO] [stdout] 76 |         pub width: u32,
[INFO] [stdout]    |             ^^^^^
[INFO] [stdout] 77 |         pub height: u32,
[INFO] [stdout]    |             ^^^^^^
[INFO] [stdout] 78 |         pub label: String
[INFO] [stdout]    |             ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `width`, `height`, and `options` are never read
[INFO] [stdout]   --> src/object_oriented.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 85 |     struct SelectBox {
[INFO] [stdout]    |            --------- fields in this struct
[INFO] [stdout] 86 |         width: u32,
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout] 87 |         height: u32,
[INFO] [stdout]    |         ^^^^^^
[INFO] [stdout] 88 |         options: Vec<String>,
[INFO] [stdout]    |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Post` is never constructed
[INFO] [stdout]    --> src/object_oriented.rs:134:16
[INFO] [stdout]     |
[INFO] [stdout] 134 |     pub struct Post {
[INFO] [stdout]     |                ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `add_text`, `content`, `request_review`, and `approve` are never used
[INFO] [stdout]    --> src/object_oriented.rs:139:16
[INFO] [stdout]     |
[INFO] [stdout] 138 |     impl Post {
[INFO] [stdout]     |     --------- associated items in this implementation
[INFO] [stdout] 139 |         pub fn new () -> Post{
[INFO] [stdout]     |                ^^^
[INFO] [stdout] ...
[INFO] [stdout] 143 |         pub fn add_text(&mut self, text: &str) {
[INFO] [stdout]     |                ^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 152 |         pub fn content(&self) -> &str{
[INFO] [stdout]     |                ^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 155 |         pub fn request_review(&mut self){
[INFO] [stdout]     |                ^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 162 |         pub fn approve(&mut self){
[INFO] [stdout]     |                ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `State` is never used
[INFO] [stdout]    --> src/object_oriented.rs:170:11
[INFO] [stdout]     |
[INFO] [stdout] 170 |     trait State {
[INFO] [stdout]     |           ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Draft` is never constructed
[INFO] [stdout]    --> src/object_oriented.rs:178:13
[INFO] [stdout]     |
[INFO] [stdout] 178 |     struct  Draft {}
[INFO] [stdout]     |             ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `PendingReview` is never constructed
[INFO] [stdout]    --> src/object_oriented.rs:188:12
[INFO] [stdout]     |
[INFO] [stdout] 188 |     struct PendingReview {}
[INFO] [stdout]     |            ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Published` is never constructed
[INFO] [stdout]    --> src/object_oriented.rs:198:12
[INFO] [stdout]     |
[INFO] [stdout] 198 |     struct Published {}
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Quit`, `Move`, and `Write` are never constructed
[INFO] [stdout]    --> src/patterns.rs:126:9
[INFO] [stdout]     |
[INFO] [stdout] 125 |     enum Message {
[INFO] [stdout]     |          ------- variants in this enum
[INFO] [stdout] 126 |         Quit,
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] 127 |         Move { x: i32, y: i32},
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] 128 |         Write (String),
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `Rgb` is never constructed
[INFO] [stdout]    --> src/patterns.rs:140:9
[INFO] [stdout]     |
[INFO] [stdout] 139 |     enum Color {
[INFO] [stdout]     |          ----- variant in this enum
[INFO] [stdout] 140 |         Rgb(i32, i32, i32),
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Quit`, `Move`, and `Write` are never constructed
[INFO] [stdout]    --> src/patterns.rs:144:9
[INFO] [stdout]     |
[INFO] [stdout] 143 |     enum Message1 {
[INFO] [stdout]     |          -------- variants in this enum
[INFO] [stdout] 144 |         Quit,
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] 145 |         Move { x: i32, y: i32 },
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] 146 |         Write(String),
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `split_at_mut1` is never used
[INFO] [stdout]   --> src/advanced_features.rs:30:12
[INFO] [stdout]    |
[INFO] [stdout] 30 |     pub fn split_at_mut1(slice: &mut [i32], mid: usize) -> (&mut [i32], &mut [i32]) {
[INFO] [stdout]    |            ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `unsafe_rust6` is never used
[INFO] [stdout]   --> src/advanced_features.rs:86:4
[INFO] [stdout]    |
[INFO] [stdout] 86 | fn unsafe_rust6() {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Wizard` is never used
[INFO] [stdout]    --> src/advanced_features.rs:208:11
[INFO] [stdout]     |
[INFO] [stdout] 208 |     trait Wizard {
[INFO] [stdout]     |           ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `name` is never read
[INFO] [stdout]    --> src/advanced_features.rs:242:9
[INFO] [stdout]     |
[INFO] [stdout] 241 |     struct Dog {
[INFO] [stdout]     |            --- field in this struct
[INFO] [stdout] 242 |         name: String
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `OutlinePrint` is never used
[INFO] [stdout]    --> src/advanced_features.rs:268:11
[INFO] [stdout]     |
[INFO] [stdout] 268 |     trait OutlinePrint: fmt::Display {
[INFO] [stdout]     |           ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `Result` is never used
[INFO] [stdout]    --> src/advanced_features.rs:338:10
[INFO] [stdout]     |
[INFO] [stdout] 338 |     type Result<T> = std::result::Result<T, std::io::Error>;
[INFO] [stdout]     |          ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Write` is never used
[INFO] [stdout]    --> src/advanced_features.rs:339:15
[INFO] [stdout]     |
[INFO] [stdout] 339 |     pub trait Write {
[INFO] [stdout]     |               ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `Stop` is never constructed
[INFO] [stdout]    --> src/advanced_features.rs:453:9
[INFO] [stdout]     |
[INFO] [stdout] 451 |     enum Status {
[INFO] [stdout]     |          ------ variant in this enum
[INFO] [stdout] 452 |         Value(u32),
