[INFO] cloning repository https://github.com/TerraDev64/rust_book
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/TerraDev64/rust_book" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FTerraDev64%2Frust_book", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FTerraDev64%2Frust_book'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3f92cd51ffe8657f18fbff1e86ef0a758053c276
[INFO] testing TerraDev64/rust_book against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FTerraDev64%2Frust_book" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/TerraDev64/rust_book on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/TerraDev64/rust_book
[INFO] finished tweaking git repo https://github.com/TerraDev64/rust_book
[INFO] tweaked toml for git repo https://github.com/TerraDev64/rust_book written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/TerraDev64/rust_book already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 24c672fe2db1e21138c5c7505673171f4db221d26ec89cf572de0e53ded85dbb
[INFO] running `Command { std: "docker" "start" "-a" "24c672fe2db1e21138c5c7505673171f4db221d26ec89cf572de0e53ded85dbb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "24c672fe2db1e21138c5c7505673171f4db221d26ec89cf572de0e53ded85dbb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "24c672fe2db1e21138c5c7505673171f4db221d26ec89cf572de0e53ded85dbb", kill_on_drop: false }`
[INFO] [stdout] 24c672fe2db1e21138c5c7505673171f4db221d26ec89cf572de0e53ded85dbb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6e5d5f978c71d3c2b80d541ad9d116f8f8303d65941b182c8a6dc408c7454e8b
[INFO] running `Command { std: "docker" "start" "-a" "6e5d5f978c71d3c2b80d541ad9d116f8f8303d65941b182c8a6dc408c7454e8b", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust_book v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/main.rs:15:13
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let r1 = &mut s;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/main.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let r2 = &mut s;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/main.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let r2 = &s; //Works
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `guess`
[INFO] [stdout]   --> src/main.rs:48:9
[INFO] [stdout]    |
[INFO] [stdout] 48 |     let guess: u32 = "42".parse().expect("Not a number!");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_guess`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/main.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let x = 2.0;
[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/main.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let y: f32 = 3.0;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sum`
[INFO] [stdout]   --> src/main.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let sum = 5 + 10;
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_sum`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `difference`
[INFO] [stdout]   --> src/main.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let difference = 95.5 - 4.3;
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_difference`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `product`
[INFO] [stdout]   --> src/main.rs:60:9
[INFO] [stdout]    |
[INFO] [stdout] 60 |     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: `quotient`
[INFO] [stdout]   --> src/main.rs:63:9
[INFO] [stdout]    |
[INFO] [stdout] 63 |     let quotient = 56.7 / 32.2;
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_quotient`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `remainder`
[INFO] [stdout]   --> src/main.rs:66:9
[INFO] [stdout]    |
[INFO] [stdout] 66 |     let remainder = 43 % 5;
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_remainder`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/main.rs:68:9
[INFO] [stdout]    |
[INFO] [stdout] 68 |     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/main.rs:69:9
[INFO] [stdout]    |
[INFO] [stdout] 69 |     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/main.rs:71:9
[INFO] [stdout]    |
[INFO] [stdout] 71 |     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/main.rs:72:9
[INFO] [stdout]    |
[INFO] [stdout] 72 |     let z = 'z';
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `heart_eyed_cat`
[INFO] [stdout]   --> src/main.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let heart_eyed_cat = '😻';
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_heart_eyed_cat`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/main.rs:77:10
[INFO] [stdout]    |
[INFO] [stdout] 77 |     let (x,y,z)  = tup;
