[INFO] cloning repository https://github.com/mxdzs0612/rust-by-practice
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mxdzs0612/rust-by-practice" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmxdzs0612%2Frust-by-practice", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmxdzs0612%2Frust-by-practice'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ab89d3528e8232391f1761d19227230912c60869
[INFO] testing mxdzs0612/rust-by-practice against try#c2e32f1c9652b13ed99608599c1e855462f421f3 for pr-146098-7
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmxdzs0612%2Frust-by-practice" "/workspace/builds/worker-3-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/mxdzs0612/rust-by-practice
[INFO] finished tweaking git repo https://github.com/mxdzs0612/rust-by-practice
[INFO] tweaked toml for git repo https://github.com/mxdzs0612/rust-by-practice written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/mxdzs0612/rust-by-practice on toolchain c2e32f1c9652b13ed99608599c1e855462f421f3
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/mxdzs0612/rust-by-practice 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" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2af37218645ba89a5f28f01de73ff2eb98ffac60b73cdb8d91e92b9353e6008a
[INFO] running `Command { std: "docker" "start" "-a" "2af37218645ba89a5f28f01de73ff2eb98ffac60b73cdb8d91e92b9353e6008a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2af37218645ba89a5f28f01de73ff2eb98ffac60b73cdb8d91e92b9353e6008a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2af37218645ba89a5f28f01de73ff2eb98ffac60b73cdb8d91e92b9353e6008a", kill_on_drop: false }`
[INFO] [stdout] 2af37218645ba89a5f28f01de73ff2eb98ffac60b73cdb8d91e92b9353e6008a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4fbccb0706556abb863e2e208b7d6e65f6c9c31d211f368f10d8e0395722e6e6
[INFO] running `Command { std: "docker" "start" "-a" "4fbccb0706556abb863e2e208b7d6e65f6c9c31d211f368f10d8e0395722e6e6", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust_by_practice v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: function `complain` is never used
[INFO] [stdout]  --> src/front_of_house/serving.rs:8:4
[INFO] [stdout]   |
[INFO] [stdout] 8 | fn complain() {} 
[INFO] [stdout]   |    ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/8-1-8.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |     Qux(u32),
[INFO] [stdout]    |     --- ^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[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] 25 -     Qux(u32),
[INFO] [stdout] 25 +     Qux(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Bar` and `Baz` are never constructed
[INFO] [stdout]   --> src/bin/8-1-8.rs:23:5
[INFO] [stdout]    |
[INFO] [stdout] 22 | enum Foo {
[INFO] [stdout]    |      --- variants in this enum
[INFO] [stdout] 23 |     Bar,
[INFO] [stdout]    |     ^^^
[INFO] [stdout] 24 |     Baz,
[INFO] [stdout]    |     ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ele`
[INFO] [stdout]   --> src/bin/13-1-2.rs:41:9
[INFO] [stdout]    |
[INFO] [stdout] 41 |     let ele = v[2];
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_ele`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ele`
[INFO] [stdout]   --> src/bin/13-1-2.rs:42:9
[INFO] [stdout]    |
[INFO] [stdout] 42 |     let ele = v.get(2).unwrap();
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_ele`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/bin/13-1-2.rs:45:9
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let v = production_rate_per_hour(2);
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `ImportantExcerpt` is never constructed
[INFO] [stdout]   --> src/bin/17-3-2.rs:19:8
[INFO] [stdout]    |
[INFO] [stdout] 19 | struct ImportantExcerpt<'a> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `announce_and_return_part` is never used
[INFO] [stdout]   --> src/bin/17-3-2.rs:24:8
[INFO] [stdout]    |
[INFO] [stdout] 23 | impl<'a : 'b, 'b> ImportantExcerpt<'a> {
[INFO] [stdout]    | -------------------------------------- method in this implementation
[INFO] [stdout] 24 |     fn announce_and_return_part(&'a self, announcement: &'b str) -> &'b str {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `fly` is never used
[INFO] [stdout]   --> src/bin/10-4-2.rs:50:8
[INFO] [stdout]    |
[INFO] [stdout] 49 | impl Duck {
[INFO] [stdout]    | --------- method in this implementation
[INFO] [stdout] 50 |     fn fly(&self) {
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `fly` is never used
[INFO] [stdout]   --> src/bin/10-4-2.rs:56:8
[INFO] [stdout]    |
[INFO] [stdout] 55 | impl Swan {
[INFO] [stdout]    | --------- method in this implementation
