[INFO] cloning repository https://github.com/llorz-o/rust-learn
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/llorz-o/rust-learn" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fllorz-o%2Frust-learn", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fllorz-o%2Frust-learn'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 1aa1054ecb956f1c75a8ea58a9a24d7dfc62b13a
[INFO] checking llorz-o/rust-learn against beta for pr-78714
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fllorz-o%2Frust-learn" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/llorz-o/rust-learn on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/llorz-o/rust-learn
[INFO] finished tweaking git repo https://github.com/llorz-o/rust-learn
[INFO] tweaked toml for git repo https://github.com/llorz-o/rust-learn written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/llorz-o/rust-learn already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] bb875fdc918d2ce6965dd5086f098f6b244f655998d220bd3920044a658f8a7c
[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" "bb875fdc918d2ce6965dd5086f098f6b244f655998d220bd3920044a658f8a7c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "bb875fdc918d2ce6965dd5086f098f6b244f655998d220bd3920044a658f8a7c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bb875fdc918d2ce6965dd5086f098f6b244f655998d220bd3920044a658f8a7c", kill_on_drop: false }`
[INFO] [stdout] bb875fdc918d2ce6965dd5086f098f6b244f655998d220bd3920044a658f8a7c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1dacb88a7142a6a26dfabb075a0c9f5ba1fed8780ac57e24041df3c6c8fffe8e
[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" "1dacb88a7142a6a26dfabb075a0c9f5ba1fed8780ac57e24041df3c6c8fffe8e", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.77
[INFO] [stderr]     Checking getrandom v0.1.15
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking rust-learn v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0432]: unresolved import `add_two`
[INFO] [stdout]  --> tests/mode12_test.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use add_two;
[INFO] [stdout]   |     ^^^^^^^ no external crate `add_two`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::copy`
[INFO] [stdout]  --> src/demo/demo1.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::io::copy; // 也可已引入方法
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::*`
[INFO] [stdout]  --> src/demo/demo1.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::collections::*; // 引入模块下所有公共项
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]   --> src/demo/demo3_branches.rs:28:17
[INFO] [stdout]    |
[INFO] [stdout] 28 |     for elem in (1..9) {}
[INFO] [stdout]    |                 ^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::exercise::*`
[INFO] [stdout]  --> src/main.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use crate::exercise::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust-learn`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unused import: `std::io::copy`
[INFO] [stdout]  --> src/demo/demo1.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::io::copy; // 也可已引入方法
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::*`
[INFO] [stdout]  --> src/demo/demo1.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::collections::*; // 引入模块下所有公共项
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]   --> src/demo/demo3_branches.rs:28:17
[INFO] [stdout]    |
[INFO] [stdout] 28 |     for elem in (1..9) {}
[INFO] [stdout]    |                 ^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::exercise::*`
[INFO] [stdout]  --> src/main.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use crate::exercise::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]  --> src/demo/demo10_err.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let f = match f {
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:67:11
[INFO] [stdout]    |
[INFO] [stdout] 67 | fn notify(item: impl Summary) {}
[INFO] [stdout]    |           ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:69:24
[INFO] [stdout]    |
[INFO] [stdout] 69 | fn notify2<T: Summary>(item: T, item2: T) {}
[INFO] [stdout]    |                        ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:69:33
[INFO] [stdout]    |
[INFO] [stdout] 69 | fn notify2<T: Summary>(item: T, item2: T) {}
[INFO] [stdout]    |                                 ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:71:12
[INFO] [stdout]    |
[INFO] [stdout] 71 | fn notify3(item: impl Summary + T2) -> impl Summary {
[INFO] [stdout]    |            ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:78:36
[INFO] [stdout]    |
[INFO] [stdout] 78 | fn notify4<T: Summary + T2, U: T2>(item: T, item2: U) {}
[INFO] [stdout]    |                                    ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:78:45
[INFO] [stdout]    |
[INFO] [stdout] 78 | fn notify4<T: Summary + T2, U: T2>(item: T, item2: U) {}
[INFO] [stdout]    |                                             ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:80:18
[INFO] [stdout]    |
[INFO] [stdout] 80 | fn notity5<T, U>(item: T, item2: U)
[INFO] [stdout]    |                  ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:80:27
[INFO] [stdout]    |
[INFO] [stdout] 80 | fn notity5<T, U>(item: T, item2: U)
[INFO] [stdout]    |                           ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]    --> src/demo/demo11_trait.rs:147:30
[INFO] [stdout]     |
[INFO] [stdout] 147 |     fn t<'a, 'b>(a: &'a str, b: &'b str) -> &'a str {
[INFO] [stdout]     |                              ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:94:12
[INFO] [stdout]    |
[INFO] [stdout] 94 |     fn new(x: T, y: T) {}
[INFO] [stdout]    |            ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:94:18
[INFO] [stdout]    |
[INFO] [stdout] 94 |     fn new(x: T, y: T) {}
[INFO] [stdout]    |                  ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:40:9
[INFO] [stdout]    |
[INFO] [stdout] 40 |     let f: f64 = 2.0;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `bl`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:42:9