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/main.rs:77:14
[INFO] [stdout]    |
[INFO] [stdout] 77 |     let (x,y,z)  = tup;
[INFO] [stdout]    |              ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `five_hundred`
[INFO] [stdout]   --> src/main.rs:82:9
[INFO] [stdout]    |
[INFO] [stdout] 82 |     let five_hundred = x.0;
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_five_hundred`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six_point_four`
[INFO] [stdout]   --> src/main.rs:83:9
[INFO] [stdout]    |
[INFO] [stdout] 83 |     let six_point_four = x.1;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_six_point_four`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `one`
[INFO] [stdout]   --> src/main.rs:84:9
[INFO] [stdout]    |
[INFO] [stdout] 84 |     let one = x.2;
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_one`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `spaces`
[INFO] [stdout]   --> src/main.rs:94:9
[INFO] [stdout]    |
[INFO] [stdout] 94 |     let spaces = spaces.len();
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_spaces`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `ownership`
[INFO] [stdout]   --> src/main.rs:29:4
[INFO] [stdout]    |
[INFO] [stdout] 29 | fn ownership() {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `data_types`
[INFO] [stdout]   --> src/main.rs:47:4
[INFO] [stdout]    |
[INFO] [stdout] 47 | fn data_types() {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `shadowing`
[INFO] [stdout]   --> src/main.rs:87:4
[INFO] [stdout]    |
[INFO] [stdout] 87 | fn shadowing() {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `mutable_variables`
[INFO] [stdout]   --> src/main.rs:97:4
[INFO] [stdout]    |
[INFO] [stdout] 97 | fn mutable_variables() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 26 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.30s
[INFO] running `Command { std: "docker" "inspect" "6e5d5f978c71d3c2b80d541ad9d116f8f8303d65941b182c8a6dc408c7454e8b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6e5d5f978c71d3c2b80d541ad9d116f8f8303d65941b182c8a6dc408c7454e8b", kill_on_drop: false }`
[INFO] [stdout] 6e5d5f978c71d3c2b80d541ad9d116f8f8303d65941b182c8a6dc408c7454e8b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] cee5c95ef4b646dc41f7ec3938ca1acda05dffb02d88692fed30cf009b02ff99
[INFO] running `Command { std: "docker" "start" "-a" "cee5c95ef4b646dc41f7ec3938ca1acda05dffb02d88692fed30cf009b02ff99", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust_book v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/main.rs:15:13
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let r1 = &mut s;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/main.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let r2 = &mut s;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/main.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let r2 = &s; //Works
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `guess`
[INFO] [stdout]   --> src/main.rs:48:9
[INFO] [stdout]    |
[INFO] [stdout] 48 |     let guess: u32 = "42".parse().expect("Not a number!");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_guess`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/main.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let x = 2.0;
[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/main.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let y: f32 = 3.0;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sum`
[INFO] [stdout]   --> src/main.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let sum = 5 + 10;
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_sum`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `difference`
[INFO] [stdout]   --> src/main.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let difference = 95.5 - 4.3;
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_difference`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `product`
[INFO] [stdout]   --> src/main.rs:60:9
[INFO] [stdout]    |
[INFO] [stdout] 60 |     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: `quotient`
[INFO] [stdout]   --> src/main.rs:63:9
[INFO] [stdout]    |
[INFO] [stdout] 63 |     let quotient = 56.7 / 32.2;
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_quotient`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `remainder`
[INFO] [stdout]   --> src/main.rs:66:9
[INFO] [stdout]    |
[INFO] [stdout] 66 |     let remainder = 43 % 5;
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_remainder`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/main.rs:68:9
[INFO] [stdout]    |
