[INFO] cloning repository https://github.com/bookinstock/rust_example
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/bookinstock/rust_example" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbookinstock%2Frust_example", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbookinstock%2Frust_example'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] c83d144f2d500cd60a59da5019b4bc5ca7d2d36f
[INFO] checking bookinstock/rust_example against master#9610dfe5a9a731ced1ea4923ecbd0c57fe367898 for beta-170-4
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbookinstock%2Frust_example" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/bookinstock/rust_example on toolchain 9610dfe5a9a731ced1ea4923ecbd0c57fe367898
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+9610dfe5a9a731ced1ea4923ecbd0c57fe367898" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/bookinstock/rust_example
[INFO] finished tweaking git repo https://github.com/bookinstock/rust_example
[INFO] tweaked toml for git repo https://github.com/bookinstock/rust_example written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/bookinstock/rust_example 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" "+9610dfe5a9a731ced1ea4923ecbd0c57fe367898" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:19e73879b68f455e41552ea35293514db52ea292d993f571636dbffedb77a1ee" "/opt/rustwide/cargo-home/bin/cargo" "+9610dfe5a9a731ced1ea4923ecbd0c57fe367898" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 15f37224a8a36190745bf1ba8eec804396c34e5850956d4fc46a410b8cc420e8
[INFO] running `Command { std: "docker" "start" "-a" "15f37224a8a36190745bf1ba8eec804396c34e5850956d4fc46a410b8cc420e8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "15f37224a8a36190745bf1ba8eec804396c34e5850956d4fc46a410b8cc420e8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "15f37224a8a36190745bf1ba8eec804396c34e5850956d4fc46a410b8cc420e8", kill_on_drop: false }`
[INFO] [stdout] 15f37224a8a36190745bf1ba8eec804396c34e5850956d4fc46a410b8cc420e8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:19e73879b68f455e41552ea35293514db52ea292d993f571636dbffedb77a1ee" "/opt/rustwide/cargo-home/bin/cargo" "+9610dfe5a9a731ced1ea4923ecbd0c57fe367898" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2657ef4d9a36dd4c90da61b934168e7dde567af91a7c3f4831f03054099bda2b
[INFO] running `Command { std: "docker" "start" "-a" "2657ef4d9a36dd4c90da61b934168e7dde567af91a7c3f4831f03054099bda2b", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_example v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused label
[INFO] [stdout]    --> src/bin/control_flow.rs:119:9
[INFO] [stdout]     |
[INFO] [stdout] 119 |         'inner: loop {
[INFO] [stdout]     |         ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_labels)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `From` is imported redundantly
[INFO] [stdout]   --> src/bin/conversion.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |     use std::convert::From;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   --> /rustc/9610dfe5a9a731ced1ea4923ecbd0c57fe367898/library/std/src/prelude/mod.rs:115:13
[INFO] [stdout]    |
[INFO] [stdout]    = note: the item `From` is already defined here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: path statement with no effect
[INFO] [stdout]   --> src/bin/expression.rs:18:5
[INFO] [stdout]    |
[INFO] [stdout] 18 |     x;
[INFO] [stdout]    |     ^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(path_statements)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused arithmetic operation that must be used
[INFO] [stdout]   --> src/bin/expression.rs:19:5
[INFO] [stdout]    |
[INFO] [stdout] 19 |     x + 1;
[INFO] [stdout]    |     ^^^^^ the arithmetic operation produces a value
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let _ = x + 1;
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `ToString` is imported redundantly
[INFO] [stdout]    --> src/bin/conversion.rs:106:9
[INFO] [stdout]     |
[INFO] [stdout] 106 |     use std::string::ToString;
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    --> /rustc/9610dfe5a9a731ced1ea4923ecbd0c57fe367898/library/std/src/prelude/mod.rs:115:13
[INFO] [stdout]     |
[INFO] [stdout]     = note: the item `ToString` is already defined here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused arithmetic operation that must be used
[INFO] [stdout]   --> src/bin/expression.rs:36:9
[INFO] [stdout]    |
[INFO] [stdout] 36 |         2 * x;
[INFO] [stdout]    |         ^^^^^ the arithmetic operation produces a value
[INFO] [stdout]    |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 36 |         let _ = 2 * x;
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]    --> src/bin/control_flow.rs:125:9
[INFO] [stdout]     |
[INFO] [stdout] 122 |             break 'outer;
[INFO] [stdout]     |             ------------ any code following this expression is unreachable
[INFO] [stdout] ...