[INFO] [stdout]    |
[INFO] [stdout] 42 |     let bl: bool = false;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_bl`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:44:9
[INFO] [stdout]    |
[INFO] [stdout] 44 |     let z: char = 'z'; // 字符类型用单引号表示,大小为4个字节,字符不是字符串
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:50:10
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let (x, y, z) = tup;
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:50:13
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let (x, y, z) = tup;
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:50:16
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let (x, y, z) = tup;
[INFO] [stdout]    |                ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let x = tup.0; // 第零位
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `arr`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:55:9
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let arr = [1, 2, 3, 4, 5];
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_arr`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `arr2`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:56:9
[INFO] [stdout]    |
[INFO] [stdout] 56 |     let arr2: [i32; 4] = [1, 2, 3, 4];
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_arr2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `arr3`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let arr3 = [1; 3]; // 指定初始值的数组 = [1,1,1]
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_arr3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `w`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:64:9
[INFO] [stdout]    |
[INFO] [stdout] 64 |     let w = {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_w`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `elem`
[INFO] [stdout]   --> src/demo/demo3_branches.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     for elem in (1..9) {}
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_elem`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s4`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:25:13
[INFO] [stdout]    |
[INFO] [stdout] 25 |         let s4 = takes_ownership(s3); // 引用类型将所有权移交给函数的参数,函数执行结束时 drop 了该内存块
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_s4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:36:9
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let s3 = &mut s2;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s4`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let s4 = &mut s2;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s5`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let s5 = &s2;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s5`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:48:9
[INFO] [stdout]    |
[INFO] [stdout] 48 |     let slice = &s[0..5];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice2`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |     let slice2 = &s[0..];
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_slice2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice3`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let slice3 = &s[..s.len()];
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_slice3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice4`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let slice4 = &s[..];
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_slice4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user3`
[INFO] [stdout]   --> src/demo/demo5_struct.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let user3 = User { age: 15, ..user2 }; // 可从user2中获取未设字段
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r`
[INFO] [stdout]   --> src/demo/demo5_struct.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let r = black.0;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_r`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `rectangle2`
[INFO] [stdout]   --> src/demo/demo5_struct.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let rectangle2 = Rectangle::factory(12, 50);
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_rectangle2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v6`
[INFO] [stdout]   --> src/demo/demo6_enum.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |     let v6 = IpAddrKind::V6(String::from("127.0.0.1"));
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_v6`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `name` is never read
[INFO] [stdout]   --> src/demo/demo6_enum.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let mut name: Option<String> = Some(String::from("nihao"));
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]  --> src/demo/demo7_vector.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     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: `v1`
[INFO] [stdout]  --> src/demo/demo7_vector.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let v1 = vec![1, 2, 3]; // vector 中仅允许一种类型的数据,具有类型推断
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_v1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `third`
[INFO] [stdout]  --> src/demo/demo7_vector.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let third: &i32 = &v2[2]; // 使用下标取值有可能导致 panic!,可使用 get(i) 取值
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_third`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v3`
[INFO] [stdout]   --> src/demo/demo7_vector.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let v3 = vec![Test::Age(1), Test::Name(String::from("name"))];
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_v3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `s` is assigned to, but never used
[INFO] [stdout]  --> src/demo/demo8_string.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let mut s = String::new();
[INFO] [stdout]   |         ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: consider using `_s` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `s` is never read
[INFO] [stdout]  --> src/demo/demo8_string.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 |     s = str1.to_string(); // to_string 方法，它能用于任何实现了 Display trait 的类型
[INFO] [stdout]   |     ^
