[INFO] cloning repository https://github.com/lucke84/playing_around_with_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/lucke84/playing_around_with_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flucke84%2Fplaying_around_with_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flucke84%2Fplaying_around_with_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 258cf4006127f9f86cf750b991e2051b64bf8a08
[INFO] checking lucke84/playing_around_with_rust/258cf4006127f9f86cf750b991e2051b64bf8a08 against master#8c52f735abd1af9a73941b78fe7ed2ab08b9c0dd for pr-150557
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flucke84%2Fplaying_around_with_rust" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/lucke84/playing_around_with_rust
[INFO] finished tweaking git repo https://github.com/lucke84/playing_around_with_rust
[INFO] tweaked toml for git repo https://github.com/lucke84/playing_around_with_rust written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/lucke84/playing_around_with_rust on toolchain 8c52f735abd1af9a73941b78fe7ed2ab08b9c0dd
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+8c52f735abd1af9a73941b78fe7ed2ab08b9c0dd" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/lucke84/playing_around_with_rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+8c52f735abd1af9a73941b78fe7ed2ab08b9c0dd" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: no edition set: defaulting to the 2015 edition while the latest is 2024
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:98afbf2d16093dec2546ff8915fddc74e65664aa03fc460b3712b1c2c54a33e4" "/opt/rustwide/cargo-home/bin/cargo" "+8c52f735abd1af9a73941b78fe7ed2ab08b9c0dd" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b92fea68454d1dec4811baad30f282f57d1b88475373aa5327ddfb165c69697c
[INFO] running `Command { std: "docker" "start" "-a" "b92fea68454d1dec4811baad30f282f57d1b88475373aa5327ddfb165c69697c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b92fea68454d1dec4811baad30f282f57d1b88475373aa5327ddfb165c69697c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b92fea68454d1dec4811baad30f282f57d1b88475373aa5327ddfb165c69697c", kill_on_drop: false }`
[INFO] [stdout] b92fea68454d1dec4811baad30f282f57d1b88475373aa5327ddfb165c69697c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:98afbf2d16093dec2546ff8915fddc74e65664aa03fc460b3712b1c2c54a33e4" "/opt/rustwide/cargo-home/bin/cargo" "+8c52f735abd1af9a73941b78fe7ed2ab08b9c0dd" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 65805e0e7517849f0cc65cb1ef9319e9c7b64e3880288aa666590c1e2100810a
[INFO] running `Command { std: "docker" "start" "-a" "65805e0e7517849f0cc65cb1ef9319e9c7b64e3880288aa666590c1e2100810a", kill_on_drop: false }`
[INFO] [stderr] warning: no edition set: defaulting to the 2015 edition while the latest is 2024
[INFO] [stderr]     Checking playing_around_with_rust v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/main.rs:37:13
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let j = (i = 6);                            // the value of an assignment is an empty tuple: so j has the value (), not 6
[INFO] [stdout]    |             ^     ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 37 -     let j = (i = 6);                            // the value of an assignment is an empty tuple: so j has the value (), not 6
[INFO] [stdout] 37 +     let j = i = 6 ;                            // the value of an assignment is an empty tuple: so j has the value (), not 6
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/main.rs:37:13
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let j = (i = 6);                            // the value of an assignment is an empty tuple: so j has the value (), not 6
[INFO] [stdout]    |             ^     ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 37 -     let j = (i = 6);                            // the value of an assignment is an empty tuple: so j has the value (), not 6
[INFO] [stdout] 37 +     let j = i = 6 ;                            // the value of an assignment is an empty tuple: so j has the value (), not 6
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]    --> src/main.rs:137:5
[INFO] [stdout]     |
[INFO] [stdout] 136 |     return 1;                                   // explicit return keyword, semicolon required
[INFO] [stdout]     |     -------- any code following this expression is unreachable
[INFO] [stdout] 137 |     x                                           // never executed
[INFO] [stdout]     |     ^ unreachable expression
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unreachable_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:87:9
[INFO] [stdout]    |
[INFO] [stdout] 87 |     let mut mutable_array = [1.5, 2.3, 3.0]; // type [f64; 3]
[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: `a`
[INFO] [stdout]  --> src/main.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let a = 1;                                  // type i32 is infered
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]  --> src/main.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let b: i32 = 2;                             // type i32 is explicitly declared
[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/main.rs:10:10
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let (c, d) = (3, 4);                        // variable bindings of multiple vars at the same time
[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/main.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let (c, d) = (3, 4);                        // variable bindings of multiple vars at the same time
[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/main.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let e: i32;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_e`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `f` is assigned to, but never used
[INFO] [stdout]   --> src/main.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let mut f = 5;                              // make variable mutable
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: consider using `_f` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/main.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let f = "Look, I am text now";              // shadowing, and changing type!
