[INFO] cloning repository https://github.com/infynyxx/hello_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/infynyxx/hello_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Finfynyxx%2Fhello_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Finfynyxx%2Fhello_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3263fa66c0626cb1b75efda7b8002e79aeb0d8c1
[INFO] checking infynyxx/hello_rust against master#507271bc119683008ec719ecee48814e8ac86c65 for pr-146440
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Finfynyxx%2Fhello_rust" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/infynyxx/hello_rust
[INFO] finished tweaking git repo https://github.com/infynyxx/hello_rust
[INFO] tweaked toml for git repo https://github.com/infynyxx/hello_rust written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/infynyxx/hello_rust on toolchain 507271bc119683008ec719ecee48814e8ac86c65
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+507271bc119683008ec719ecee48814e8ac86c65" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/infynyxx/hello_rust 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" "+507271bc119683008ec719ecee48814e8ac86c65" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded remove_dir_all v0.5.2
[INFO] [stderr]   Downloaded tempfile v3.1.0
[INFO] [stderr]   Downloaded getrandom v0.1.14
[INFO] [stderr]   Downloaded redox_syscall v0.1.56
[INFO] [stderr]   Downloaded log v0.4.8
[INFO] [stderr]   Downloaded assert_approx_eq v1.1.0
[INFO] [stderr]   Downloaded ppv-lite86 v0.2.8
[INFO] [stderr]   Downloaded libc v0.2.70
[INFO] [stderr]   Downloaded winapi v0.3.8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+507271bc119683008ec719ecee48814e8ac86c65" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8998aa5377920ca1a893d874e8aec8be2eec7f34b0fdd0501c10274930fc9b01
[INFO] running `Command { std: "docker" "start" "-a" "8998aa5377920ca1a893d874e8aec8be2eec7f34b0fdd0501c10274930fc9b01", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8998aa5377920ca1a893d874e8aec8be2eec7f34b0fdd0501c10274930fc9b01", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8998aa5377920ca1a893d874e8aec8be2eec7f34b0fdd0501c10274930fc9b01", kill_on_drop: false }`
[INFO] [stdout] 8998aa5377920ca1a893d874e8aec8be2eec7f34b0fdd0501c10274930fc9b01
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+507271bc119683008ec719ecee48814e8ac86c65" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9db4074904457b0e576967f65533445218c3a7e7835a470f479ed409dc557240
[INFO] running `Command { std: "docker" "start" "-a" "9db4074904457b0e576967f65533445218c3a7e7835a470f479ed409dc557240", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.70
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]     Checking ppv-lite86 v0.2.8
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking remove_dir_all v0.5.2
[INFO] [stderr]     Checking assert_approx_eq v1.1.0
[INFO] [stderr]     Checking minigrep v0.1.0 (/opt/rustwide/workdir/minigrep)
[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 tempfile v3.1.0
[INFO] [stderr]     Checking playground v0.1.0 (/opt/rustwide/workdir/playground)
[INFO] [stdout] warning: unused import: `std::fs::File`
[INFO] [stdout]  --> playground/src/error_handling.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::fs::File;
[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`
[INFO] [stdout]  --> playground/src/error_handling.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io;
[INFO] [stdout]   |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::Read`
[INFO] [stdout]  --> playground/src/error_handling.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::io::Read;
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::Write`
[INFO] [stdout]  --> playground/src/error_handling.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::io::Write;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `tempfile::tempdir`
[INFO] [stdout]  --> playground/src/error_handling.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use tempfile::tempdir;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused doc comment
[INFO] [stdout]   --> playground/src/generics.rs:67:5
[INFO] [stdout]    |
[INFO] [stdout] 67 | /     /**
[INFO] [stdout] 68 | |     if (switch) {
[INFO] [stdout] 69 | |         NewsArticle {
[INFO] [stdout] 70 | |             headline: "Hello World".to_string(),
[INFO] [stdout] ...  |
[INFO] [stdout] 82 | |     }**/
[INFO] [stdout]    | |________^
[INFO] [stdout] 83 | /     Tweet {
[INFO] [stdout] 84 | |         username: "infynyxx".to_string(),
[INFO] [stdout] 85 | |         content: "Hello World!".to_string(),
[INFO] [stdout] 86 | |         reply: false,
[INFO] [stdout] 87 | |         retweet: false,
[INFO] [stdout] 88 | |     }
[INFO] [stdout]    | |_____- rustdoc does not generate documentation for expressions
[INFO] [stdout]    |
[INFO] [stdout]    = help: use `/* */` for a plain comment
[INFO] [stdout]    = note: `#[warn(unused_doc_comments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `super::*`
[INFO] [stdout]   --> playground/src/iter.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     use super::*;
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused doc comment