[INFO] [stdout]   |
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]   --> src/demo/demo8_string.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let len = String::from("Hello").len(); // => 5 返回 Vec 的长度
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]   --> src/demo/demo8_string.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let len = String::from("Здравствуйте").len(); // => 24 [224,....23]
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/demo/demo8_string.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let s = &str3[0..4];
[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/demo/demo2_veriable.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let mut a: u8 = 255; // u8 类型最高值为255
[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: `f`
[INFO] [stdout]  --> src/demo/demo10_err.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let f = match f {
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:67:11
[INFO] [stdout]    |
[INFO] [stdout] 67 | fn notify(item: impl Summary) {}
[INFO] [stdout]    |           ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:69:24
[INFO] [stdout]    |
[INFO] [stdout] 69 | fn notify2<T: Summary>(item: T, item2: T) {}
[INFO] [stdout]    |                        ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:69:33
[INFO] [stdout]    |
[INFO] [stdout] 69 | fn notify2<T: Summary>(item: T, item2: T) {}
[INFO] [stdout]    |                                 ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:71:12
[INFO] [stdout]    |
[INFO] [stdout] 71 | fn notify3(item: impl Summary + T2) -> impl Summary {
[INFO] [stdout]    |            ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:78:36
[INFO] [stdout]    |
[INFO] [stdout] 78 | fn notify4<T: Summary + T2, U: T2>(item: T, item2: U) {}
[INFO] [stdout]    |                                    ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:78:45
[INFO] [stdout]    |
[INFO] [stdout] 78 | fn notify4<T: Summary + T2, U: T2>(item: T, item2: U) {}
[INFO] [stdout]    |                                             ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:80:18
[INFO] [stdout]    |
[INFO] [stdout] 80 | fn notity5<T, U>(item: T, item2: U)
[INFO] [stdout]    |                  ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:80:27
[INFO] [stdout]    |
[INFO] [stdout] 80 | fn notity5<T, U>(item: T, item2: U)
[INFO] [stdout]    |                           ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]    --> src/demo/demo11_trait.rs:147:30
[INFO] [stdout]     |
[INFO] [stdout] 147 |     fn t<'a, 'b>(a: &'a str, b: &'b str) -> &'a str {
[INFO] [stdout]     |                              ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:94:12
[INFO] [stdout]    |
[INFO] [stdout] 94 |     fn new(x: T, y: T) {}
[INFO] [stdout]    |            ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:94:18
[INFO] [stdout]    |
[INFO] [stdout] 94 |     fn new(x: T, y: T) {}
[INFO] [stdout]    |                  ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:40:9
[INFO] [stdout]    |
[INFO] [stdout] 40 |     let f: f64 = 2.0;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `bl`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:42:9
[INFO] [stdout]    |
[INFO] [stdout] 42 |     let bl: bool = false;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_bl`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:44:9
[INFO] [stdout]    |
[INFO] [stdout] 44 |     let z: char = 'z'; // 字符类型用单引号表示,大小为4个字节,字符不是字符串
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:50:10
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let (x, y, z) = tup;
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:50:13
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let (x, y, z) = tup;
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:50:16
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let (x, y, z) = tup;
[INFO] [stdout]    |                ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let x = tup.0; // 第零位
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `arr`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:55:9
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let arr = [1, 2, 3, 4, 5];
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_arr`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `arr2`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:56:9
[INFO] [stdout]    |
[INFO] [stdout] 56 |     let arr2: [i32; 4] = [1, 2, 3, 4];
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_arr2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `arr3`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let arr3 = [1; 3]; // 指定初始值的数组 = [1,1,1]
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_arr3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `w`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:64:9
[INFO] [stdout]    |
[INFO] [stdout] 64 |     let w = {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_w`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `elem`
[INFO] [stdout]   --> src/demo/demo3_branches.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     for elem in (1..9) {}
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_elem`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s4`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:25:13
[INFO] [stdout]    |
[INFO] [stdout] 25 |         let s4 = takes_ownership(s3); // 引用类型将所有权移交给函数的参数,函数执行结束时 drop 了该内存块
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_s4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:36:9
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let s3 = &mut s2;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s4`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let s4 = &mut s2;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s5`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let s5 = &s2;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s5`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:48:9
[INFO] [stdout]    |
[INFO] [stdout] 48 |     let slice = &s[0..5];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice2`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |     let slice2 = &s[0..];
