[INFO] cloning repository https://github.com/xeron56/rust_programming
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/xeron56/rust_programming" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxeron56%2Frust_programming", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxeron56%2Frust_programming'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 713c00e80573778f94cd280f73d18331d9515073
[INFO] testing xeron56/rust_programming against master#1871252fc8bb672d40787e67404e6eaae7059369 for pr-125151
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxeron56%2Frust_programming" "/workspace/builds/worker-1-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/xeron56/rust_programming on toolchain 1871252fc8bb672d40787e67404e6eaae7059369
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1871252fc8bb672d40787e67404e6eaae7059369" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/xeron56/rust_programming
[INFO] finished tweaking git repo https://github.com/xeron56/rust_programming
[INFO] tweaked toml for git repo https://github.com/xeron56/rust_programming written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/xeron56/rust_programming 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" "+1871252fc8bb672d40787e67404e6eaae7059369" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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@sha256:59a85a07ab18ca8720692f8e61effa1c651d9e2ca591e072c2b212bb91a6b8b5" "/opt/rustwide/cargo-home/bin/cargo" "+1871252fc8bb672d40787e67404e6eaae7059369" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7993001db625ef66801ff23f9f7e196900020da36ede84280f12f8b447358b6b
[INFO] running `Command { std: "docker" "start" "-a" "7993001db625ef66801ff23f9f7e196900020da36ede84280f12f8b447358b6b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7993001db625ef66801ff23f9f7e196900020da36ede84280f12f8b447358b6b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7993001db625ef66801ff23f9f7e196900020da36ede84280f12f8b447358b6b", kill_on_drop: false }`
[INFO] [stdout] 7993001db625ef66801ff23f9f7e196900020da36ede84280f12f8b447358b6b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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@sha256:59a85a07ab18ca8720692f8e61effa1c651d9e2ca591e072c2b212bb91a6b8b5" "/opt/rustwide/cargo-home/bin/cargo" "+1871252fc8bb672d40787e67404e6eaae7059369" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bb78283a068d1b5aab94c1b24da283ebb8eec1b6857661d55a315f034866c0a8
[INFO] running `Command { std: "docker" "start" "-a" "bb78283a068d1b5aab94c1b24da283ebb8eec1b6857661d55a315f034866c0a8", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust_programming v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/chapter1.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let a: i32 = 42;
[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/chapter1.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let b: u8 = 255;
[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/chapter1.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let x: f64 = 3.14;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/chapter1.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let y: f32 = 2.71828;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `is_true`
[INFO] [stdout]   --> src/chapter1.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let is_true: bool = true;
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_is_true`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `is_false`
[INFO] [stdout]   --> src/chapter1.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let is_false: bool = false;
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_is_false`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/chapter1.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let c: char = 'A';
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `emoji`
[INFO] [stdout]   --> src/chapter1.rs:39:9
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let emoji: char = '😀';
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_emoji`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]  --> src/chapter2.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let s2 = s1; // s1 is no longer valid
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/chapter3.rs:82:9
[INFO] [stdout]    |
[INFO] [stdout] 82 |     let y: Option<i32> = None;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]  --> src/chapter5.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let s2 = s1; // s1 is no longer valid
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/chapter5.rs:75:9
[INFO] [stdout]    |
[INFO] [stdout] 75 |     let mut v = vec![1, 2, 3];
[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: field `content` is never read
[INFO] [stdout]   --> src/chapter6.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 8  | struct NewsArticle {
[INFO] [stdout]    |        ----------- field in this struct
[INFO] [stdout] ...