[INFO] [stdout] 68 |     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/main.rs:69:9
[INFO] [stdout]    |
[INFO] [stdout] 69 |     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/main.rs:71:9
[INFO] [stdout]    |
[INFO] [stdout] 71 |     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/main.rs:72:9
[INFO] [stdout]    |
[INFO] [stdout] 72 |     let z = 'z';
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `heart_eyed_cat`
[INFO] [stdout]   --> src/main.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let heart_eyed_cat = '😻';
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_heart_eyed_cat`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/main.rs:77:10
[INFO] [stdout]    |
[INFO] [stdout] 77 |     let (x,y,z)  = tup;
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/main.rs:77:14
[INFO] [stdout]    |
[INFO] [stdout] 77 |     let (x,y,z)  = tup;
[INFO] [stdout]    |              ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `five_hundred`
[INFO] [stdout]   --> src/main.rs:82:9
[INFO] [stdout]    |
[INFO] [stdout] 82 |     let five_hundred = x.0;
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_five_hundred`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six_point_four`
[INFO] [stdout]   --> src/main.rs:83:9
[INFO] [stdout]    |
[INFO] [stdout] 83 |     let six_point_four = x.1;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_six_point_four`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `one`
[INFO] [stdout]   --> src/main.rs:84:9
[INFO] [stdout]    |
[INFO] [stdout] 84 |     let one = x.2;
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_one`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `spaces`
[INFO] [stdout]   --> src/main.rs:94:9
[INFO] [stdout]    |
[INFO] [stdout] 94 |     let spaces = spaces.len();
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_spaces`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `ownership`
[INFO] [stdout]   --> src/main.rs:29:4
[INFO] [stdout]    |
[INFO] [stdout] 29 | fn ownership() {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `data_types`
[INFO] [stdout]   --> src/main.rs:47:4
[INFO] [stdout]    |
[INFO] [stdout] 47 | fn data_types() {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `shadowing`
[INFO] [stdout]   --> src/main.rs:87:4
[INFO] [stdout]    |
[INFO] [stdout] 87 | fn shadowing() {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `mutable_variables`
[INFO] [stdout]   --> src/main.rs:97:4
[INFO] [stdout]    |
[INFO] [stdout] 97 | fn mutable_variables() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 26 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.31s
[INFO] running `Command { std: "docker" "inspect" "cee5c95ef4b646dc41f7ec3938ca1acda05dffb02d88692fed30cf009b02ff99", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cee5c95ef4b646dc41f7ec3938ca1acda05dffb02d88692fed30cf009b02ff99", kill_on_drop: false }`
[INFO] [stdout] cee5c95ef4b646dc41f7ec3938ca1acda05dffb02d88692fed30cf009b02ff99
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] e7a7163985c08cad70db95ae956b2295b8699ac742cd576e38dc087f87dcb309
[INFO] running `Command { std: "docker" "start" "-a" "e7a7163985c08cad70db95ae956b2295b8699ac742cd576e38dc087f87dcb309", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `r1`
[INFO] [stderr]   --> src/main.rs:15:13
[INFO] [stderr]    |
[INFO] [stderr] 15 |         let r1 = &mut s;
[INFO] [stderr]    |             ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `r2`
[INFO] [stderr]   --> src/main.rs:18:9
[INFO] [stderr]    |
[INFO] [stderr] 18 |     let r2 = &mut s;
[INFO] [stderr]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `r2`
[INFO] [stderr]   --> src/main.rs:21:9
[INFO] [stderr]    |
[INFO] [stderr] 21 |     let r2 = &s; //Works
[INFO] [stderr]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `guess`
[INFO] [stderr]   --> src/main.rs:48:9
[INFO] [stderr]    |
[INFO] [stderr] 48 |     let guess: u32 = "42".parse().expect("Not a number!");
[INFO] [stderr]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_guess`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/main.rs:50:9
[INFO] [stderr]    |
[INFO] [stderr] 50 |     let x = 2.0;
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `y`
[INFO] [stderr]   --> src/main.rs:51:9
[INFO] [stderr]    |
[INFO] [stderr] 51 |     let y: f32 = 3.0;
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `sum`
[INFO] [stderr]   --> src/main.rs:54:9
[INFO] [stderr]    |
[INFO] [stderr] 54 |     let sum = 5 + 10;
[INFO] [stderr]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_sum`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `difference`