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_slice2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice3`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let slice3 = &s[..s.len()];
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_slice3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice4`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let slice4 = &s[..];
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_slice4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user3`
[INFO] [stdout]   --> src/demo/demo5_struct.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let user3 = User { age: 15, ..user2 }; // 可从user2中获取未设字段
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r`
[INFO] [stdout]   --> src/demo/demo5_struct.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let r = black.0;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_r`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `rectangle2`
[INFO] [stdout]   --> src/demo/demo5_struct.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let rectangle2 = Rectangle::factory(12, 50);
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_rectangle2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v6`
[INFO] [stdout]   --> src/demo/demo6_enum.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |     let v6 = IpAddrKind::V6(String::from("127.0.0.1"));
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_v6`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `name` is never read
[INFO] [stdout]   --> src/demo/demo6_enum.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let mut name: Option<String> = Some(String::from("nihao"));
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]  --> src/demo/demo7_vector.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     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: `v1`
[INFO] [stdout]  --> src/demo/demo7_vector.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let v1 = vec![1, 2, 3]; // vector 中仅允许一种类型的数据,具有类型推断
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_v1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `third`
[INFO] [stdout]  --> src/demo/demo7_vector.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let third: &i32 = &v2[2]; // 使用下标取值有可能导致 panic!,可使用 get(i) 取值
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_third`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v3`
[INFO] [stdout]   --> src/demo/demo7_vector.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let v3 = vec![Test::Age(1), Test::Name(String::from("name"))];
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_v3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `s` is assigned to, but never used
[INFO] [stdout]  --> src/demo/demo8_string.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let mut s = String::new();
[INFO] [stdout]   |         ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: consider using `_s` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `s` is never read
[INFO] [stdout]  --> src/demo/demo8_string.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 |     s = str1.to_string(); // to_string 方法，它能用于任何实现了 Display trait 的类型
[INFO] [stdout]   |     ^
[INFO] [stdout]   |
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]   --> src/demo/demo8_string.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let len = String::from("Hello").len(); // => 5 返回 Vec 的长度
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]   --> src/demo/demo8_string.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let len = String::from("Здравствуйте").len(); // => 24 [224,....23]
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/demo/demo8_string.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let s = &str3[0..4];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Point1`
[INFO] [stdout]  --> src/demo/demo11_trait.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct Point1<T> {
[INFO] [stdout]   |        ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Point2`
[INFO] [stdout]  --> src/demo/demo11_trait.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 8 | struct Point2<T, U> {
[INFO] [stdout]   |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `x`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:14:8
[INFO] [stdout]    |
[INFO] [stdout] 14 |     fn x(&self) -> &T {
[INFO] [stdout]    |        ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `mixup`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:17:8
[INFO] [stdout]    |
[INFO] [stdout] 17 |     fn mixup<V, W>(self, other: Point2<V, W>) -> Point2<T, W> {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Result`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:25:6
[INFO] [stdout]    |
[INFO] [stdout] 25 | enum Result<T, U> {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:67:4
[INFO] [stdout]    |
[INFO] [stdout] 67 | fn notify(item: impl Summary) {}
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify2`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:69:4
[INFO] [stdout]    |
[INFO] [stdout] 69 | fn notify2<T: Summary>(item: T, item2: T) {}
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify3`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:71:4
[INFO] [stdout]    |
[INFO] [stdout] 71 | fn notify3(item: impl Summary + T2) -> impl Summary {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify4`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:78:4
[INFO] [stdout]    |
[INFO] [stdout] 78 | fn notify4<T: Summary + T2, U: T2>(item: T, item2: U) {}
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notity5`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:80:4
[INFO] [stdout]    |
[INFO] [stdout] 80 | fn notity5<T, U>(item: T, item2: U)
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `x`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:88:5
[INFO] [stdout]    |
[INFO] [stdout] 88 |     x: T,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `y`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:89:5
[INFO] [stdout]    |