[INFO] [stdout] 453 |         Stop,
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `returns_closure` is never used
[INFO] [stdout]    --> src/advanced_features.rs:481:8
[INFO] [stdout]     |
[INFO] [stdout] 481 |     fn returns_closure() -> Box<dyn Fn(i32) -> i32> {
[INFO] [stdout]     |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `String1` should have a snake case name
[INFO] [stdout]   --> src/collections.rs:55:8
[INFO] [stdout]    |
[INFO] [stdout] 55 | 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: function `Closures` should have a snake case name
[INFO] [stdout]  --> src/iterators_closures.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn Closures() {
[INFO] [stdout]   |        ^^^^^^^^ help: convert the identifier to snake case (notice the capitalization): `closures`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `Iterator` should have a snake case name
[INFO] [stdout]    --> src/iterators_closures.rs:102:8
[INFO] [stdout]     |
[INFO] [stdout] 102 | pub fn Iterator() {
[INFO] [stdout]     |        ^^^^^^^^ help: convert the identifier to snake case (notice the capitalization): `iterator`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `Rc` should have a snake case name
[INFO] [stdout]    --> src/pointers.rs:143:8
[INFO] [stdout]     |
[INFO] [stdout] 143 | pub fn Rc () {
[INFO] [stdout]     |        ^^ help: convert the identifier to snake case: `rc`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: creating a shared reference to mutable static is discouraged
[INFO] [stdout]   --> src/advanced_features.rs:82:33
[INFO] [stdout]    |
[INFO] [stdout] 82 |         println!("COUNTER: {}", COUNTER);
[INFO] [stdout]    |                                 ^^^^^^^ shared reference to mutable static
[INFO] [stdout]    |
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/static-mut-references.html>
[INFO] [stdout]    = note: shared references to mutable statics are dangerous; it's undefined behavior if the static is mutated or if a mutable reference is created for it while the shared reference lives
[INFO] [stdout]    = note: `#[warn(static_mut_refs)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/patterns.rs:111:19
[INFO] [stdout]     |
[INFO] [stdout] 111 |     let Point{ x, y} = p;
[INFO] [stdout]     |                   ^ help: try ignoring the field: `y: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/patterns.rs:192:9
[INFO] [stdout]     |
[INFO] [stdout] 192 |     let y = 10;
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: non-local `macro_rules!` definition, `#[macro_export]` macro should be written at top level module
[INFO] [stdout]    --> src/advanced_features.rs:491:5
[INFO] [stdout]     |
[INFO] [stdout] 491 | /     macro_rules! my_vec {
[INFO] [stdout] 492 | |         ( $( $x: expr ), * ) => {
[INFO] [stdout] 493 | |             {
[INFO] [stdout] 494 | |                 let mut temp_vec = Vec::new();
[INFO] [stdout] ...   |
[INFO] [stdout] 501 | |     }
[INFO] [stdout]     | |_____^
[INFO] [stdout]     |
[INFO] [stdout]     = help: remove the `#[macro_export]` or move this `macro_rules!` outside the of the current function `macros1`
[INFO] [stdout]     = note: a `macro_rules!` definition is non-local if it is nested inside an item and has a `#[macro_export]` attribute
[INFO] [stdout]     = note: `#[warn(non_local_definitions)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/advanced_features.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |     let slice: &[i32] = unsafe {
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `guess`
[INFO] [stdout]    --> src/advanced_features.rs:358:13
[INFO] [stdout]     |
[INFO] [stdout] 358 |         let guess: u32 = match guess.trim().parse() {
[INFO] [stdout]     |             ^^^^^ help: if this is intentional, prefix it with an underscore: `_guess`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `active` is never read
[INFO] [stdout]  --> src/structs.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     struct User {
[INFO] [stdout]   |            ---- field in this struct
[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 `build_user` is never used
[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: fields `0` and `1` are never read
[INFO] [stdout]   --> src/structs.rs:45:18
[INFO] [stdout]    |
[INFO] [stdout] 45 |     struct Color(i32, i32, i32);
[INFO] [stdout]    |            ----- ^^^  ^^^
[INFO] [stdout]    |            |
[INFO] [stdout]    |            fields in this struct
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]    |
[INFO] [stdout] 45 |     struct Color((), (), i32);
[INFO] [stdout]    |                  ~~  ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not parse/generate dep info at: /opt/rustwide/target/debug/deps/rust_study-b83577688c099ec5.d
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   failed to write `/opt/rustwide/target/debug/.fingerprint/rust_study-b83577688c099ec5/dep-test-lib-rust_study`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   No space left on device (os error 28)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `rust_study` (lib); 57 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   No space left on device (os error 28)
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   failed to parse process output: `/opt/rustwide/rustup-home/toolchains/b2728d5426bab1d8c39709768c7e22b7f66dde5d/bin/rustc --crate-name rust_study --edition=2018 src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type lib --emit=dep-info,metadata -C embed-bitcode=no -C debuginfo=2 --check-cfg 'cfg(docsrs,test)' --check-cfg 'cfg(feature, values())' -C metadata=ce0142515cd84ec6 -C extra-filename=-d67f6159a89d3299 --out-dir /opt/rustwide/target/debug/deps -L dependency=/opt/rustwide/target/debug/deps --cap-lints=forbid` (exit status: 0)
[INFO] running `Command { std: "docker" "inspect" "a352f68364a59a6842d4a3d1dc42bb18c5ded568bd83e40144d7d9fcf6ca0532", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a352f68364a59a6842d4a3d1dc42bb18c5ded568bd83e40144d7d9fcf6ca0532", kill_on_drop: false }`
[INFO] [stdout] a352f68364a59a6842d4a3d1dc42bb18c5ded568bd83e40144d7d9fcf6ca0532