[INFO] cloning repository https://github.com/zgblog/rust-study
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/zgblog/rust-study" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzgblog%2Frust-study", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzgblog%2Frust-study'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 979810785a1ae2349cfb7e0529b386adef18ccd9
[INFO] testing zgblog/rust-study against try#8de4c7234dd9b97c9d76b58671343fdbbc9a433e+target=x86_64-unknown-linux-musl for musl_upgrade_1_2_5_with_libc_patch_0
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzgblog%2Frust-study" "/workspace/builds/worker-3-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/zgblog/rust-study
[INFO] finished tweaking git repo https://github.com/zgblog/rust-study
[INFO] tweaked toml for git repo https://github.com/zgblog/rust-study written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/zgblog/rust-study on toolchain 8de4c7234dd9b97c9d76b58671343fdbbc9a433e
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/zgblog/rust-study already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f67179b5277b6e61955a9dbb1ceb98c964a09d88de00f01abdb9e1ac57d276bc
[INFO] running `Command { std: "docker" "start" "-a" "f67179b5277b6e61955a9dbb1ceb98c964a09d88de00f01abdb9e1ac57d276bc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f67179b5277b6e61955a9dbb1ceb98c964a09d88de00f01abdb9e1ac57d276bc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f67179b5277b6e61955a9dbb1ceb98c964a09d88de00f01abdb9e1ac57d276bc", kill_on_drop: false }`
[INFO] [stdout] f67179b5277b6e61955a9dbb1ceb98c964a09d88de00f01abdb9e1ac57d276bc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "build" "--frozen" "--message-format=json" "--target" "x86_64-unknown-linux-musl", kill_on_drop: false }`
[INFO] [stdout] 1e4d476835cc3781baa41de433147b0bd8bf5df4b9f3d0ec7bbff6820dfc6340
[INFO] running `Command { std: "docker" "start" "-a" "1e4d476835cc3781baa41de433147b0bd8bf5df4b9f3d0ec7bbff6820dfc6340", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.155
[INFO] [stderr]    Compiling ppv-lite86 v0.2.17
[INFO] [stderr]    Compiling getrandom v0.2.15
[INFO] [stderr]    Compiling rand_core v0.6.4
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling rand v0.8.5
[INFO] [stderr]    Compiling study v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field `seasonal_fruit` is never read
[INFO] [stdout]  --> src/lib.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     pub struct Breakfast{
[INFO] [stdout]   |                --------- field in this struct
[INFO] [stdout] 3 |         pub toast: String,
[INFO] [stdout] 4 |         seasonal_fruit: String
[INFO] [stdout]   |         ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Appetizer` is never used
[INFO] [stdout]   --> src/lib.rs:16:14
[INFO] [stdout]    |
[INFO] [stdout] 16 |     pub enum Appetizer {}
[INFO] [stdout]    |              ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `seat_at_table` is never used
[INFO] [stdout]   --> src/lib.rs:23:12
[INFO] [stdout]    |
[INFO] [stdout] 23 |         fn seat_at_table() {}
[INFO] [stdout]    |            ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `take_order` is never used
[INFO] [stdout]   --> src/lib.rs:27:12
[INFO] [stdout]    |
[INFO] [stdout] 27 |         fn take_order() {}
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `take_payment` is never used
[INFO] [stdout]   --> src/lib.rs:29:12
[INFO] [stdout]    |
[INFO] [stdout] 29 |         fn take_payment() {}
[INFO] [stdout]    |            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `todo` is never used
[INFO] [stdout]  --> src/back_of_house/hosting.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn todo() {}
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Cons` and `Nil`
[INFO] [stdout]   --> src/bin/smartpointer/refcell_test.rs:77:19
[INFO] [stdout]    |
[INFO] [stdout] 77 | use crate::List::{Cons, Nil};
[INFO] [stdout]    |                   ^^^^  ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0601]: `main` function not found in crate `refcell`
[INFO] [stdout]   --> src/bin/smartpointer/refcell_test.rs:94:2
[INFO] [stdout]    |
[INFO] [stdout] 94 | }
[INFO] [stdout]    |  ^ consider adding a `main` function to `src/bin/smartpointer/refcell_test.rs`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collect/string_test.rs:9:13
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let mut s = String::new();
[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: unused variable: `s`