[INFO] [stdout] 89 |     y: T,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `st`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:98:8
[INFO] [stdout]    |
[INFO] [stdout] 98 |     fn st() {}
[INFO] [stdout]    |        ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `privatefn`
[INFO] [stdout]  --> src/demo/demo12_tests.rs:5:4
[INFO] [stdout]   |
[INFO] [stdout] 5 | fn privatefn() -> i32 {
[INFO] [stdout]   |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `another_function`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:76:4
[INFO] [stdout]    |
[INFO] [stdout] 76 | fn another_function(x: i32, y: i32) -> i32 {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `dangling`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:70:4
[INFO] [stdout]    |
[INFO] [stdout] 70 | fn dangling() -> String {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `username`
[INFO] [stdout]   --> src/demo/demo5_struct.rs:71:5
[INFO] [stdout]    |
[INFO] [stdout] 71 |     username: String,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `email`
[INFO] [stdout]   --> src/demo/demo5_struct.rs:72:5
[INFO] [stdout]    |
[INFO] [stdout] 72 |     email: String,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `active`
[INFO] [stdout]   --> src/demo/demo5_struct.rs:74:5
[INFO] [stdout]    |
[INFO] [stdout] 74 |     active: bool,
[INFO] [stdout]    |     ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Ipv4`
[INFO] [stdout]   --> src/demo/demo6_enum.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 11 |     Ipv4(Ipv4Addr),
[INFO] [stdout]    |     ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Demo`
[INFO] [stdout]   --> src/demo/demo6_enum.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     Demo(Demo),         // 任意类型的值甚至枚举
[INFO] [stdout]    |     ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let mut a: u8 = 255; // u8 类型最高值为255
[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: 72 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Point1`
[INFO] [stdout]  --> src/demo/demo11_trait.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct Point1<T> {
[INFO] [stdout]   |        ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Point2`
[INFO] [stdout]  --> src/demo/demo11_trait.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 8 | struct Point2<T, U> {
[INFO] [stdout]   |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `x`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:14:8
[INFO] [stdout]    |
[INFO] [stdout] 14 |     fn x(&self) -> &T {
[INFO] [stdout]    |        ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `mixup`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:17:8
[INFO] [stdout]    |
[INFO] [stdout] 17 |     fn mixup<V, W>(self, other: Point2<V, W>) -> Point2<T, W> {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Result`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:25:6
[INFO] [stdout]    |
[INFO] [stdout] 25 | enum Result<T, U> {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:67:4
[INFO] [stdout]    |
[INFO] [stdout] 67 | fn notify(item: impl Summary) {}
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify2`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:69:4
[INFO] [stdout]    |
[INFO] [stdout] 69 | fn notify2<T: Summary>(item: T, item2: T) {}
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify3`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:71:4
[INFO] [stdout]    |
[INFO] [stdout] 71 | fn notify3(item: impl Summary + T2) -> impl Summary {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify4`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:78:4
[INFO] [stdout]    |
[INFO] [stdout] 78 | fn notify4<T: Summary + T2, U: T2>(item: T, item2: U) {}
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notity5`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:80:4
[INFO] [stdout]    |
[INFO] [stdout] 80 | fn notity5<T, U>(item: T, item2: U)
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `x`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:88:5
[INFO] [stdout]    |
[INFO] [stdout] 88 |     x: T,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `y`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:89:5
[INFO] [stdout]    |
[INFO] [stdout] 89 |     y: T,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `st`
[INFO] [stdout]   --> src/demo/demo11_trait.rs:98:8
[INFO] [stdout]    |
[INFO] [stdout] 98 |     fn st() {}
[INFO] [stdout]    |        ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `another_function`
[INFO] [stdout]   --> src/demo/demo2_veriable.rs:76:4
[INFO] [stdout]    |
[INFO] [stdout] 76 | fn another_function(x: i32, y: i32) -> i32 {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `dangling`
[INFO] [stdout]   --> src/demo/demo4_ownership.rs:70:4
[INFO] [stdout]    |
[INFO] [stdout] 70 | fn dangling() -> String {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `username`
[INFO] [stdout]   --> src/demo/demo5_struct.rs:71:5
[INFO] [stdout]    |
[INFO] [stdout] 71 |     username: String,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `email`
[INFO] [stdout]   --> src/demo/demo5_struct.rs:72:5
[INFO] [stdout]    |
[INFO] [stdout] 72 |     email: String,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `active`
[INFO] [stdout]   --> src/demo/demo5_struct.rs:74:5
[INFO] [stdout]    |
[INFO] [stdout] 74 |     active: bool,
[INFO] [stdout]    |     ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Ipv4`
[INFO] [stdout]   --> src/demo/demo6_enum.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 11 |     Ipv4(Ipv4Addr),
[INFO] [stdout]    |     ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Demo`
[INFO] [stdout]   --> src/demo/demo6_enum.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     Demo(Demo),         // 任意类型的值甚至枚举
[INFO] [stdout]    |     ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 71 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "1dacb88a7142a6a26dfabb075a0c9f5ba1fed8780ac57e24041df3c6c8fffe8e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1dacb88a7142a6a26dfabb075a0c9f5ba1fed8780ac57e24041df3c6c8fffe8e", kill_on_drop: false }`
[INFO] [stdout] 1dacb88a7142a6a26dfabb075a0c9f5ba1fed8780ac57e24041df3c6c8fffe8e