[INFO] [stdout] 125 |         println!("never reach");
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^ unreachable statement
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout]     = note: this warning originates in the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `my_string`
[INFO] [stdout]   --> src/bin/conversion.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let my_string = String::from(my_str);
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_my_string`
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/bin/conversion.rs:45:8
[INFO] [stdout]    |
[INFO] [stdout] 45 | #[warn(unused_variables)]
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_literal` is never used
[INFO] [stdout]    --> src/bin/pattern_matching.rs:113:4
[INFO] [stdout]     |
[INFO] [stdout] 113 | fn test_literal() {}
[INFO] [stdout]     |    ^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_array` is never used
[INFO] [stdout]    --> src/bin/pattern_matching.rs:115:4
[INFO] [stdout]     |
[INFO] [stdout] 115 | fn test_array() {}
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_enum` is never used
[INFO] [stdout]    --> src/bin/pattern_matching.rs:117:4
[INFO] [stdout]     |
[INFO] [stdout] 117 | fn test_enum() {}
[INFO] [stdout]     |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_stuct` is never used
[INFO] [stdout]    --> src/bin/pattern_matching.rs:119:4
[INFO] [stdout]     |
[INFO] [stdout] 119 | fn test_stuct() {}
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_variable` is never used
[INFO] [stdout]    --> src/bin/pattern_matching.rs:137:4
[INFO] [stdout]     |
[INFO] [stdout] 137 | fn test_variable() {}
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_wildcard` is never used
[INFO] [stdout]    --> src/bin/pattern_matching.rs:139:4
[INFO] [stdout]     |
[INFO] [stdout] 139 | fn test_wildcard() {}
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_placeholder` is never used
[INFO] [stdout]    --> src/bin/pattern_matching.rs:141:4
[INFO] [stdout]     |
[INFO] [stdout] 141 | fn test_placeholder() {}
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]    --> src/bin/generic.rs:217:9
[INFO] [stdout]     |
[INFO] [stdout] 217 |     let s = S(1);
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_literal` is never used
[INFO] [stdout]    --> src/bin/pattern_matching.rs:113:4
[INFO] [stdout]     |
[INFO] [stdout] 113 | fn test_literal() {}
[INFO] [stdout]     |    ^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_array` is never used
[INFO] [stdout]    --> src/bin/pattern_matching.rs:115:4
[INFO] [stdout]     |
[INFO] [stdout] 115 | fn test_array() {}
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_enum` is never used
[INFO] [stdout]    --> src/bin/pattern_matching.rs:117:4
[INFO] [stdout]     |
[INFO] [stdout] 117 | fn test_enum() {}
[INFO] [stdout]     |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_stuct` is never used
[INFO] [stdout]    --> src/bin/pattern_matching.rs:119:4
[INFO] [stdout]     |
[INFO] [stdout] 119 | fn test_stuct() {}
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_variable` is never used
[INFO] [stdout]    --> src/bin/pattern_matching.rs:137:4
[INFO] [stdout]     |
[INFO] [stdout] 137 | fn test_variable() {}
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_wildcard` is never used
[INFO] [stdout]    --> src/bin/pattern_matching.rs:139:4
[INFO] [stdout]     |
[INFO] [stdout] 139 | fn test_wildcard() {}
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_placeholder` is never used
[INFO] [stdout]    --> src/bin/pattern_matching.rs:141:4
[INFO] [stdout]     |
[INFO] [stdout] 141 | fn test_placeholder() {}
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `vec2`
[INFO] [stdout]    --> src/bin/function.rs:391:9
[INFO] [stdout]     |
[INFO] [stdout] 391 |     let vec2 = vec![4, 5, 6];
[INFO] [stdout]     |         ^^^^ help: if this is intentional, prefix it with an underscore: `_vec2`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/bin/scope.rs:88:9
[INFO] [stdout]    |
[INFO] [stdout] 88 |     let x = ToDrop;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `x` and `y` are never read
[INFO] [stdout]   --> src/bin/generic.rs:44:5
[INFO] [stdout]    |
[INFO] [stdout] 43 | struct A {
[INFO] [stdout]    |        - fields in this struct
[INFO] [stdout] 44 |     x: i32,
[INFO] [stdout]    |     ^
[INFO] [stdout] 45 |     y: i32,
[INFO] [stdout]    |     ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `A` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `S` is never constructed
[INFO] [stdout]    --> src/bin/generic.rs:135:12
[INFO] [stdout]     |
[INFO] [stdout] 135 |     struct S; // 具体类型 `S`
[INFO] [stdout]     |            ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `GenericVal` is never constructed
