[INFO] cloning repository https://github.com/NamesMark/rust-bits
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/NamesMark/rust-bits" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FNamesMark%2Frust-bits", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FNamesMark%2Frust-bits'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a5325acbfefc376940f03e6c80ac736f1ce5d263
[INFO] checking NamesMark/rust-bits/a5325acbfefc376940f03e6c80ac736f1ce5d263 against master#ab869e094a907cc5d19b4080f22eccaf347f1f95 for pr-129604
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FNamesMark%2Frust-bits" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/NamesMark/rust-bits on toolchain ab869e094a907cc5d19b4080f22eccaf347f1f95
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/NamesMark/rust-bits
[INFO] finished tweaking git repo https://github.com/NamesMark/rust-bits
[INFO] tweaked toml for git repo https://github.com/NamesMark/rust-bits written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/NamesMark/rust-bits 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" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 438a8c05811c93b318a5248650e42dfc2129ed8fb46b878c4286cca26bff6da7
[INFO] running `Command { std: "docker" "start" "-a" "438a8c05811c93b318a5248650e42dfc2129ed8fb46b878c4286cca26bff6da7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "438a8c05811c93b318a5248650e42dfc2129ed8fb46b878c4286cca26bff6da7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "438a8c05811c93b318a5248650e42dfc2129ed8fb46b878c4286cca26bff6da7", kill_on_drop: false }`
[INFO] [stdout] 438a8c05811c93b318a5248650e42dfc2129ed8fb46b878c4286cca26bff6da7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a1a90a7f5df04f23d57b0200aa13d7920aece0e6baf040c5193f4410d074de29
[INFO] running `Command { std: "docker" "start" "-a" "a1a90a7f5df04f23d57b0200aa13d7920aece0e6baf040c5193f4410d074de29", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.147
[INFO] [stderr]     Checking getrandom v0.2.10
[INFO] [stderr]     Checking rand_core v0.6.4
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking bits-of-rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `E`
[INFO] [stdout]   --> src/bin/essentials/number_guessing.rs:20:17
[INFO] [stdout]    |
[INFO] [stdout] 20 |             Err(E) => {
[INFO] [stdout]    |                 ^ help: if this is intentional, prefix it with an underscore: `_E`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `E`
[INFO] [stdout]   --> src/bin/essentials/number_guessing.rs:20:17
[INFO] [stdout]    |
[INFO] [stdout] 20 |             Err(E) => {
[INFO] [stdout]    |                 ^ help: if this is intentional, prefix it with an underscore: `_E`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/bin/essentials/number_guessing.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/bin/essentials/args.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/bin/essentials/files.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn main () {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/bin/essentials/check_roster.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Rectangle` is never constructed
[INFO] [stdout]  --> src/bin/essentials/rectangle_struct.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct Rectangle {
[INFO] [stdout]   |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `get_area`, `scale`, and `new` are never used
[INFO] [stdout]   --> src/bin/essentials/rectangle_struct.rs:7:8
[INFO] [stdout]    |
[INFO] [stdout] 6  | impl Rectangle {
[INFO] [stdout]    | -------------- associated items in this implementation
[INFO] [stdout] 7  |     fn get_area(&self) -> f64 {
[INFO] [stdout]    |        ^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 11 |     fn scale(&mut self, multiplier: f64) {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 16 |     fn new (width: f64, height: f64) -> Rectangle {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]   --> src/bin/essentials/rectangle_struct.rs:24:8
[INFO] [stdout]    |
[INFO] [stdout] 24 | pub fn main() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `sum_boxes` is never used
[INFO] [stdout]  --> src/bin/essentials/sum_boxes.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn sum_boxes<T: Add<Output = T>>(x: Box<T>, y: Box<T>) -> Box<T> {
[INFO] [stdout]   |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/bin/essentials/sum_boxes.rs:7:8
[INFO] [stdout]   |
[INFO] [stdout] 7 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Satellite` is never constructed
[INFO] [stdout]  --> src/bin/essentials/display_impl.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | struct Satellite {