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `j`
[INFO] [stdout]   --> src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let j = (i = 6);                            // the value of an assignment is an empty tuple: so j has the value (), not 6
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_j`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a_boolean`
[INFO] [stdout]   --> src/main.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |     let a_boolean = true;                         // with inference
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_a_boolean`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `another_boolean`
[INFO] [stdout]   --> src/main.rs:60:9
[INFO] [stdout]    |
[INFO] [stdout] 60 |     let another_boolean: bool = false;            // without inference
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_another_boolean`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `this_is_a_char`
[INFO] [stdout]   --> src/main.rs:63:9
[INFO] [stdout]    |
[INFO] [stdout] 63 |     let this_is_a_char = 'x';                    // delimited by a single quote/tick
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_this_is_a_char`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `two_hearts_char`
[INFO] [stdout]   --> src/main.rs:64:9
[INFO] [stdout]    |
[INFO] [stdout] 64 |     let two_hearts_char = '💕';                   // any unicode char (due to the fact that they are UTF-32, all chars are 4 bytes i...
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_two_hearts_char`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `an_integer`
[INFO] [stdout]   --> src/main.rs:67:9
[INFO] [stdout]    |
[INFO] [stdout] 67 |     let an_integer = 42;                         // default with inference (type i32 - The 32-bit signed integer type)
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_an_integer`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a_float`
[INFO] [stdout]   --> src/main.rs:68:9
[INFO] [stdout]    |
[INFO] [stdout] 68 |     let a_float = 1.0;                           // default with inference (type f64 - The 64-bit floating point type)
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_a_float`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `complete_slice`
[INFO] [stdout]   --> src/main.rs:99:9
[INFO] [stdout]    |
[INFO] [stdout] 99 |     let complete_slice = &mutable_array[..];                  // [5, 7, 3, 23, 11]
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_complete_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `partial_slice`
[INFO] [stdout]    --> src/main.rs:100:9
[INFO] [stdout]     |
[INFO] [stdout] 100 |     let partial_slice = &mutable_array[1..3];                 // [7, 4] - from item at index 1 to item at index 3 (excluded)
[INFO] [stdout]     |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_partial_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `from_item_till_end_slice`
[INFO] [stdout]    --> src/main.rs:101:9
[INFO] [stdout]     |
[INFO] [stdout] 101 |     let from_item_till_end_slice = &mutable_array[1..];       // [7, 4, 23, 11]
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_from_item_till_end_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `from_beginning_till_item_slice`
[INFO] [stdout]    --> src/main.rs:102:9
[INFO] [stdout]     |
[INFO] [stdout] 102 |     let from_beginning_till_item_slice = &mutable_array[..2]; // [5, 7]
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_from_beginning_till_item_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `tuple_one`
[INFO] [stdout]    --> src/main.rs:106:9
[INFO] [stdout]     |
[INFO] [stdout] 106 |     let tuple_one = (1, "one");
[INFO] [stdout]     |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_tuple_one`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `tuple_second_item`
[INFO] [stdout]    --> src/main.rs:123:9
[INFO] [stdout]     |
[INFO] [stdout] 123 |     let tuple_second_item = tuple_xy.1;
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_tuple_second_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `f` is never read
[INFO] [stdout]   --> src/main.rs:19:5
[INFO] [stdout]    |
[INFO] [stdout] 19 |     f = 6;                                      // now I can assign a new value (of the same type!) to this variable
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `i` is never read
[INFO] [stdout]   --> src/main.rs:36:17
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let mut i = 5;
[INFO] [stdout]    |                 ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `tuple_xy` is never read
[INFO] [stdout]    --> src/main.rs:110:24
[INFO] [stdout]     |
[INFO] [stdout] 110 |     let mut tuple_xy = (0, "zero");
[INFO] [stdout]     |                        ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]    --> src/main.rs:135:22
[INFO] [stdout]     |
[INFO] [stdout] 135 | fn always_return_one(x: i32) -> i32 {
[INFO] [stdout]     |                      ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `diverges` is never used
[INFO] [stdout]    --> src/main.rs:140:4
[INFO] [stdout]     |
[INFO] [stdout] 140 | fn diverges() -> ! {                            // defines the return type as "diverges" using the bang symbol
[INFO] [stdout]     |    ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]    --> src/main.rs:137:5
[INFO] [stdout]     |
[INFO] [stdout] 136 |     return 1;                                   // explicit return keyword, semicolon required
[INFO] [stdout]     |     -------- any code following this expression is unreachable
[INFO] [stdout] 137 |     x                                           // never executed
[INFO] [stdout]     |     ^ unreachable expression
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unreachable_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:87:9
[INFO] [stdout]    |
[INFO] [stdout] 87 |     let mut mutable_array = [1.5, 2.3, 3.0]; // type [f64; 3]
[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: `a`
[INFO] [stdout]  --> src/main.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let a = 1;                                  // type i32 is infered
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]  --> src/main.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let b: i32 = 2;                             // type i32 is explicitly declared
[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/main.rs:10:10
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let (c, d) = (3, 4);                        // variable bindings of multiple vars at the same time
[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/main.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let (c, d) = (3, 4);                        // variable bindings of multiple vars at the same time
[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/main.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let e: i32;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_e`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `f` is assigned to, but never used
[INFO] [stdout]   --> src/main.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let mut f = 5;                              // make variable mutable
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: consider using `_f` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/main.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let f = "Look, I am text now";              // shadowing, and changing type!