[INFO] [stdout] 56 |     fn fly(&self) {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/bin/4-1-2.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let v: u16 = 38_u8 as u16;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `CliError` is never used
[INFO] [stdout]   --> src/bin/12-2-3.rs:35:6
[INFO] [stdout]    |
[INFO] [stdout] 35 | enum CliError {
[INFO] [stdout]    |      ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `open_and_parse_file` is never used
[INFO] [stdout]   --> src/bin/12-2-3.rs:52:4
[INFO] [stdout]    |
[INFO] [stdout] 52 | fn open_and_parse_file(file_name: &str) -> Result<i32, CliError> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused label
[INFO] [stdout]   --> src/bin/7-11.rs:43:9
[INFO] [stdout]    |
[INFO] [stdout] 43 |         'inner2: loop {
[INFO] [stdout]    |         ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_labels)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer`
[INFO] [stdout]   --> src/bin/10-1-3.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let integer = Point { x: 5, y: 10 };
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `float`
[INFO] [stdout]   --> src/bin/10-1-3.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let float = Point { x: 1.0, y: 4.0 };
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_float`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `x` and `y` are never read
[INFO] [stdout]   --> src/bin/10-1-3.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 14 | struct Point<T>{
[INFO] [stdout]    |        ----- fields in this struct
[INFO] [stdout] 15 |     x: T,
[INFO] [stdout]    |     ^
[INFO] [stdout] 16 |     y: T,
[INFO] [stdout]    |     ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::fmt::Result`
[INFO] [stdout]  --> src/bin/14-3-1.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 | use std::fmt::Result;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::Result as IoResult`
[INFO] [stdout]  --> src/bin/14-3-1.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::io::Result as IoResult;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]    --> src/bin/10-4-1.rs:115:8
[INFO] [stdout]     |
[INFO] [stdout] 115 |     if (i == 1) {
[INFO] [stdout]     |        ^      ^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout] 115 -     if (i == 1) {
[INFO] [stdout] 115 +     if i == 1 {
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `fly` is never used
[INFO] [stdout]   --> src/bin/10-4-1.rs:76:8
[INFO] [stdout]    |
[INFO] [stdout] 75 | impl Swan {
[INFO] [stdout]    | --------- method in this implementation
[INFO] [stdout] 76 |     fn fly(&self) {
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Person` is never constructed
[INFO] [stdout]   --> src/bin/6-4-5.rs:18:8
[INFO] [stdout]    |
[INFO] [stdout] 18 | struct Person {
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `build_person` is never used
[INFO] [stdout]   --> src/bin/6-4-5.rs:24:4
[INFO] [stdout]    |
[INFO] [stdout] 24 | fn build_person(name: String, age: u8) -> Person {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]   --> src/bin/8-1-7.rs:25:8
[INFO] [stdout]    |
[INFO] [stdout] 25 |     if let Foo::Bar(i) = a {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this pattern will always match, so the `if let` is useless
[INFO] [stdout]    = help: consider replacing the `if let` with a `let`
[INFO] [stdout]    = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u2`
[INFO] [stdout]   --> src/bin/6-4-6.rs:41:9
[INFO] [stdout]    |
[INFO] [stdout] 41 |     let u2 = set_email(u1);
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_u2`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `active`, `username`, `email`, and `sign_in_count` are never read
[INFO] [stdout]   --> src/bin/6-4-6.rs:28:5
[INFO] [stdout]    |
[INFO] [stdout] 27 | struct User {
[INFO] [stdout]    |        ---- fields in this struct
[INFO] [stdout] 28 |     active: bool,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout] 29 |     username: String,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout] 30 |     email: String,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 31 |     sign_in_count: u64,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `call_on_ref_zero` is never used
[INFO] [stdout]   --> src/bin/17-3-4.rs:23:4
[INFO] [stdout]    |
[INFO] [stdout] 23 | fn call_on_ref_zero<F>(f: F) where F: for<'a> Fn(&'a i32) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/bin/12-1-2.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let v = 1000 as u8;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/bin/17-1-5.rs:39:9
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let y: &i32 = &_x;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/5-2-7.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let mut s = String::from("hello");
