[INFO] cloning repository https://github.com/tyrellcurry/rustbook
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tyrellcurry/rustbook" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftyrellcurry%2Frustbook", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftyrellcurry%2Frustbook'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 2d88b801be30142c86a780629de6a7f45ce109da
[INFO] checking tyrellcurry/rustbook against try#50d7e48beb74b48bd17c3749bfb73843c9ae0166 for pr-151102
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftyrellcurry%2Frustbook" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/tyrellcurry/rustbook
[INFO] finished tweaking git repo https://github.com/tyrellcurry/rustbook
[INFO] tweaked toml for git repo https://github.com/tyrellcurry/rustbook written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/tyrellcurry/rustbook on toolchain 50d7e48beb74b48bd17c3749bfb73843c9ae0166
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+50d7e48beb74b48bd17c3749bfb73843c9ae0166" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/tyrellcurry/rustbook 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" "+50d7e48beb74b48bd17c3749bfb73843c9ae0166" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[INFO] checking tyrellcurry/rustbook against try#50d7e48beb74b48bd17c3749bfb73843c9ae0166 for pr-151102
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftyrellcurry%2Frustbook" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/tyrellcurry/rustbook
[INFO] finished tweaking git repo https://github.com/tyrellcurry/rustbook
[INFO] tweaked toml for git repo https://github.com/tyrellcurry/rustbook written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/tyrellcurry/rustbook on toolchain 50d7e48beb74b48bd17c3749bfb73843c9ae0166
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+50d7e48beb74b48bd17c3749bfb73843c9ae0166" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/tyrellcurry/rustbook 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" "+50d7e48beb74b48bd17c3749bfb73843c9ae0166" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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@sha256:98afbf2d16093dec2546ff8915fddc74e65664aa03fc460b3712b1c2c54a33e4" "/opt/rustwide/cargo-home/bin/cargo" "+50d7e48beb74b48bd17c3749bfb73843c9ae0166" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 552e8e36c1fe6363a3a6e043c318bef288279d5cec9d48228c36a85d80ac93a3
[INFO] running `Command { std: "docker" "start" "-a" "552e8e36c1fe6363a3a6e043c318bef288279d5cec9d48228c36a85d80ac93a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "552e8e36c1fe6363a3a6e043c318bef288279d5cec9d48228c36a85d80ac93a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "552e8e36c1fe6363a3a6e043c318bef288279d5cec9d48228c36a85d80ac93a3", kill_on_drop: false }`
[INFO] [stdout] 552e8e36c1fe6363a3a6e043c318bef288279d5cec9d48228c36a85d80ac93a3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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@sha256:98afbf2d16093dec2546ff8915fddc74e65664aa03fc460b3712b1c2c54a33e4" "/opt/rustwide/cargo-home/bin/cargo" "+50d7e48beb74b48bd17c3749bfb73843c9ae0166" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6166d271de90b76356a01de292823625951fb558f6820376f3b34228326becbc
[INFO] running `Command { std: "docker" "start" "-a" "6166d271de90b76356a01de292823625951fb558f6820376f3b34228326becbc", kill_on_drop: false }`
[INFO] [stderr]     Checking rand v0.9.2
[INFO] [stderr]     Checking rust_book v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0532]: expected unit struct, unit variant or constant, found tuple variant `Coin::Quarter`
[INFO] [stdout]   --> src/chapters/enums_and_pattern_matching/control_flow.rs:26:13
[INFO] [stdout]    |
[INFO] [stdout] 12 |     Quarter(UsState),
[INFO] [stdout]    |     ---------------- `Coin::Quarter` defined here
[INFO] [stdout] ...
[INFO] [stdout] 26 |             Coin::Quarter => 25,
[INFO] [stdout]    |             ^^^^^^^^^^^^^ help: use the tuple variant pattern syntax instead: `Coin::Quarter(_)`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0532]: expected unit struct, unit variant or constant, found tuple variant `Coin::Quarter`
[INFO] [stdout]   --> src/chapters/enums_and_pattern_matching/control_flow.rs:26:13
[INFO] [stdout]    |
[INFO] [stdout] 12 |     Quarter(UsState),
[INFO] [stdout]    |     ---------------- `Coin::Quarter` defined here
[INFO] [stdout] ...
[INFO] [stdout] 26 |             Coin::Quarter => 25,
[INFO] [stdout]    |             ^^^^^^^^^^^^^ help: use the tuple variant pattern syntax instead: `Coin::Quarter(_)`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::array`
[INFO] [stdout]  --> src/chapters/common_programming_concepts/control_flow.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::array;
[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::array`
[INFO] [stdout]  --> src/chapters/common_programming_concepts/control_flow.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::array;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated function `rand::thread_rng`: Renamed to `rng`
[INFO] [stdout]  --> src/chapters/guessing_game/guessing_game.rs:9:31
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let secret_number = rand::thread_rng().gen_range(1..=100);
[INFO] [stdout]   |                               ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated function `rand::thread_rng`: Renamed to `rng`
[INFO] [stdout]  --> src/chapters/guessing_game/guessing_game.rs:9:31
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let secret_number = rand::thread_rng().gen_range(1..=100);
[INFO] [stdout]   |                               ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]   --> src/chapters/common_programming_concepts/control_flow.rs:29:5
[INFO] [stdout]    |
[INFO] [stdout] 21 |         return;
[INFO] [stdout]    |         ------ any code following this expression is unreachable
[INFO] [stdout] ...
