[INFO] cloning repository https://github.com/frostRed/head_first_design_patterns_rust [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/frostRed/head_first_design_patterns_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FfrostRed%2Fhead_first_design_patterns_rust", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FfrostRed%2Fhead_first_design_patterns_rust'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] 779447adaf64ad62404312d51b8363b8602c3552 [INFO] testing frostRed/head_first_design_patterns_rust against master#cdb45c87e2cd43495379f7e867e3cc15dcee9f93 for pr-145838-1 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FfrostRed%2Fhead_first_design_patterns_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/frostRed/head_first_design_patterns_rust [INFO] finished tweaking git repo https://github.com/frostRed/head_first_design_patterns_rust [INFO] tweaked toml for git repo https://github.com/frostRed/head_first_design_patterns_rust written to /workspace/builds/worker-6-tc1/source/Cargo.toml [INFO] validating manifest of git repo https://github.com/frostRed/head_first_design_patterns_rust on toolchain cdb45c87e2cd43495379f7e867e3cc15dcee9f93 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] crate git repo https://github.com/frostRed/head_first_design_patterns_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" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] [stderr] Downloading crates ... [INFO] [stderr] Downloaded lazy_static v1.2.0 [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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 6549bb5651e5e71041f4f04a452c1066ab22de678eeeccc1f8b2d161be8576b1 [INFO] running `Command { std: "docker" "start" "-a" "6549bb5651e5e71041f4f04a452c1066ab22de678eeeccc1f8b2d161be8576b1", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "6549bb5651e5e71041f4f04a452c1066ab22de678eeeccc1f8b2d161be8576b1", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "6549bb5651e5e71041f4f04a452c1066ab22de678eeeccc1f8b2d161be8576b1", kill_on_drop: false }` [INFO] [stdout] 6549bb5651e5e71041f4f04a452c1066ab22de678eeeccc1f8b2d161be8576b1 [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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "build" "--frozen" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] f8b81442ebf7bf830228c7c2c9680da578b81ab96bae2b753674af61cdc41a9c [INFO] running `Command { std: "docker" "start" "-a" "f8b81442ebf7bf830228c7c2c9680da578b81ab96bae2b753674af61cdc41a9c", kill_on_drop: false }` [INFO] [stderr] Compiling lazy_static v1.2.0 [INFO] [stderr] Compiling head_first_design_patterns v0.1.0 (/opt/rustwide/workdir) [INFO] [stdout] warning: unnecessary braces around block return value [INFO] [stdout] --> src/singleton.rs:50:49 [INFO] [stdout] | [INFO] [stdout] 50 | pub static ref C: RwLock = { RwLock::new(ChocolateBoiler::new()) }; [INFO] [stdout] | ^^ ^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_braces)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] help: remove these braces [INFO] [stdout] | [INFO] [stdout] 50 - pub static ref C: RwLock = { RwLock::new(ChocolateBoiler::new()) }; [INFO] [stdout] 50 + pub static ref C: RwLock = RwLock::new(ChocolateBoiler::new()); [INFO] [stdout] | [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused import: `Read` [INFO] [stdout] --> src/template_method.rs:5:21 [INFO] [stdout] | [INFO] [stdout] 5 | use std::io::{self, Read}; [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 imports: `Beverage`, `DarkRost`, `Espresso`, `HouseBlend`, `Mocha`, `Soy`, and `Whip` [INFO] [stdout] --> src/lib.rs:19:24 [INFO] [stdout] | [INFO] [stdout] 19 | use crate::decorator::{Beverage, DarkRost, Espresso, HouseBlend, Mocha, Soy, Whip}; [INFO] [stdout] | ^^^^^^^^ ^^^^^^^^ ^^^^^^^^ ^^^^^^^^^^ ^^^^^ ^^^ ^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused imports: `ChicagoPizzaStore`, `NYPizzaStore`, `PizzaStore`, and `Pizza` [INFO] [stdout] --> src/lib.rs:20:29 [INFO] [stdout] | [INFO] [stdout] 20 | use crate::factory_method::{ChicagoPizzaStore, NYPizzaStore, Pizza, PizzaStore}; [INFO] [stdout] | ^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^ ^^^^^ ^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused imports: `CurrentConditionsDisplay`, `Subject`, and `WeatherDate` [INFO] [stdout] --> src/lib.rs:21:23 [INFO] [stdout] | [INFO] [stdout] 21 | use crate::observer::{CurrentConditionsDisplay, Subject, WeatherDate}; [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^ ^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused imports: `C` and `ChocolateBoiler` [INFO] [stdout] --> src/lib.rs:22:24 [INFO] [stdout] | [INFO] [stdout] 22 | use crate::singleton::{ChocolateBoiler, C}; [INFO] [stdout] | ^^^^^^^^^^^^^^^ ^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused imports: `Duck`, `FlyBehavior`, `FlyRocketPowered`, `MallardDuck`, and `ModelDuck` [INFO] [stdout] --> src/lib.rs:23:23 [INFO] [stdout] | [INFO] [stdout] 23 | use crate::strategy::{Duck, FlyBehavior, FlyRocketPowered, MallardDuck, ModelDuck}; [INFO] [stdout] | ^^^^ ^^^^^^^^^^^ ^^^^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error[E0635]: unknown feature `vec_remove_item` [INFO] [stdout] --> src/lib.rs:1:12 [INFO] [stdout] | [INFO] [stdout] 1 | #![feature(vec_remove_item)] [INFO] [stdout] | ^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:83:36 [INFO] [stdout] | [INFO] [stdout] 83 | quack_behavior: Rc>>, [INFO] [stdout] | ^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 83 | quack_behavior: Rc>>, [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:84:34 [INFO] [stdout] | [INFO] [stdout] 84 | fly_behavior: Rc>>, [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 84 | fly_behavior: Rc>>, [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:113:36 [INFO] [stdout] | [INFO] [stdout] 113 | quack_behavior: Rc>>, [INFO] [stdout] | ^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 113 | quack_behavior: Rc>>, [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:114:34 [INFO] [stdout] | [INFO] [stdout] 114 | fly_behavior: Rc>>, [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 114 | fly_behavior: Rc>>, [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:19:48 [INFO] [stdout] | [INFO] [stdout] 19 | fn quack_behavior(&self) -> Rc>>; [INFO] [stdout] | ^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 19 | fn quack_behavior(&self) -> Rc>>; [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:24:46 [INFO] [stdout] | [INFO] [stdout] 24 | fn fly_behavior(&self) -> Rc>>; [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 24 | fn fly_behavior(&self) -> Rc>>; [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:29:50 [INFO] [stdout] | [INFO] [stdout] 29 | fn set_fly_behavior(&self, fly_behavior: Box) { [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 29 | fn set_fly_behavior(&self, fly_behavior: Box) { [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:103:48 [INFO] [stdout] | [INFO] [stdout] 103 | fn quack_behavior(&self) -> Rc>> { [INFO] [stdout] | ^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 103 | fn quack_behavior(&self) -> Rc>> { [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:106:46 [INFO] [stdout] | [INFO] [stdout] 106 | fn fly_behavior(&self) -> Rc>> { [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 106 | fn fly_behavior(&self) -> Rc>> { [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:131:48 [INFO] [stdout] | [INFO] [stdout] 131 | fn quack_behavior(&self) -> Rc>> { [INFO] [stdout] | ^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 131 | fn quack_behavior(&self) -> Rc>> { [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:134:46 [INFO] [stdout] | [INFO] [stdout] 134 | fn fly_behavior(&self) -> Rc>> { [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 134 | fn fly_behavior(&self) -> Rc>> { [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error[E0599]: no method named `remove_item` found for struct `Vec>>` in the current scope [INFO] [stdout] --> src/observer.rs:57:24 [INFO] [stdout] | [INFO] [stdout] 57 | self.observers.remove_item(&o) [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] help: there is a method `remove` with a similar name [INFO] [stdout] | [INFO] [stdout] 57 - self.observers.remove_item(&o) [INFO] [stdout] 57 + self.observers.remove(&o) [INFO] [stdout] | [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:90:73 [INFO] [stdout] | [INFO] [stdout] 90 | let fly = Rc::new(RefCell::new(Box::new(FlyWithWings {}) as Box)); [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 90 | let fly = Rc::new(RefCell::new(Box::new(FlyWithWings {}) as Box)); [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:91:68 [INFO] [stdout] | [INFO] [stdout] 91 | let quack = Rc::new(RefCell::new(Box::new(Quack {}) as Box)); [INFO] [stdout] | ^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 91 | let quack = Rc::new(RefCell::new(Box::new(Quack {}) as Box)); [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:119:69 [INFO] [stdout] | [INFO] [stdout] 119 | let fly = Rc::new(RefCell::new(Box::new(FlyNoWay {}) as Box)); [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 119 | let fly = Rc::new(RefCell::new(Box::new(FlyNoWay {}) as Box)); [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/strategy.rs:120:68 [INFO] [stdout] | [INFO] [stdout] 120 | let quack = Rc::new(RefCell::new(Box::new(Quack {}) as Box)); [INFO] [stdout] | ^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! [INFO] [stdout] = note: for more information, see [INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn` [INFO] [stdout] | [INFO] [stdout] 120 | let quack = Rc::new(RefCell::new(Box::new(Quack {}) as Box)); [INFO] [stdout] | +++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `i` [INFO] [stdout] --> src/command.rs:213:13 [INFO] [stdout] | [INFO] [stdout] 213 | for i in 0..7 { [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: `dvd` [INFO] [stdout] --> src/facade.rs:15:23 [INFO] [stdout] | [INFO] [stdout] 15 | fn set_dvd(&self, dvd: &DvdPlayer) { [INFO] [stdout] | ^^^ help: if this is intentional, prefix it with an underscore: `_dvd` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `menu_component` [INFO] [stdout] --> src/composite.rs:27:23 [INFO] [stdout] | [INFO] [stdout] 27 | fn add(&mut self, menu_component: Rc) -> Result<(), MenuComponentErr> { [INFO] [stdout] | ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_menu_component` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `menu_component` [INFO] [stdout] --> src/composite.rs:30:26 [INFO] [stdout] | [INFO] [stdout] 30 | fn remove(&mut self, menu_component: Rc) -> Result<(), MenuComponentErr> { [INFO] [stdout] | ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_menu_component` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `i` [INFO] [stdout] --> src/composite.rs:33:21 [INFO] [stdout] | [INFO] [stdout] 33 | fn child(&self, i: usize) -> Result, MenuComponentErr> { [INFO] [stdout] | ^ help: if this is intentional, prefix it with an underscore: `_i` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `v` [INFO] [stdout] --> src/composite.rs:128:29 [INFO] [stdout] | [INFO] [stdout] 128 | if let Some(ref mut v) = self.menu_components { [INFO] [stdout] | ^ help: if this is intentional, prefix it with an underscore: `_v` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `menu_component` [INFO] [stdout] --> src/composite.rs:127:26 [INFO] [stdout] | [INFO] [stdout] 127 | fn remove(&mut self, menu_component: Rc) -> Result<(), MenuComponentErr> { [INFO] [stdout] | ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_menu_component` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable does not need to be mutable [INFO] [stdout] --> src/state.rs:32:13 [INFO] [stdout] | [INFO] [stdout] 32 | let mut g = GumballMachine { [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] Some errors have detailed explanations: E0599, E0635. [INFO] [stdout] [INFO] [stdout] For more information about an error, try `rustc --explain E0599`. [INFO] [stdout] [INFO] [stderr] error: could not compile `head_first_design_patterns` (lib) due to 2 previous errors; 30 warnings emitted [INFO] running `Command { std: "docker" "inspect" "f8b81442ebf7bf830228c7c2c9680da578b81ab96bae2b753674af61cdc41a9c", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "f8b81442ebf7bf830228c7c2c9680da578b81ab96bae2b753674af61cdc41a9c", kill_on_drop: false }` [INFO] [stdout] f8b81442ebf7bf830228c7c2c9680da578b81ab96bae2b753674af61cdc41a9c