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `TrafficLight` is never constructed
[INFO] [stdout]   --> src/bin/9-3.rs:18:8
[INFO] [stdout]    |
[INFO] [stdout] 18 | struct TrafficLight {
[INFO] [stdout]    |        ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `show_state` and `change_state` are never used
[INFO] [stdout]   --> src/bin/9-3.rs:24:12
[INFO] [stdout]    |
[INFO] [stdout] 22 | impl TrafficLight {
[INFO] [stdout]    | ----------------- methods in this implementation
[INFO] [stdout] 23 |     // 使用 `Self` 填空
[INFO] [stdout] 24 |     pub fn show_state(self: &Self)  {
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 29 |     pub fn change_state(&mut self) {
[INFO] [stdout]    |            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Quit`, `Write`, and `ChangeColor` are never constructed
[INFO] [stdout]   --> src/bin/6-6-3.rs:23:5
[INFO] [stdout]    |
[INFO] [stdout] 22 | enum Message {
[INFO] [stdout]    |      ------- variants in this enum
[INFO] [stdout] 23 |     Quit,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 24 |     Move { x: i32, y: i32 },
[INFO] [stdout] 25 |     Write(String),
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 26 |     ChangeColor(i32, i32, i32),
[INFO] [stdout]    |     ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `manager` is never read
[INFO] [stdout]   --> src/bin/17-3-6.rs:69:5
[INFO] [stdout]    |
[INFO] [stdout] 68 | struct Interface<'b, 'a: 'b> {
[INFO] [stdout]    |        --------- field in this struct
[INFO] [stdout] 69 |     manager: &'b mut Manager<'a>
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `y` is assigned to, but never used
[INFO] [stdout]   --> src/bin/4-1-1.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let mut y = 5;
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: consider using `_y` instead
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/bin/4-1-1.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let z = 10; // 这里 z 的类型是? 
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `y` is never read
[INFO] [stdout]   --> src/bin/4-1-1.rs:21:5
[INFO] [stdout]    |
[INFO] [stdout] 21 |     y = x;
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `longest` is never used
[INFO] [stdout]   --> src/bin/17-1-3.rs:56:4
[INFO] [stdout]    |
[INFO] [stdout] 56 | fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/bin/10-3-8.rs:45:8
[INFO] [stdout]    |
[INFO] [stdout] 44 | impl<T> Pair<T> {
[INFO] [stdout]    | --------------- associated function in this implementation
[INFO] [stdout] 45 |     fn new(x: T, y: T) -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/5-2-9.rs:23:18
[INFO] [stdout]    |
[INFO] [stdout] 23 | fn borrow_object(s: &String) {}
[INFO] [stdout]    |                  ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/bin/7-8.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     for i in 0..=100 {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/bin/17-1-10.rs:48:32
[INFO] [stdout]    |
[INFO] [stdout] 48 | fn longest<'a, 'b>(x: &'a str, y: &'b str) -> &'a str {
[INFO] [stdout]    |                                ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `nput` is never used
[INFO] [stdout]   --> src/bin/17-1-10.rs:42:4
[INFO] [stdout]    |
[INFO] [stdout] 42 | fn nput<>(x: &i32) {
[INFO] [stdout]    |    ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `pass` is never used
[INFO] [stdout]   --> src/bin/17-1-10.rs:46:4
[INFO] [stdout]    |
[INFO] [stdout] 46 | fn pass<>(x: &i32) -> &i32 { x }
[INFO] [stdout]    |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `longest` is never used
[INFO] [stdout]   --> src/bin/17-1-10.rs:48:4
[INFO] [stdout]    |
[INFO] [stdout] 48 | fn longest<'a, 'b>(x: &'a str, y: &'b str) -> &'a str {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Owner` is never constructed
[INFO] [stdout]   --> src/bin/17-1-10.rs:52:8
[INFO] [stdout]    |
[INFO] [stdout] 52 | struct Owner(i32);
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `add_one` and `print` are never used
[INFO] [stdout]   --> src/bin/17-1-10.rs:55:8
[INFO] [stdout]    |
[INFO] [stdout] 54 | impl Owner {
[INFO] [stdout]    | ---------- methods in this implementation
[INFO] [stdout] 55 |     fn add_one(&mut self) { self.0 += 1; }
[INFO] [stdout]    |        ^^^^^^^
[INFO] [stdout] 56 |     fn print(&self) {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Person` is never constructed
[INFO] [stdout]   --> src/bin/17-1-10.rs:61:8
[INFO] [stdout]    |
[INFO] [stdout] 61 | struct Person<'a> {
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Either` is never used
[INFO] [stdout]   --> src/bin/17-1-10.rs:66:6
[INFO] [stdout]    |