[INFO] [stdout]   --> playground/src/generics.rs:67:5
[INFO] [stdout]    |
[INFO] [stdout] 67 | /     /**
[INFO] [stdout] 68 | |     if (switch) {
[INFO] [stdout] 69 | |         NewsArticle {
[INFO] [stdout] 70 | |             headline: "Hello World".to_string(),
[INFO] [stdout] ...  |
[INFO] [stdout] 82 | |     }**/
[INFO] [stdout]    | |________^
[INFO] [stdout] 83 | /     Tweet {
[INFO] [stdout] 84 | |         username: "infynyxx".to_string(),
[INFO] [stdout] 85 | |         content: "Hello World!".to_string(),
[INFO] [stdout] 86 | |         reply: false,
[INFO] [stdout] 87 | |         retweet: false,
[INFO] [stdout] 88 | |     }
[INFO] [stdout]    | |_____- rustdoc does not generate documentation for expressions
[INFO] [stdout]    |
[INFO] [stdout]    = help: use `/* */` for a plain comment
[INFO] [stdout]    = note: `#[warn(unused_doc_comments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> playground/src/generics.rs:58:24
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn some_function<T, U>(t: T, u: U) -> i32
[INFO] [stdout]    |                        ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> playground/src/generics.rs:58:30
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn some_function<T, U>(t: T, u: U) -> i32
[INFO] [stdout]    |                              ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `switch`
[INFO] [stdout]   --> playground/src/generics.rs:66:21
[INFO] [stdout]    |
[INFO] [stdout] 66 | fn get_summarizable(switch: bool) -> impl Summary {
[INFO] [stdout]    |                     ^^^^^^ help: if this is intentional, prefix it with an underscore: `_switch`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `x` and `y` are never read
[INFO] [stdout]   --> playground/src/lib.rs:19:5
[INFO] [stdout]    |
[INFO] [stdout] 18 | pub struct Circle {
[INFO] [stdout]    |            ------ fields in this struct
[INFO] [stdout] 19 |     x: f64,
[INFO] [stdout]    |     ^
[INFO] [stdout] 20 |     y: f64,
[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 `Cacher` is never constructed
[INFO] [stdout]  --> playground/src/closures.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | struct Cacher<T>
[INFO] [stdout]   |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new` and `value` are never used
[INFO] [stdout]   --> playground/src/closures.rs:16:8
[INFO] [stdout]    |
[INFO] [stdout] 12 | / impl<T> Cacher<T>
[INFO] [stdout] 13 | | where
[INFO] [stdout] 14 | |     T: Fn(u32) -> u32,
[INFO] [stdout]    | |______________________- associated items in this implementation
[INFO] [stdout] 15 |   {
[INFO] [stdout] 16 |       fn new(calculation: T) -> Cacher<T> {
[INFO] [stdout]    |          ^^^
[INFO] [stdout] ...
[INFO] [stdout] 23 |       fn value(&mut self, arg: u32) -> u32 {
[INFO] [stdout]    |          ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `generate_workout` is never used
[INFO] [stdout]   --> playground/src/closures.rs:35:4
[INFO] [stdout]    |
[INFO] [stdout] 35 | fn generate_workout(intensity: u32, random_number: u32) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `IpAddress` is never used
[INFO] [stdout]  --> playground/src/enums.rs:2:6
[INFO] [stdout]   |
[INFO] [stdout] 2 | enum IpAddress {
[INFO] [stdout]   |      ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `call` is never used
[INFO] [stdout]  --> playground/src/enums.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 7 | impl IpAddress {
[INFO] [stdout]   | -------------- method in this implementation
[INFO] [stdout] 8 |     fn call(&self) {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Point` is never constructed
[INFO] [stdout]  --> playground/src/generics.rs:7:8
[INFO] [stdout]   |
[INFO] [stdout] 7 | struct Point<T> {
[INFO] [stdout]   |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `distance_from_origin` is never used
[INFO] [stdout]   --> playground/src/generics.rs:13:8
[INFO] [stdout]    |
[INFO] [stdout] 12 | impl Point<f32> {
[INFO] [stdout]    | --------------- method in this implementation
[INFO] [stdout] 13 |     fn distance_from_origin(&self) -> f32 {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Summary` is never used
[INFO] [stdout]   --> playground/src/generics.rs:18:7
[INFO] [stdout]    |
[INFO] [stdout] 18 | trait Summary {
[INFO] [stdout]    |       ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `NewsArticle` is never constructed
[INFO] [stdout]   --> playground/src/generics.rs:22:8
[INFO] [stdout]    |
[INFO] [stdout] 22 | struct NewsArticle {
[INFO] [stdout]    |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Tweet` is never constructed
[INFO] [stdout]   --> playground/src/generics.rs:35:8
[INFO] [stdout]    |
[INFO] [stdout] 35 | struct Tweet {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify` is never used
[INFO] [stdout]   --> playground/src/generics.rs:54:4
[INFO] [stdout]    |
[INFO] [stdout] 54 | fn notify<T: Summary + Display>(item: T) -> String {
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_function` is never used
[INFO] [stdout]   --> playground/src/generics.rs:58:4
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn some_function<T, U>(t: T, u: U) -> i32
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `get_summarizable` is never used