[INFO] [stdout]   --> src/bin/collect/string_test.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let s = data.to_string();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/collect/string_test.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let s = "initial contents".to_string();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/collect/string_test.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let s = String::from("initial contents");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collect/string_test.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let hello = String::from("السلام عليكم");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collect/string_test.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let hello = String::from("Dobrý den");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collect/string_test.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let hello = String::from("Hello");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collect/string_test.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let hello = String::from("שָׁלוֹם");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collect/string_test.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let hello = String::from("नमस्ते");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collect/string_test.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |     let hello = String::from("こんにちは");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collect/string_test.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let hello = String::from("안녕하세요");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collect/string_test.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let hello = String::from("你好");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collect/string_test.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let hello = String::from("Olá");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collect/string_test.rs:29:9
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let hello = String::from("Здравствуйте");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collect/string_test.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let hello = String::from("Hola");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/bin/collect/string_test.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let mut s = String::new();
[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: trait `Summary_2` should have an upper camel case name
[INFO] [stdout]   --> src/bin/generics/trait_test.rs:23:7
[INFO] [stdout]    |
[INFO] [stdout] 23 | trait Summary_2 {
[INFO] [stdout]    |       ^^^^^^^^^ help: convert the identifier to upper camel case: `Summary2`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_camel_case_types)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Summary_3` should have an upper camel case name
[INFO] [stdout]   --> src/bin/generics/trait_test.rs:29:7
[INFO] [stdout]    |
[INFO] [stdout] 29 | trait Summary_3 {
[INFO] [stdout]    |       ^^^^^^^^^ help: convert the identifier to upper camel case: `Summary3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `result`
[INFO] [stdout]  --> src/bin/io/command.rs:1:43
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::{env, error::Error, fs, process, result};
[INFO] [stdout]   |                                           ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_number`
[INFO] [stdout]  --> src/bin/optional.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let some_number = Some(5);
[INFO] [stdout]   |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_number`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_string`
[INFO] [stdout]  --> src/bin/optional.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let some_string = Some("A String");
[INFO] [stdout]   |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `absend_number`
[INFO] [stdout]  --> src/bin/optional.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let absend_number: Option<i32> = None;
[INFO] [stdout]   |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_absend_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `none`
[INFO] [stdout]   --> src/bin/optional.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let none = plus_one(None);
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_none`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0601`.
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/bin/generics/trait_test.rs:90:19
[INFO] [stdout]    |
[INFO] [stdout] 90 | fn notify_5<T, U>(t: T, u: U) where T: Display + Clone, U: Clone + Debug {
[INFO] [stdout]    |                   ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> src/bin/generics/trait_test.rs:90:25
[INFO] [stdout]    |
[INFO] [stdout] 90 | fn notify_5<T, U>(t: T, u: U) where T: Display + Clone, U: Clone + Debug {
[INFO] [stdout]    |                         ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Summary_2` is never used
[INFO] [stdout]   --> src/bin/generics/trait_test.rs:23:7
[INFO] [stdout]    |
[INFO] [stdout] 23 | trait Summary_2 {