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `j`
[INFO] [stdout]   --> src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let j = (i = 6);                            // the value of an assignment is an empty tuple: so j has the value (), not 6
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_j`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a_boolean`
[INFO] [stdout]   --> src/main.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |     let a_boolean = true;                         // with inference
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_a_boolean`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `another_boolean`
[INFO] [stdout]   --> src/main.rs:60:9
[INFO] [stdout]    |
[INFO] [stdout] 60 |     let another_boolean: bool = false;            // without inference
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_another_boolean`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `this_is_a_char`
[INFO] [stdout]   --> src/main.rs:63:9
[INFO] [stdout]    |
[INFO] [stdout] 63 |     let this_is_a_char = 'x';                    // delimited by a single quote/tick
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_this_is_a_char`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `two_hearts_char`
[INFO] [stdout]   --> src/main.rs:64:9
[INFO] [stdout]    |
[INFO] [stdout] 64 |     let two_hearts_char = '💕';                   // any unicode char (due to the fact that they are UTF-32, all chars are 4 bytes i...
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_two_hearts_char`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `an_integer`
[INFO] [stdout]   --> src/main.rs:67:9
[INFO] [stdout]    |
[INFO] [stdout] 67 |     let an_integer = 42;                         // default with inference (type i32 - The 32-bit signed integer type)
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_an_integer`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a_float`
[INFO] [stdout]   --> src/main.rs:68:9
[INFO] [stdout]    |
[INFO] [stdout] 68 |     let a_float = 1.0;                           // default with inference (type f64 - The 64-bit floating point type)
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_a_float`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `complete_slice`
[INFO] [stdout]   --> src/main.rs:99:9
[INFO] [stdout]    |
[INFO] [stdout] 99 |     let complete_slice = &mutable_array[..];                  // [5, 7, 3, 23, 11]
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_complete_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `partial_slice`
[INFO] [stdout]    --> src/main.rs:100:9
[INFO] [stdout]     |
[INFO] [stdout] 100 |     let partial_slice = &mutable_array[1..3];                 // [7, 4] - from item at index 1 to item at index 3 (excluded)
[INFO] [stdout]     |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_partial_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `from_item_till_end_slice`
[INFO] [stdout]    --> src/main.rs:101:9
[INFO] [stdout]     |
[INFO] [stdout] 101 |     let from_item_till_end_slice = &mutable_array[1..];       // [7, 4, 23, 11]
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_from_item_till_end_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `from_beginning_till_item_slice`
[INFO] [stdout]    --> src/main.rs:102:9
[INFO] [stdout]     |
[INFO] [stdout] 102 |     let from_beginning_till_item_slice = &mutable_array[..2]; // [5, 7]
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_from_beginning_till_item_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `tuple_one`
[INFO] [stdout]    --> src/main.rs:106:9
[INFO] [stdout]     |
[INFO] [stdout] 106 |     let tuple_one = (1, "one");
[INFO] [stdout]     |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_tuple_one`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `tuple_second_item`
[INFO] [stdout]    --> src/main.rs:123:9
[INFO] [stdout]     |
[INFO] [stdout] 123 |     let tuple_second_item = tuple_xy.1;
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_tuple_second_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `f` is never read
[INFO] [stdout]   --> src/main.rs:19:5
[INFO] [stdout]    |
[INFO] [stdout] 19 |     f = 6;                                      // now I can assign a new value (of the same type!) to this variable
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `i` is never read
[INFO] [stdout]   --> src/main.rs:36:17
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let mut i = 5;
[INFO] [stdout]    |                 ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `tuple_xy` is never read
[INFO] [stdout]    --> src/main.rs:110:24
[INFO] [stdout]     |
[INFO] [stdout] 110 |     let mut tuple_xy = (0, "zero");
[INFO] [stdout]     |                        ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]    --> src/main.rs:135:22
[INFO] [stdout]     |
[INFO] [stdout] 135 | fn always_return_one(x: i32) -> i32 {
[INFO] [stdout]     |                      ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `diverges` is never used
[INFO] [stdout]    --> src/main.rs:140:4
[INFO] [stdout]     |
[INFO] [stdout] 140 | fn diverges() -> ! {                            // defines the return type as "diverges" using the bang symbol
[INFO] [stdout]     |    ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.19s
[INFO] running `Command { std: "docker" "inspect" "65805e0e7517849f0cc65cb1ef9319e9c7b64e3880288aa666590c1e2100810a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "65805e0e7517849f0cc65cb1ef9319e9c7b64e3880288aa666590c1e2100810a", kill_on_drop: false }`
[INFO] [stdout] 65805e0e7517849f0cc65cb1ef9319e9c7b64e3880288aa666590c1e2100810a