[INFO] [stdout]   --> playground/src/generics.rs:66:4
[INFO] [stdout]    |
[INFO] [stdout] 66 | fn get_summarizable(switch: bool) -> impl Summary {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `largest` is never used
[INFO] [stdout]   --> playground/src/generics.rs:91:4
[INFO] [stdout]    |
[INFO] [stdout] 91 | fn largest<T: PartialOrd + Copy>(list: &[T]) -> T {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Shoe` is never constructed
[INFO] [stdout]  --> playground/src/iter.rs:2:8
[INFO] [stdout]   |
[INFO] [stdout] 2 | struct Shoe {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `shows_in_my_size` is never used
[INFO] [stdout]  --> playground/src/iter.rs:7:4
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn shows_in_my_size(shoes: Vec<Shoe>, shoe_size: u32) -> Vec<Shoe> {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Counter` is never constructed
[INFO] [stdout]   --> playground/src/iter.rs:11:8
[INFO] [stdout]    |
[INFO] [stdout] 11 | struct Counter {
[INFO] [stdout]    |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> playground/src/iter.rs:16:8
[INFO] [stdout]    |
[INFO] [stdout] 15 | impl Counter {
[INFO] [stdout]    | ------------ associated function in this implementation
[INFO] [stdout] 16 |     fn new() -> Counter {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `longest` is never used
[INFO] [stdout]   --> playground/src/lifetime.rs:25:4
[INFO] [stdout]    |
[INFO] [stdout] 25 | fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `ImportantExcerpt` is never constructed
[INFO] [stdout]   --> playground/src/lifetime.rs:51:8
[INFO] [stdout]    |
[INFO] [stdout] 51 | struct ImportantExcerpt<'a> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `announce_and_return_part` is never used
[INFO] [stdout]   --> playground/src/lifetime.rs:56:8
[INFO] [stdout]    |
[INFO] [stdout] 55 | impl<'a> ImportantExcerpt<'a> {
[INFO] [stdout]    | ----------------------------- method in this implementation
[INFO] [stdout] 56 |     fn announce_and_return_part(&self, s: &str) -> &str {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `longest_with_announcement` is never used
[INFO] [stdout]   --> playground/src/lifetime.rs:62:4
[INFO] [stdout]    |
[INFO] [stdout] 62 | fn longest_with_announcement<'a, T: std::fmt::Display>(x: &'a str, y: &'a str, ann: T) -> &'a str {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `width` and `height` are never read
[INFO] [stdout]  --> playground/src/structs.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct Rectangle {
[INFO] [stdout]   |            --------- fields in this struct
[INFO] [stdout] 4 |     width: u32,
[INFO] [stdout]   |     ^^^^^
[INFO] [stdout] 5 |     height: u32,
[INFO] [stdout]   |     ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `Rectangle` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `area`, `can_hold`, and `square` are never used
[INFO] [stdout]   --> playground/src/structs.rs:9:8
[INFO] [stdout]    |
[INFO] [stdout]  8 | impl Rectangle {
[INFO] [stdout]    | -------------- associated items in this implementation
[INFO] [stdout]  9 |     fn area(&self) -> u32 {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 13 |     fn can_hold(&self, other: Rectangle) -> bool {
[INFO] [stdout]    |        ^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 17 |     fn square(size: u32) -> Rectangle {
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> playground/src/generics.rs:58:24
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn some_function<T, U>(t: T, u: U) -> i32
[INFO] [stdout]    |                        ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> playground/src/generics.rs:58:30
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn some_function<T, U>(t: T, u: U) -> i32
[INFO] [stdout]    |                              ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `switch`
[INFO] [stdout]   --> playground/src/generics.rs:66:21
[INFO] [stdout]    |
[INFO] [stdout] 66 | fn get_summarizable(switch: bool) -> impl Summary {
[INFO] [stdout]    |                     ^^^^^^ help: if this is intentional, prefix it with an underscore: `_switch`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `x` and `y` are never read
[INFO] [stdout]   --> playground/src/lib.rs:19:5
[INFO] [stdout]    |
[INFO] [stdout] 18 | pub struct Circle {
[INFO] [stdout]    |            ------ fields in this struct
[INFO] [stdout] 19 |     x: f64,
[INFO] [stdout]    |     ^
[INFO] [stdout] 20 |     y: f64,
[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 `Cacher` is never constructed
[INFO] [stdout]  --> playground/src/closures.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | struct Cacher<T>
[INFO] [stdout]   |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new` and `value` are never used
[INFO] [stdout]   --> playground/src/closures.rs:16:8
[INFO] [stdout]    |
[INFO] [stdout] 12 | / impl<T> Cacher<T>
[INFO] [stdout] 13 | | where
[INFO] [stdout] 14 | |     T: Fn(u32) -> u32,
[INFO] [stdout]    | |______________________- associated items in this implementation
[INFO] [stdout] 15 |   {
[INFO] [stdout] 16 |       fn new(calculation: T) -> Cacher<T> {
[INFO] [stdout]    |          ^^^
[INFO] [stdout] ...
