[INFO] cloning repository https://github.com/AndrewCushing/Rust-The_book
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/AndrewCushing/Rust-The_book" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAndrewCushing%2FRust-The_book", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAndrewCushing%2FRust-The_book'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 13bdca24b116c7c3ce4fa603fbae957e33965255
[INFO] checking AndrewCushing/Rust-The_book/13bdca24b116c7c3ce4fa603fbae957e33965255 against master#f609b7e0586f81fefb3523e3e17adf779ac416be for pr-129466-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAndrewCushing%2FRust-The_book" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/AndrewCushing/Rust-The_book on toolchain f609b7e0586f81fefb3523e3e17adf779ac416be
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/AndrewCushing/Rust-The_book
[INFO] finished tweaking git repo https://github.com/AndrewCushing/Rust-The_book
[INFO] tweaked toml for git repo https://github.com/AndrewCushing/Rust-The_book written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/AndrewCushing/Rust-The_book 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" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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:ceb6ea022f8a89cebbe621bb4987e73a935bd40dfbb726f832cfff4742a5b95a" "/opt/rustwide/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6e2b0215d598f6180db32f9b0087b7258ba2c8668031ef64d90b91af858a3a89
[INFO] running `Command { std: "docker" "start" "-a" "6e2b0215d598f6180db32f9b0087b7258ba2c8668031ef64d90b91af858a3a89", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6e2b0215d598f6180db32f9b0087b7258ba2c8668031ef64d90b91af858a3a89", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6e2b0215d598f6180db32f9b0087b7258ba2c8668031ef64d90b91af858a3a89", kill_on_drop: false }`
[INFO] [stdout] 6e2b0215d598f6180db32f9b0087b7258ba2c8668031ef64d90b91af858a3a89
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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:ceb6ea022f8a89cebbe621bb4987e73a935bd40dfbb726f832cfff4742a5b95a" "/opt/rustwide/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f9f5337fab7cc07570ca72a3f015ce09759fc75363d59c235b1023c3e1604f15
[INFO] running `Command { std: "docker" "start" "-a" "f9f5337fab7cc07570ca72a3f015ce09759fc75363d59c235b1023c3e1604f15", kill_on_drop: false }`
[INFO] [stderr]     Checking common_programming_concepts v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0583]: file not found for module `ownership`
[INFO] [stdout]  --> src/main.rs:7:1
[INFO] [stdout]   |
[INFO] [stdout] 7 | mod ownership;
[INFO] [stdout]   | ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: to create the module `ownership`, create file "src/ownership.rs" or "src/ownership/mod.rs"
[INFO] [stdout]   = note: if there is a `mod ownership` elsewhere in the crate already, import it with `use crate::...` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0583]: file not found for module `ownership`
[INFO] [stdout]  --> src/main.rs:7:1
[INFO] [stdout]   |
[INFO] [stdout] 7 | mod ownership;
[INFO] [stdout]   | ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: to create the module `ownership`, create file "src/ownership.rs" or "src/ownership/mod.rs"
[INFO] [stdout]   = note: if there is a `mod ownership` elsewhere in the crate already, import it with `use crate::...` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cmp::max`
[INFO] [stdout]  --> src/challenges/chapter_8/mean_median_mode.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::cmp::max;
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::borrow::Borrow`
[INFO] [stdout]  --> src/challenges/chapter_8/mean_median_mode.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type `company` should have an upper camel case name
[INFO] [stdout]  --> src/challenges/chapter_8/staff.rs:7:12
[INFO] [stdout]   |
[INFO] [stdout] 7 | pub struct company {
[INFO] [stdout]   |            ^^^^^^^ help: convert the identifier to upper camel case (notice the capitalization): `Company`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(non_camel_case_types)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cmp::max`
[INFO] [stdout]  --> src/challenges/chapter_8/mean_median_mode.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::cmp::max;
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::borrow::Borrow`
[INFO] [stdout]  --> src/challenges/chapter_8/mean_median_mode.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type `company` should have an upper camel case name
[INFO] [stdout]  --> src/challenges/chapter_8/staff.rs:7:12
[INFO] [stdout]   |
[INFO] [stdout] 7 | pub struct company {
[INFO] [stdout]   |            ^^^^^^^ help: convert the identifier to upper camel case (notice the capitalization): `Company`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(non_camel_case_types)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]  --> src/data_types.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let a: i8 = 0; // i for integer
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]  --> src/data_types.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let a: i8 = 0; // i for integer
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]  --> src/data_types.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let b: u8 = 0; // u for unsigned integer
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]  --> src/data_types.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let b: u8 = 0; // u for unsigned integer
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]  --> src/data_types.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let c: i16 = 0;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]  --> src/data_types.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let c: i16 = 0;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `d`
[INFO] [stdout]  --> src/data_types.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let d: u16 = 0;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_d`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `d`
[INFO] [stdout]  --> src/data_types.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let d: u16 = 0;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_d`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `e`
[INFO] [stdout]  --> src/data_types.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let e: i32 = 0;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_e`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `e`
[INFO] [stdout]  --> src/data_types.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let e: i32 = 0;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_e`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]  --> src/data_types.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let f: u32 = 0;
[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/data_types.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let f: u32 = 0;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `g`
[INFO] [stdout]  --> src/data_types.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let g: i64 = 0;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_g`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `g`