[INFO] [stderr]   --> src/main.rs:57:9
[INFO] [stderr]    |
[INFO] [stderr] 57 |     let difference = 95.5 - 4.3;
[INFO] [stderr]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_difference`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `product`
[INFO] [stderr]   --> src/main.rs:60:9
[INFO] [stderr]    |
[INFO] [stderr] 60 |     let product = 4 * 30;
[INFO] [stderr]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_product`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `quotient`
[INFO] [stderr]   --> src/main.rs:63:9
[INFO] [stderr]    |
[INFO] [stderr] 63 |     let quotient = 56.7 / 32.2;
[INFO] [stderr]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_quotient`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `remainder`
[INFO] [stderr]   --> src/main.rs:66:9
[INFO] [stderr]    |
[INFO] [stderr] 66 |     let remainder = 43 % 5;
[INFO] [stderr]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_remainder`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `t`
[INFO] [stderr]   --> src/main.rs:68:9
[INFO] [stderr]    |
[INFO] [stderr] 68 |     let t = true;
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `f`
[INFO] [stderr]   --> src/main.rs:69:9
[INFO] [stderr]    |
[INFO] [stderr] 69 |     let f: bool = false;
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `c`
[INFO] [stderr]   --> src/main.rs:71:9
[INFO] [stderr]    |
[INFO] [stderr] 71 |     let c = 'c';
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `z`
[INFO] [stderr]   --> src/main.rs:72:9
[INFO] [stderr]    |
[INFO] [stderr] 72 |     let z = 'z';
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `heart_eyed_cat`
[INFO] [stderr]   --> src/main.rs:73:9
[INFO] [stderr]    |
[INFO] [stderr] 73 |     let heart_eyed_cat = '😻';
[INFO] [stderr]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_heart_eyed_cat`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/main.rs:77:10
[INFO] [stderr]    |
[INFO] [stderr] 77 |     let (x,y,z)  = tup;
[INFO] [stderr]    |          ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `z`
[INFO] [stderr]   --> src/main.rs:77:14
[INFO] [stderr]    |
[INFO] [stderr] 77 |     let (x,y,z)  = tup;
[INFO] [stderr]    |              ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `five_hundred`
[INFO] [stderr]   --> src/main.rs:82:9
[INFO] [stderr]    |
[INFO] [stderr] 82 |     let five_hundred = x.0;
[INFO] [stderr]    |         ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_five_hundred`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `six_point_four`
[INFO] [stderr]   --> src/main.rs:83:9
[INFO] [stderr]    |
[INFO] [stderr] 83 |     let six_point_four = x.1;
[INFO] [stderr]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_six_point_four`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `one`
[INFO] [stderr]   --> src/main.rs:84:9
[INFO] [stderr]    |
[INFO] [stderr] 84 |     let one = x.2;
[INFO] [stderr]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_one`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `spaces`
[INFO] [stderr]   --> src/main.rs:94:9
[INFO] [stderr]    |
[INFO] [stderr] 94 |     let spaces = spaces.len();
[INFO] [stderr]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_spaces`
[INFO] [stderr] 
[INFO] [stdout] 
[INFO] [stderr] warning: function is never used: `ownership`
[INFO] [stdout] running 0 tests
[INFO] [stderr]   --> src/main.rs:29:4
[INFO] [stdout] 
[INFO] [stderr]    |
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stderr] 29 | fn ownership() {
[INFO] [stdout] 
[INFO] [stderr]    |    ^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `data_types`
[INFO] [stderr]   --> src/main.rs:47:4
[INFO] [stderr]    |
[INFO] [stderr] 47 | fn data_types() {
[INFO] [stderr]    |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `shadowing`
[INFO] [stderr]   --> src/main.rs:87:4
[INFO] [stderr]    |
[INFO] [stderr] 87 | fn shadowing() {
[INFO] [stderr]    |    ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `mutable_variables`
[INFO] [stderr]   --> src/main.rs:97:4
[INFO] [stderr]    |
[INFO] [stderr] 97 | fn mutable_variables() {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: `rust_book` (bin "rust_book" test) generated 26 warnings
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/rust_book-efb57bf2658efcdb)
[INFO] running `Command { std: "docker" "inspect" "e7a7163985c08cad70db95ae956b2295b8699ac742cd576e38dc087f87dcb309", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e7a7163985c08cad70db95ae956b2295b8699ac742cd576e38dc087f87dcb309", kill_on_drop: false }`
[INFO] [stdout] e7a7163985c08cad70db95ae956b2295b8699ac742cd576e38dc087f87dcb309