[INFO] [stdout]    |       ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Summary_3` is never used
[INFO] [stdout]   --> src/bin/generics/trait_test.rs:29:7
[INFO] [stdout]    |
[INFO] [stdout] 29 | trait Summary_3 {
[INFO] [stdout]    |       ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify` is never used
[INFO] [stdout]   --> src/bin/generics/trait_test.rs:65:4
[INFO] [stdout]    |
[INFO] [stdout] 65 | fn notify(item: impl Summary) {
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify_2` is never used
[INFO] [stdout]   --> src/bin/generics/trait_test.rs:72:4
[INFO] [stdout]    |
[INFO] [stdout] 72 | fn notify_2<T: Summary>(item: T) {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify_3` is never used
[INFO] [stdout]   --> src/bin/generics/trait_test.rs:79:4
[INFO] [stdout]    |
[INFO] [stdout] 79 | fn notify_3(item: impl Summary + Display) {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify_4` is never used
[INFO] [stdout]   --> src/bin/generics/trait_test.rs:83:4
[INFO] [stdout]    |
[INFO] [stdout] 83 | fn notify_4<T: Summary + Display>(item: T) {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify_5` is never used
[INFO] [stdout]   --> src/bin/generics/trait_test.rs:90:4
[INFO] [stdout]    |
[INFO] [stdout] 90 | fn notify_5<T, U>(t: T, u: U) where T: Display + Clone, U: Clone + Debug {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]  --> src/bin/error/result_test.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: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/bin/generics/gen_test.rs:90:11
[INFO] [stdout]    |
[INFO] [stdout] 90 |         if(self.x >= self.y) {
[INFO] [stdout]    |           ^                ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 90 -         if(self.x >= self.y) {
[INFO] [stdout] 90 +         if self.x >= self.y {
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `return_summarizable` is never used
[INFO] [stdout]   --> src/bin/generics/trait_test.rs:97:4
[INFO] [stdout]    |
[INFO] [stdout] 97 | fn return_summarizable() -> impl Summary {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]  --> src/bin/borrow.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let len = update(&mut s2);
[INFO] [stdout]   |         ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]  --> src/bin/slice.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let hello = &s[..5];
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/error/result_test.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let f = File::open("hello.txt").unwrap_or_else(|error| {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `world`
[INFO] [stdout]   --> src/bin/slice.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let world = &s[6..];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_world`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `whold`
[INFO] [stdout]   --> src/bin/slice.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let whold = &s[..];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_whold`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `study` (bin "refcell") due to 1 previous error; 1 warning emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unused variable: `p3`
[INFO] [stdout]   --> src/bin/generics/gen_test.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let p3 = p1.mixup(p2);
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_p3`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/bin/slice.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let mut s = String::from("Hello world!");
[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 doc comment
[INFO] [stdout]   --> src/bin/closures/closure_test.rs:25:5
[INFO] [stdout]    |
[INFO] [stdout] 25 | /     /**
[INFO] [stdout] 26 | |      * 闭包，语法 |xxx| {}
[INFO] [stdout] 27 | |      */
[INFO] [stdout]    | |_______^
[INFO] [stdout] 28 | /     let mut expensive_result = Cacher::new(|num| {
[INFO] [stdout] 29 | |         println!("calculating slowly...");
[INFO] [stdout] 30 | |         thread::sleep(Duration::from_secs(2));
[INFO] [stdout] 31 | |         num
[INFO] [stdout] 32 | |     });
[INFO] [stdout]    | |_______- rustdoc does not generate documentation for statements
[INFO] [stdout]    |
[INFO] [stdout]    = help: use `/* */` for a plain comment
[INFO] [stdout]    = note: `#[warn(unused_doc_comments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/error/result_test.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let f = File::open("hello.txt").unwrap();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/error/result_test.rs:40:9
[INFO] [stdout]    |
[INFO] [stdout] 40 |     let f = File::open("hello.txt").expect("Failed to open hello.txt");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `result_2` is never used
[INFO] [stdout]   --> src/bin/error/result_test.rs:20:4
[INFO] [stdout]    |