[INFO] [stdout]  --> src/data_types.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let g: i64 = 0;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_g`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `h`
[INFO] [stdout]   --> src/data_types.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let h: u64 = 0;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_h`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `h`
[INFO] [stdout]   --> src/data_types.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let h: u64 = 0;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_h`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `bob`
[INFO] [stdout]   --> src/data_types.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let bob = 0xfffffffi64; // Type suffice and 0x prefix (meaning this is hex)
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_bob`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `bob`
[INFO] [stdout]   --> src/data_types.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let bob = 0xfffffffi64; // Type suffice and 0x prefix (meaning this is hex)
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_bob`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/data_types.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let i:i64 = 100_000_000;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/data_types.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let i:i64 = 100_000_000;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/data_types.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let a: [i32; 4] = [36, 45, 87, 98];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/data_types.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let a: [i32; 4] = [36, 45, 87, 98];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/data_types.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let b: [i64; 3] = [999; 3];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/data_types.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let c = [999i64, 999i64, 999i64];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/data_types.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let b: [i64; 3] = [999; 3];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]  --> src/variables_and_mutability.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let x = 5; // Variables are immutable by default
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/data_types.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let c = [999i64, 999i64, 999i64];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `y` is assigned to, but never used
[INFO] [stdout]  --> src/variables_and_mutability.rs:6:13
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let mut y = 4; // This is how to make a mutable variable
[INFO] [stdout]   |             ^
[INFO] [stdout]   |
[INFO] [stdout]   = note: consider using `_y` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]  --> src/variables_and_mutability.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let x = 5; // Variables are immutable by default
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `y` is never read
[INFO] [stdout]  --> src/variables_and_mutability.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 |     y = 9; // Now this is perfectly valid
[INFO] [stdout]   |     ^
[INFO] [stdout]   |
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[INFO] [stdout]   = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/variables_and_mutability.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let a = 7;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/variables_and_mutability.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let a = 9; // We say this variable 'shadows' the original one. Whenever we access a from now on, we'll get this value
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/variables_and_mutability.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let a = "blah"; // We can even use shadowing to make a have a different type, just to make things more confusing
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `y` is assigned to, but never used
[INFO] [stdout]  --> src/variables_and_mutability.rs:6:13
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let mut y = 4; // This is how to make a mutable variable
[INFO] [stdout]   |             ^
[INFO] [stdout]   |
[INFO] [stdout]   = note: consider using `_y` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `y` is never read
[INFO] [stdout]  --> src/variables_and_mutability.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 |     y = 9; // Now this is perfectly valid
[INFO] [stdout]   |     ^
[INFO] [stdout]   |
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[INFO] [stdout]   = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/variables_and_mutability.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let a = 7;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/variables_and_mutability.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let a = 9; // We say this variable 'shadows' the original one. Whenever we access a from now on, we'll get this value
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/variables_and_mutability.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let a = "blah"; // We can even use shadowing to make a have a different type, just to make things more confusing
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `default`
[INFO] [stdout]   --> src/challenges/chapter_3/twelve_days_of_christmas.rs:39:9
[INFO] [stdout]    |
[INFO] [stdout] 39 |         default => "blah".to_string()
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_default`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `default`
[INFO] [stdout]   --> src/challenges/chapter_3/twelve_days_of_christmas.rs:39:9
[INFO] [stdout]    |
[INFO] [stdout] 39 |         default => "blah".to_string()
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_default`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `median` is never read
[INFO] [stdout]   --> src/challenges/chapter_8/mean_median_mode.rs:14:13
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut median: f32 = 0.0;
[INFO] [stdout]    |             ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `median` is never read
[INFO] [stdout]   --> src/challenges/chapter_8/mean_median_mode.rs:14:13
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut median: f32 = 0.0;
[INFO] [stdout]    |             ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `origin`
[INFO] [stdout]   --> src/structs_stuff.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let origin = Point(0, 0, 0);
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_origin`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `my_point`
[INFO] [stdout]   --> src/structs_stuff.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let my_point = Point(4, 5, 6);
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_my_point`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integers`
[INFO] [stdout]  --> src/collections.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let integers: Vec<i32> = Vec::new();
[INFO] [stdout]   |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integers`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `v_first` is never read