[INFO] [stdout]    --> src/bin/generic.rs:136:12
[INFO] [stdout]     |
[INFO] [stdout] 136 |     struct GenericVal<T>(T); // 泛型类型 `GenericVal`
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `printer` is never used
[INFO] [stdout]    --> src/bin/generic.rs:210:8
[INFO] [stdout]     |
[INFO] [stdout] 210 |     fn printer<T: Display>(t: T) {
[INFO] [stdout]     |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: multiple variants are never constructed
[INFO] [stdout]    --> src/bin/control_flow.rs:247:9
[INFO] [stdout]     |
[INFO] [stdout] 246 |     enum Color {
[INFO] [stdout]     |          ----- variants in this enum
[INFO] [stdout] 247 |         Red,
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 248 |         Blue,
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] 249 |         Green,
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout] 250 |         RGB(u32, u32, u32),
[INFO] [stdout] 251 |         HSV(u32, u32, u32),
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 252 |         HSL(u32, u32, u32),
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 253 |         CMY(u32, u32, u32),
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 254 |         CMYK(u32, u32, u32, u32),
[INFO] [stdout]     |         ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]    --> src/bin/generic.rs:217:9
[INFO] [stdout]     |
[INFO] [stdout] 217 |     let s = S(1);
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `ttt` is never used
[INFO] [stdout]    --> src/bin/hello.rs:107:4
[INFO] [stdout]     |
[INFO] [stdout] 107 | fn ttt() {
[INFO] [stdout]     |    ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `f` is never used
[INFO] [stdout]    --> src/bin/hello.rs:120:4
[INFO] [stdout]     |
[INFO] [stdout] 120 | fn f() {
[INFO] [stdout]     |    ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test` is never used
[INFO] [stdout]    --> src/bin/hello.rs:124:4
[INFO] [stdout]     |
[INFO] [stdout] 124 | fn test() {
[INFO] [stdout]     |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `try_debug_trait` is never used
[INFO] [stdout]    --> src/bin/hello.rs:159:4
[INFO] [stdout]     |
[INFO] [stdout] 159 | fn try_debug_trait() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `red`, `green`, and `blue` are never read
[INFO] [stdout]    --> src/bin/hello.rs:243:9
[INFO] [stdout]     |
[INFO] [stdout] 242 |     struct Color {
[INFO] [stdout]     |            ----- fields in this struct
[INFO] [stdout] 243 |         red: u8,
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 244 |         green: u8,
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout] 245 |         blue: u8,
[INFO] [stdout]     |         ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `Color` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0601]: `main` function not found in crate `test`
[INFO] [stdout]   --> src/bin/test.rs:13:4
[INFO] [stdout]    |
[INFO] [stdout] 13 | */
[INFO] [stdout]    |    ^ consider adding a `main` function to `src/bin/test.rs`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[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 E0601`.
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ref_x`
[INFO] [stdout]    --> src/bin/scope.rs:401:13
[INFO] [stdout]     |
[INFO] [stdout] 401 |         let ref_x = &x;
[INFO] [stdout]     |             ^^^^^ help: if this is intentional, prefix it with an underscore: `_ref_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/bin/scope.rs:405:13
[INFO] [stdout]     |
[INFO] [stdout] 405 |         let mut ref_x = &mut x;
[INFO] [stdout]     |             ----^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `ps_ref` is never used
[INFO] [stdout]    --> src/bin/scope.rs:444:4
[INFO] [stdout]     |
[INFO] [stdout] 444 | fn ps_ref() {
[INFO] [stdout]     |    ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0433]: failed to resolve: use of undeclared crate or module `futures`
[INFO] [stdout]   --> src/bin/async.rs:10:5
[INFO] [stdout]    |
[INFO] [stdout] 10 | use futures::executor::block_on;
[INFO] [stdout]    |     ^^^^^^^ use of undeclared crate or module `futures`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `x` and `y` are never read
[INFO] [stdout]   --> src/bin/generic.rs:44:5
[INFO] [stdout]    |
[INFO] [stdout] 43 | struct A {
[INFO] [stdout]    |        - fields in this struct
[INFO] [stdout] 44 |     x: i32,
[INFO] [stdout]    |     ^
[INFO] [stdout] 45 |     y: i32,
[INFO] [stdout]    |     ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `A` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `S` is never constructed
[INFO] [stdout]    --> src/bin/generic.rs:135:12
[INFO] [stdout]     |
[INFO] [stdout] 135 |     struct S; // 具体类型 `S`
[INFO] [stdout]     |            ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `GenericVal` is never constructed