[INFO] [stdout] 23 |       fn value(&mut self, arg: u32) -> u32 {
[INFO] [stdout]    |          ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `generate_workout` is never used
[INFO] [stdout]   --> playground/src/closures.rs:35:4
[INFO] [stdout]    |
[INFO] [stdout] 35 | fn generate_workout(intensity: u32, random_number: u32) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `call` is never used
[INFO] [stdout]  --> playground/src/enums.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 7 | impl IpAddress {
[INFO] [stdout]   | -------------- method in this implementation
[INFO] [stdout] 8 |     fn call(&self) {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `NewsArticle` is never constructed
[INFO] [stdout]   --> playground/src/generics.rs:22:8
[INFO] [stdout]    |
[INFO] [stdout] 22 | struct NewsArticle {
[INFO] [stdout]    |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `reply` and `retweet` are never read
[INFO] [stdout]   --> playground/src/generics.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 35 | struct Tweet {
[INFO] [stdout]    |        ----- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 38 |     pub reply: bool,
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout] 39 |     pub retweet: bool,
[INFO] [stdout]    |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_function` is never used
[INFO] [stdout]   --> playground/src/generics.rs:58:4
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn some_function<T, U>(t: T, u: U) -> i32
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `get_summarizable` is never used
[INFO] [stdout]   --> playground/src/generics.rs:66:4
[INFO] [stdout]    |
[INFO] [stdout] 66 | fn get_summarizable(switch: bool) -> impl Summary {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `ImportantExcerpt` is never constructed
[INFO] [stdout]   --> playground/src/lifetime.rs:51:8
[INFO] [stdout]    |
[INFO] [stdout] 51 | struct ImportantExcerpt<'a> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `announce_and_return_part` is never used
[INFO] [stdout]   --> playground/src/lifetime.rs:56:8
[INFO] [stdout]    |
[INFO] [stdout] 55 | impl<'a> ImportantExcerpt<'a> {
[INFO] [stdout]    | ----------------------------- method in this implementation
[INFO] [stdout] 56 |     fn announce_and_return_part(&self, s: &str) -> &str {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_V4` should have a snake case name
[INFO] [stdout]   --> playground/src/enums.rs:14:4
[INFO] [stdout]    |
[INFO] [stdout] 14 | fn test_V4() {
[INFO] [stdout]    |    ^^^^^^^ help: convert the identifier to snake case (notice the capitalization): `test_v4`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` (part of `#[warn(nonstandard_style)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_V6` should have a snake case name
[INFO] [stdout]   --> playground/src/enums.rs:24:4
[INFO] [stdout]    |
[INFO] [stdout] 24 | fn test_V6() {
[INFO] [stdout]    |    ^^^^^^^ help: convert the identifier to snake case (notice the capitalization): `test_v6`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> playground/src/main.rs:46:9
[INFO] [stdout]    |
[INFO] [stdout] 46 |         channel.send(result);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 46 |         let _ = channel.send(result);
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 3.14s
[INFO] running `Command { std: "docker" "inspect" "9db4074904457b0e576967f65533445218c3a7e7835a470f479ed409dc557240", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9db4074904457b0e576967f65533445218c3a7e7835a470f479ed409dc557240", kill_on_drop: false }`
[INFO] [stdout] 9db4074904457b0e576967f65533445218c3a7e7835a470f479ed409dc557240