[INFO] [stdout] 66 | enum Either<'a> {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `thing`
[INFO] [stdout]   --> src/bin/19-9.rs:11:11
[INFO] [stdout]    |
[INFO] [stdout] 11 | fn foobar(thing: &dyn Display) {}
[INFO] [stdout]    |           ^^^^^ help: if this is intentional, prefix it with an underscore: `_thing`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `thing`
[INFO] [stdout]   --> src/bin/19-9.rs:13:12
[INFO] [stdout]    |
[INFO] [stdout] 13 | fn foobar2(thing: Box<dyn Display>) {}    
[INFO] [stdout]    |            ^^^^^ help: if this is intentional, prefix it with an underscore: `_thing`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `foobar` is never used
[INFO] [stdout]   --> src/bin/19-9.rs:11:4
[INFO] [stdout]    |
[INFO] [stdout] 11 | fn foobar(thing: &dyn Display) {}
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `foobar2` is never used
[INFO] [stdout]   --> src/bin/19-9.rs:13:4
[INFO] [stdout]    |
[INFO] [stdout] 13 | fn foobar2(thing: Box<dyn Display>) {}    
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/bin/7-7.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     for i in 0..=100 {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/18-1-4.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let s = example_closure(String::from("hello"));
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `n`
[INFO] [stdout]   --> src/bin/18-1-4.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let n = example_closure("5".to_string());
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_n`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Red` and `Green` are never constructed
[INFO] [stdout]   --> src/bin/9-6.rs:27:5
[INFO] [stdout]    |
[INFO] [stdout] 26 | enum TrafficLightColor {
[INFO] [stdout]    |      ----------------- variants in this enum
[INFO] [stdout] 27 |     Red,
[INFO] [stdout]    |     ^^^
[INFO] [stdout] 28 |     Yellow,
[INFO] [stdout] 29 |     Green,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `TrafficLightColor` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `invalid_output` is never used
[INFO] [stdout]   --> src/bin/17-1-4.rs:11:4
[INFO] [stdout]    |
[INFO] [stdout] 11 | fn invalid_output() -> String { 
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0499]: cannot borrow `s` as mutable more than once at a time
[INFO] [stdout]   --> src/bin/5-2-11.rs:18:14
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let r1 = &mut s;
[INFO] [stdout]    |              ------ first mutable borrow occurs here
[INFO] [stdout] 18 |     let r2 = &mut s;
[INFO] [stdout]    |              ^^^^^^ second mutable borrow occurs here
[INFO] [stdout] ...
[INFO] [stdout] 22 |     println!("{} {}", r1, r2);
[INFO] [stdout]    |                       -- first borrow later used here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0499`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_by_practice` (bin "5-2-11") due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unused import: `self`
[INFO] [stdout]   --> src/bin/10-3-3.rs:20:16
[INFO] [stdout]    |
[INFO] [stdout] 20 | use std::ops::{self, Mul};
[INFO] [stdout]    |                ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/bin/4-1-7.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let x = 1_000.000_1; // f64
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/bin/4-1-7.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let y: f32 = 0.12; // f32
[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/bin/4-1-7.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let z = 0.01_f64; // f64
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/16-2-1.rs:34:18
[INFO] [stdout]    |
[INFO] [stdout] 34 | struct Structure(i32);
[INFO] [stdout]    |        --------- ^^^
[INFO] [stdout]    |        |
[INFO] [stdout]    |        field in this struct
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider removing this field
[INFO] [stdout]    = note: `Structure` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `width` and `height` are never read
[INFO] [stdout]   --> src/bin/6-4-7.rs:26:5
[INFO] [stdout]    |
[INFO] [stdout] 25 | struct Rectangle {
[INFO] [stdout]    |        --------- fields in this struct
[INFO] [stdout] 26 |     width: u32,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 27 |     height: u32,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Rectangle` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "4fbccb0706556abb863e2e208b7d6e65f6c9c31d211f368f10d8e0395722e6e6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4fbccb0706556abb863e2e208b7d6e65f6c9c31d211f368f10d8e0395722e6e6", kill_on_drop: false }`
[INFO] [stdout] 4fbccb0706556abb863e2e208b7d6e65f6c9c31d211f368f10d8e0395722e6e6