[INFO] [stdout]    --> src/bin/generic.rs:136:12
[INFO] [stdout]     |
[INFO] [stdout] 136 |     struct GenericVal<T>(T); // 泛型类型 `GenericVal`
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_example` (bin "test") due to 2 previous errors
[INFO] [stdout] warning: function `printer` is never used
[INFO] [stdout]    --> src/bin/generic.rs:210:8
[INFO] [stdout]     |
[INFO] [stdout] 210 |     fn printer<T: Display>(t: T) {
[INFO] [stdout]     |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: this method call resolves to `<&[T; N] as IntoIterator>::into_iter` (due to backwards compatibility), but will resolve to <[T; N] as IntoIterator>::into_iter in Rust 2021
[INFO] [stdout]    --> src/bin/function.rs:431:16
[INFO] [stdout]     |
[INFO] [stdout] 431 |         array2.into_iter().find(|&&x| x == 2)
[INFO] [stdout]     |                ^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this changes meaning in Rust 2021
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/IntoIterator-for-arrays.html>
[INFO] [stdout]     = note: `#[warn(array_into_iter)]` on by default
[INFO] [stdout] help: use `.iter()` instead of `.into_iter()` to avoid ambiguity
[INFO] [stdout]     |
[INFO] [stdout] 431 |         array2.iter().find(|&&x| x == 2)
[INFO] [stdout]     |                ~~~~
[INFO] [stdout] help: or use `IntoIterator::into_iter(..)` instead of `.into_iter()` to explicitly iterate by value
[INFO] [stdout]     |
[INFO] [stdout] 431 |         IntoIterator::into_iter(array2).find(|&&x| x == 2)
[INFO] [stdout]     |         ++++++++++++++++++++++++      ~
[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 E0433`.
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_example` (bin "async") due to 2 previous errors
[INFO] [stdout] error[E0601]: `main` function not found in crate `r#trait`
[INFO] [stdout]   --> src/bin/trait.rs:15:4
[INFO] [stdout]    |
[INFO] [stdout] 15 | */
[INFO] [stdout]    |    ^ consider adding a `main` function to `src/bin/trait.rs`
[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 E0601`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_example` (bin "trait") due to 2 previous errors
[INFO] [stdout] warning: unused variable: `noisy_unused_variable`
[INFO] [stdout]   --> src/bin/var_binding.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let noisy_unused_variable = 2u32;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_noisy_unused_variable`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `name` and `age` are never read
[INFO] [stdout]   --> src/bin/custom_type.rs:25:5
[INFO] [stdout]    |
[INFO] [stdout] 24 | struct Person<'a> {
[INFO] [stdout]    |        ------ fields in this struct
[INFO] [stdout] 25 |     name: &'a str,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 26 |     age: u8,
[INFO] [stdout]    |     ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Person` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Nil` is never constructed
[INFO] [stdout]   --> src/bin/custom_type.rs:30:8
[INFO] [stdout]    |
[INFO] [stdout] 30 | struct Nil;
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `ttt` is never used
[INFO] [stdout]    --> src/bin/hello.rs:107:4
[INFO] [stdout]     |
[INFO] [stdout] 107 | fn ttt() {
[INFO] [stdout]     |    ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `f` is never used
[INFO] [stdout]    --> src/bin/hello.rs:120:4
[INFO] [stdout]     |
[INFO] [stdout] 120 | fn f() {
[INFO] [stdout]     |    ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test` is never used
[INFO] [stdout]    --> src/bin/hello.rs:124:4
[INFO] [stdout]     |
[INFO] [stdout] 124 | fn test() {
[INFO] [stdout]     |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `try_debug_trait` is never used
[INFO] [stdout]    --> src/bin/hello.rs:159:4
[INFO] [stdout]     |
[INFO] [stdout] 159 | fn try_debug_trait() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `red`, `green`, and `blue` are never read
[INFO] [stdout]    --> src/bin/hello.rs:243:9
[INFO] [stdout]     |
[INFO] [stdout] 242 |     struct Color {
[INFO] [stdout]     |            ----- fields in this struct
[INFO] [stdout] 243 |         red: u8,
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 244 |         green: u8,
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout] 245 |         blue: u8,
[INFO] [stdout]     |         ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `Color` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "2657ef4d9a36dd4c90da61b934168e7dde567af91a7c3f4831f03054099bda2b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2657ef4d9a36dd4c90da61b934168e7dde567af91a7c3f4831f03054099bda2b", kill_on_drop: false }`
[INFO] [stdout] 2657ef4d9a36dd4c90da61b934168e7dde567af91a7c3f4831f03054099bda2b