[INFO] [stdout] 29 |     let condition = true;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^ unreachable statement
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]   --> src/chapters/common_programming_concepts/control_flow.rs:29:5
[INFO] [stdout]    |
[INFO] [stdout] 21 |         return;
[INFO] [stdout]    |         ------ any code following this expression is unreachable
[INFO] [stdout] ...
[INFO] [stdout] 29 |     let condition = true;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^ unreachable statement
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated method `rand::Rng::gen_range`: Renamed to `random_range`
[INFO] [stdout]  --> src/chapters/guessing_game/guessing_game.rs:9:44
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let secret_number = rand::thread_rng().gen_range(1..=100);
[INFO] [stdout]   |                                            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated method `rand::Rng::gen_range`: Renamed to `random_range`
[INFO] [stdout]  --> src/chapters/guessing_game/guessing_game.rs:9:44
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let secret_number = rand::thread_rng().gen_range(1..=100);
[INFO] [stdout]   |                                            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `guess`
[INFO] [stdout]  --> src/chapters/common_programming_concepts/data_types.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let guess: u32 = "42".parse().expect("Not a number!"); // 42 (type u32)
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_guess`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `signedInt`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let signedInt: i32 = -69;
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_signedInt`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `unsignedInt`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let unsignedInt: u32 = 69;
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_unsignedInt`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let x = 2.0; // default type is f64
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |     let x: f32 = 3.0;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `product`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let product = 4 * 30;
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_product`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let t = true;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let f: bool = false;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `guess`
[INFO] [stdout]  --> src/chapters/common_programming_concepts/data_types.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let guess: u32 = "42".parse().expect("Not a number!"); // 42 (type u32)
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_guess`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:36:9
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let c = 'c';
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `signedInt`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let signedInt: i32 = -69;
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_signedInt`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let z: char = 'z';
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `unsignedInt`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let unsignedInt: u32 = 69;
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_unsignedInt`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let x = 2.0; // default type is f64
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `tup`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:44:9
[INFO] [stdout]    |
[INFO] [stdout] 44 |     let tup: (i32, f64, u8) = (500, 6.4, 1);
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_tup`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |     let x: f32 = 3.0;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `tup`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:45:9
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let tup = (500, 6.4, 1);
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_tup`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `product`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let product = 4 * 30;
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_product`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let c = tup.0;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `string`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let string = tup.1;
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `num`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:55:9
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let num = tup.2;
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_num`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `arr`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:60:9
[INFO] [stdout]    |
[INFO] [stdout] 60 |     let arr = [1, 2, 3, 4, 5];
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_arr`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `str`
[INFO] [stdout]  --> src/chapters/common_programming_concepts/functions.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let str = defined_below_func();
[INFO] [stdout]   |         ^^^ help: if this is intentional, prefix it with an underscore: `_str`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/functions.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let y = "y";
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/functions.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let y =
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let t = true;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let f: bool = false;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:36:9
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let c = 'c';
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let z: char = 'z';
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `tup`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:44:9
[INFO] [stdout]    |
[INFO] [stdout] 44 |     let tup: (i32, f64, u8) = (500, 6.4, 1);
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_tup`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `tup`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:45:9
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let tup = (500, 6.4, 1);
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_tup`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let c = tup.0;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `string`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let string = tup.1;
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `num`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:55:9
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let num = tup.2;
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_num`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `arr`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/data_types.rs:60:9
[INFO] [stdout]    |
[INFO] [stdout] 60 |     let arr = [1, 2, 3, 4, 5];
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_arr`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `str`
[INFO] [stdout]  --> src/chapters/common_programming_concepts/functions.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let str = defined_below_func();
[INFO] [stdout]   |         ^^^ help: if this is intentional, prefix it with an underscore: `_str`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/functions.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let y = "y";
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/functions.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let y =
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/chapters/common_programming_concepts/variables_and_mutability.rs:42:13
[INFO] [stdout]    |
[INFO] [stdout] 42 |         let mut spaces = "   ";
[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] warning: unused variable: `spaces`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/variables_and_mutability.rs:39:13
[INFO] [stdout]    |
[INFO] [stdout] 39 |         let spaces = spaces.len();
[INFO] [stdout]    |             ^^^^^^ help: if this is intentional, prefix it with an underscore: `_spaces`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `spaces`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/variables_and_mutability.rs:42:13
[INFO] [stdout]    |
[INFO] [stdout] 42 |         let mut spaces = "   ";
[INFO] [stdout]    |             ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_spaces`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/chapters/common_programming_concepts/variables_and_mutability.rs:42:13
[INFO] [stdout]    |
[INFO] [stdout] 42 |         let mut spaces = "   ";
[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] warning: unused variable: `spaces`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/variables_and_mutability.rs:39:13
[INFO] [stdout]    |
[INFO] [stdout] 39 |         let spaces = spaces.len();
[INFO] [stdout]    |             ^^^^^^ help: if this is intentional, prefix it with an underscore: `_spaces`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `spaces`
[INFO] [stdout]   --> src/chapters/common_programming_concepts/variables_and_mutability.rs:42:13
[INFO] [stdout]    |
[INFO] [stdout] 42 |         let mut spaces = "   ";
[INFO] [stdout]    |             ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_spaces`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0532`.
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0532`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_book` (bin "rust_book") due to 1 previous error; 26 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `rust_book` (bin "rust_book" test) due to 1 previous error; 26 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "6166d271de90b76356a01de292823625951fb558f6820376f3b34228326becbc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6166d271de90b76356a01de292823625951fb558f6820376f3b34228326becbc", kill_on_drop: false }`
[INFO] [stdout] 6166d271de90b76356a01de292823625951fb558f6820376f3b34228326becbc