[INFO] [stdout] 20 | fn result_2() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `result_3` is never used
[INFO] [stdout]   --> src/bin/error/result_test.rs:33:4
[INFO] [stdout]    |
[INFO] [stdout] 33 | fn result_3() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `result_4` is never used
[INFO] [stdout]   --> src/bin/error/result_test.rs:38:4
[INFO] [stdout]    |
[INFO] [stdout] 38 | fn result_4() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `result_5` is never used
[INFO] [stdout]   --> src/bin/error/result_test.rs:46:4
[INFO] [stdout]    |
[INFO] [stdout] 46 | fn result_5() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `result_6` is never used
[INFO] [stdout]   --> src/bin/error/result_test.rs:64:4
[INFO] [stdout]    |
[INFO] [stdout] 64 | fn result_6() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]  --> src/bin/smartpointer/mem_leak.rs:7:10
[INFO] [stdout]   |
[INFO] [stdout] 7 |     Cons(i32, RefCell<Rc<List>>),
[INFO] [stdout]   |     ---- ^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     field in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` 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] 7 -     Cons(i32, RefCell<Rc<List>>),
[INFO] [stdout] 7 +     Cons((), RefCell<Rc<List>>),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `value` and `children` are never read
[INFO] [stdout]   --> src/bin/smartpointer/mem_leak.rs:47:5
[INFO] [stdout]    |
[INFO] [stdout] 46 | struct Node {
[INFO] [stdout]    |        ---- fields in this struct
[INFO] [stdout] 47 |     value: i32,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 48 |     children: RefCell<Vec<Rc<Node>>>,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Node` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `largest_i32` is never used
[INFO] [stdout]   --> src/bin/generics/gen_test.rs:16:4
[INFO] [stdout]    |
[INFO] [stdout] 16 | fn largest_i32(list: &[i32]) -> i32 {
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `largest_char` is never used
[INFO] [stdout]   --> src/bin/generics/gen_test.rs:26:4
[INFO] [stdout]    |
[INFO] [stdout] 26 | fn largest_char(list: &[char]) -> char {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `x` is never used
[INFO] [stdout]   --> src/bin/generics/gen_test.rs:58:8
[INFO] [stdout]    |
[INFO] [stdout] 57 | impl<T, U> Point<T, U> {
[INFO] [stdout]    | ---------------------- method in this implementation
[INFO] [stdout] 58 |     fn x(&self) -> &T {
[INFO] [stdout]    |        ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Pair` is never constructed
[INFO] [stdout]   --> src/bin/generics/gen_test.rs:75:8
[INFO] [stdout]    |
[INFO] [stdout] 75 | struct Pair<T> {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/bin/generics/gen_test.rs:81:8
[INFO] [stdout]    |
[INFO] [stdout] 80 | impl<T> Pair<T> {
[INFO] [stdout]    | --------------- associated function in this implementation
[INFO] [stdout] 81 |     fn new(x: T, y: T) -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `cmp_display` is never used
[INFO] [stdout]   --> src/bin/generics/gen_test.rs:89:8
[INFO] [stdout]    |
[INFO] [stdout] 88 | impl<T: Display + PartialOrd> Pair<T> {
[INFO] [stdout]    | ------------------------------------- method in this implementation
[INFO] [stdout] 89 |     fn cmp_display(&self) {
[INFO] [stdout]    |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/bin/slice.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let slice = &a[1..3];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_world2` is never used
[INFO] [stdout]   --> src/bin/slice.rs:25:4
[INFO] [stdout]    |
[INFO] [stdout] 25 | fn first_world2(s: &str) -> &str {  // 字符串切片作为函数参数
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `array_slice` is never used
[INFO] [stdout]   --> src/bin/slice.rs:35:4
[INFO] [stdout]    |
[INFO] [stdout] 35 | fn array_slice() {
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `simulated_expensive_calculation` is never used
[INFO] [stdout]   --> src/bin/closures/closure_test.rs:18:4
[INFO] [stdout]    |
[INFO] [stdout] 18 | fn simulated_expensive_calculation(intensity: u32) -> u32 {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]  --> src/bin/function.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let x = 5;
[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: unused variable: `number2`
[INFO] [stdout]   --> src/bin/function.rs:44:9
[INFO] [stdout]    |
[INFO] [stdout] 44 |     let number2 = if true {5} else {6};
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_number2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "1e4d476835cc3781baa41de433147b0bd8bf5df4b9f3d0ec7bbff6820dfc6340", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1e4d476835cc3781baa41de433147b0bd8bf5df4b9f3d0ec7bbff6820dfc6340", kill_on_drop: false }`
[INFO] [stdout] 1e4d476835cc3781baa41de433147b0bd8bf5df4b9f3d0ec7bbff6820dfc6340