[INFO] [stdout]   --> src/collections.rs:14:13
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut v_first = v[0]; // Temporary mutable borrow but essentially a shallow copy, as v_first will be on the stack
[INFO] [stdout]    |             ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/collections.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let mut v = vec![1, 2, 3, 4, 5];
[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: variable does not need to be mutable
[INFO] [stdout]   --> src/collections.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let mut y_first = &mut y[0]; // Mutable borrow
[INFO] [stdout]    |         ----^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `origin`
[INFO] [stdout]   --> src/structs_stuff.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let origin = Point(0, 0, 0);
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_origin`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `my_point`
[INFO] [stdout]   --> src/structs_stuff.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let my_point = Point(4, 5, 6);
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_my_point`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/string_stuff.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     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/string_stuff.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     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: `hello`
[INFO] [stdout]   --> src/string_stuff.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     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: `integers`
[INFO] [stdout]  --> src/collections.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let integers: Vec<i32> = Vec::new();
[INFO] [stdout]   |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integers`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/string_stuff.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     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: value assigned to `v_first` is never read
[INFO] [stdout]   --> src/collections.rs:14:13
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut v_first = v[0]; // Temporary mutable borrow but essentially a shallow copy, as v_first will be on the stack
[INFO] [stdout]    |             ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/string_stuff.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     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/string_stuff.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     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/string_stuff.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     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/string_stuff.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     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/string_stuff.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     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/string_stuff.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     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/string_stuff.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     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/string_stuff.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     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/string_stuff.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     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/collections.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let mut v = vec![1, 2, 3, 4, 5];
[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: variable does not need to be mutable
[INFO] [stdout]   --> src/collections.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let mut y_first = &mut y[0]; // Mutable borrow
[INFO] [stdout]    |         ----^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]  --> src/errors_stuff.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let f = match f {
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/string_stuff.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     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/string_stuff.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     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: `hello`
[INFO] [stdout]   --> src/string_stuff.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     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/string_stuff.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     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/string_stuff.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     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/string_stuff.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     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/string_stuff.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     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/string_stuff.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     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/string_stuff.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     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: `something`
[INFO] [stdout]   --> src/traits_stuff.rs:31:15
[INFO] [stdout]    |
[INFO] [stdout] 31 | fn some_func (something: &impl Summary) {
[INFO] [stdout]    |               ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_something`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/string_stuff.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     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/string_stuff.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     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/string_stuff.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     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/string_stuff.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     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: unused variable: `f`
[INFO] [stdout]  --> src/errors_stuff.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let f = match f {
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error; 45 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0583`.
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `something`
[INFO] [stdout]   --> src/traits_stuff.rs:31:15
[INFO] [stdout]    |
[INFO] [stdout] 31 | fn some_func (something: &impl Summary) {
[INFO] [stdout]    |               ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_something`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error; 45 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0583`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `common_programming_concepts` (bin "common_programming_concepts") due to 2 previous errors; 45 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `common_programming_concepts` (bin "common_programming_concepts" test) due to 2 previous errors; 45 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "f9f5337fab7cc07570ca72a3f015ce09759fc75363d59c235b1023c3e1604f15", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f9f5337fab7cc07570ca72a3f015ce09759fc75363d59c235b1023c3e1604f15", kill_on_drop: false }`
[INFO] [stdout] f9f5337fab7cc07570ca72a3f015ce09759fc75363d59c235b1023c3e1604f15