[INFO] [stdout] 12 |     content: String,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `reply` and `retweet` are never read
[INFO] [stdout]   --> src/chapter6.rs:24:5
[INFO] [stdout]    |
[INFO] [stdout] 21 | struct Tweet {
[INFO] [stdout]    |        ----- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 24 |     reply: bool,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 25 |     retweet: bool,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `start` is never read
[INFO] [stdout]   --> src/chapter6.rs:55:5
[INFO] [stdout]    |
[INFO] [stdout] 54 | struct Range {
[INFO] [stdout]    |        ----- field in this struct
[INFO] [stdout] 55 |     start: i32,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 15 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.29s
[INFO] running `Command { std: "docker" "inspect" "bb78283a068d1b5aab94c1b24da283ebb8eec1b6857661d55a315f034866c0a8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bb78283a068d1b5aab94c1b24da283ebb8eec1b6857661d55a315f034866c0a8", kill_on_drop: false }`
[INFO] [stdout] bb78283a068d1b5aab94c1b24da283ebb8eec1b6857661d55a315f034866c0a8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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@sha256:59a85a07ab18ca8720692f8e61effa1c651d9e2ca591e072c2b212bb91a6b8b5" "/opt/rustwide/cargo-home/bin/cargo" "+1871252fc8bb672d40787e67404e6eaae7059369" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 28ed9575adcefc07458a9a3e33583b87f86cb3c958567a799a8a6f7e5fc3b566
[INFO] running `Command { std: "docker" "start" "-a" "28ed9575adcefc07458a9a3e33583b87f86cb3c958567a799a8a6f7e5fc3b566", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust_programming v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/chapter1.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let a: i32 = 42;
[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/chapter1.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let b: u8 = 255;
[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/chapter1.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let x: f64 = 3.14;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/chapter1.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let y: f32 = 2.71828;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `is_true`
[INFO] [stdout]   --> src/chapter1.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let is_true: bool = true;
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_is_true`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `is_false`
[INFO] [stdout]   --> src/chapter1.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let is_false: bool = false;
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_is_false`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/chapter1.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let c: char = 'A';
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `emoji`
[INFO] [stdout]   --> src/chapter1.rs:39:9
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let emoji: char = '😀';
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_emoji`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]  --> src/chapter2.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let s2 = s1; // s1 is no longer valid
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/chapter3.rs:82:9
[INFO] [stdout]    |
[INFO] [stdout] 82 |     let y: Option<i32> = None;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]  --> src/chapter5.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let s2 = s1; // s1 is no longer valid
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/chapter5.rs:75:9
[INFO] [stdout]    |
[INFO] [stdout] 75 |     let mut v = vec![1, 2, 3];
[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: field `content` is never read
[INFO] [stdout]   --> src/chapter6.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 8  | struct NewsArticle {
[INFO] [stdout]    |        ----------- field in this struct
[INFO] [stdout] ...
[INFO] [stdout] 12 |     content: String,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `reply` and `retweet` are never read
[INFO] [stdout]   --> src/chapter6.rs:24:5
[INFO] [stdout]    |
[INFO] [stdout] 21 | struct Tweet {
[INFO] [stdout]    |        ----- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 24 |     reply: bool,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 25 |     retweet: bool,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `start` is never read
[INFO] [stdout]   --> src/chapter6.rs:55:5
[INFO] [stdout]    |
[INFO] [stdout] 54 | struct Range {
[INFO] [stdout]    |        ----- field in this struct
[INFO] [stdout] 55 |     start: i32,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 15 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.18s
[INFO] running `Command { std: "docker" "inspect" "28ed9575adcefc07458a9a3e33583b87f86cb3c958567a799a8a6f7e5fc3b566", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "28ed9575adcefc07458a9a3e33583b87f86cb3c958567a799a8a6f7e5fc3b566", kill_on_drop: false }`
[INFO] [stdout] 28ed9575adcefc07458a9a3e33583b87f86cb3c958567a799a8a6f7e5fc3b566
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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@sha256:59a85a07ab18ca8720692f8e61effa1c651d9e2ca591e072c2b212bb91a6b8b5" "/opt/rustwide/cargo-home/bin/cargo" "+1871252fc8bb672d40787e67404e6eaae7059369" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] fb8551f787fd292fe52863c9c00a164d57eb04fb6d910c0e713182288cff2ff8
[INFO] running `Command { std: "docker" "start" "-a" "fb8551f787fd292fe52863c9c00a164d57eb04fb6d910c0e713182288cff2ff8", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `a`
[INFO] [stderr]   --> src/chapter1.rs:26:9
[INFO] [stderr]    |
[INFO] [stderr] 26 |     let a: i32 = 42;
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `b`
[INFO] [stderr]   --> src/chapter1.rs:27:9
[INFO] [stderr]    |
[INFO] [stderr] 27 |     let b: u8 = 255;
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/chapter1.rs:30:9
[INFO] [stderr]    |
[INFO] [stderr] 30 |     let x: f64 = 3.14;
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `y`
[INFO] [stderr]   --> src/chapter1.rs:31:9
[INFO] [stderr]    |
[INFO] [stderr] 31 |     let y: f32 = 2.71828;
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `is_true`
[INFO] [stderr]   --> src/chapter1.rs:34:9
[INFO] [stderr]    |
[INFO] [stderr] 34 |     let is_true: bool = true;
[INFO] [stderr]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_is_true`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `is_false`
[INFO] [stderr]   --> src/chapter1.rs:35:9
[INFO] [stderr]    |
[INFO] [stderr] 35 |     let is_false: bool = false;
[INFO] [stderr]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_is_false`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `c`
[INFO] [stderr]   --> src/chapter1.rs:38:9
[INFO] [stderr]    |
[INFO] [stderr] 38 |     let c: char = 'A';
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `emoji`
[INFO] [stderr]   --> src/chapter1.rs:39:9
[INFO] [stderr]    |
[INFO] [stderr] 39 |     let emoji: char = '😀';
[INFO] [stderr]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_emoji`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s2`
[INFO] [stderr]  --> src/chapter2.rs:7:9
[INFO] [stderr]   |
[INFO] [stderr] 7 |     let s2 = s1; // s1 is no longer valid
[INFO] [stderr]   |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `y`
[INFO] [stderr]   --> src/chapter3.rs:82:9
[INFO] [stderr]    |
[INFO] [stderr] 82 |     let y: Option<i32> = None;
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s2`
[INFO] [stderr]  --> src/chapter5.rs:7:9
[INFO] [stderr]   |
[INFO] [stderr] 7 |     let s2 = s1; // s1 is no longer valid
[INFO] [stderr]   |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/chapter5.rs:75:9
[INFO] [stderr]    |
[INFO] [stderr] 75 |     let mut v = vec![1, 2, 3];
[INFO] [stderr]    |         ----^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field `content` is never read
[INFO] [stderr]   --> src/chapter6.rs:12:5
[INFO] [stderr]    |
[INFO] [stderr] 8  | struct NewsArticle {
[INFO] [stderr]    |        ----------- field in this struct
[INFO] [stderr] ...
[INFO] [stderr] 12 |     content: String,
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: fields `reply` and `retweet` are never read
[INFO] [stderr]   --> src/chapter6.rs:24:5
[INFO] [stderr]    |
[INFO] [stderr] 21 | struct Tweet {
[INFO] [stderr]    |        ----- fields in this struct
[INFO] [stderr] ...
[INFO] [stderr] 24 |     reply: bool,
[INFO] [stderr]    |     ^^^^^
[INFO] [stderr] 25 |     retweet: bool,
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field `start` is never read
[INFO] [stderr]   --> src/chapter6.rs:55:5
[INFO] [stderr]    |
[INFO] [stderr] 54 | struct Range {
[INFO] [stderr]    |        ----- field in this struct
[INFO] [stderr] 55 |     start: i32,
[INFO] [stderr]    |     ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: `rust_programming` (bin "rust_programming" test) generated 15 warnings (run `cargo fix --bin "rust_programming" --tests` to apply 1 suggestion)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.00s
[INFO] [stderr]      Running unittests src/main.rs (/opt/rustwide/target/debug/deps/rust_programming-21a2bbe77e2a590b)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "fb8551f787fd292fe52863c9c00a164d57eb04fb6d910c0e713182288cff2ff8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fb8551f787fd292fe52863c9c00a164d57eb04fb6d910c0e713182288cff2ff8", kill_on_drop: false }`
[INFO] [stdout] fb8551f787fd292fe52863c9c00a164d57eb04fb6d910c0e713182288cff2ff8