[INFO] [stdout]   |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Altitude` is never used
[INFO] [stdout]   --> src/bin/essentials/display_impl.rs:27:7
[INFO] [stdout]    |
[INFO] [stdout] 27 | trait Altitude {
[INFO] [stdout]    |       ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]   --> src/bin/essentials/display_impl.rs:41:8
[INFO] [stdout]    |
[INFO] [stdout] 41 | pub fn main() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Location` is never used
[INFO] [stdout]  --> src/bin/essentials/enums.rs:3:6
[INFO] [stdout]   |
[INFO] [stdout] 3 | enum Location {
[INFO] [stdout]   |      ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `display` is never used
[INFO] [stdout]   --> src/bin/essentials/enums.rs:10:8
[INFO] [stdout]    |
[INFO] [stdout] 9  | impl Location {
[INFO] [stdout]    | ------------- method in this implementation
[INFO] [stdout] 10 |     fn display(&self) {
[INFO] [stdout]    |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]   --> src/bin/essentials/enums.rs:27:8
[INFO] [stdout]    |
[INFO] [stdout] 27 | pub fn main() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/bin/essentials/number_guessing.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/essentials/number_guessing.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |         io::stdin().read_line(&mut buffer);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 14 |         let _ = io::stdin().read_line(&mut buffer);
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `E` should have a snake case name
[INFO] [stdout]   --> src/bin/essentials/number_guessing.rs:20:17
[INFO] [stdout]    |
[INFO] [stdout] 20 |             Err(E) => {
[INFO] [stdout]    |                 ^ help: convert the identifier to snake case: `e`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/essentials/files.rs:23:5
[INFO] [stdout]    |
[INFO] [stdout] 23 |     fs::write("../assets/speech.txt", speech);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let _ = fs::write("../assets/speech.txt", speech);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/essentials/files.rs:27:5
[INFO] [stdout]    |
[INFO] [stdout] 27 |     file.write(b"\n...And cool");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let _ = file.write(b"\n...And cool");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/bin/essentials/args.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/bin/essentials/files.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn main () {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/bin/essentials/check_roster.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Rectangle` is never constructed
[INFO] [stdout]  --> src/bin/essentials/rectangle_struct.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct Rectangle {
[INFO] [stdout]   |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `get_area`, `scale`, and `new` are never used
[INFO] [stdout]   --> src/bin/essentials/rectangle_struct.rs:7:8
[INFO] [stdout]    |
[INFO] [stdout] 6  | impl Rectangle {
[INFO] [stdout]    | -------------- associated items in this implementation
[INFO] [stdout] 7  |     fn get_area(&self) -> f64 {
[INFO] [stdout]    |        ^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 11 |     fn scale(&mut self, multiplier: f64) {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 16 |     fn new (width: f64, height: f64) -> Rectangle {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]   --> src/bin/essentials/rectangle_struct.rs:24:8
[INFO] [stdout]    |
[INFO] [stdout] 24 | pub fn main() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `sum_boxes` is never used
[INFO] [stdout]  --> src/bin/essentials/sum_boxes.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn sum_boxes<T: Add<Output = T>>(x: Box<T>, y: Box<T>) -> Box<T> {
[INFO] [stdout]   |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]  --> src/bin/essentials/sum_boxes.rs:7:8
[INFO] [stdout]   |
[INFO] [stdout] 7 | pub fn main() {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Satellite` is never constructed
[INFO] [stdout]  --> src/bin/essentials/display_impl.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | struct Satellite {
[INFO] [stdout]   |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Altitude` is never used
[INFO] [stdout]   --> src/bin/essentials/display_impl.rs:27:7
[INFO] [stdout]    |
[INFO] [stdout] 27 | trait Altitude {
[INFO] [stdout]    |       ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]   --> src/bin/essentials/display_impl.rs:41:8
[INFO] [stdout]    |
[INFO] [stdout] 41 | pub fn main() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Location` is never used
[INFO] [stdout]  --> src/bin/essentials/enums.rs:3:6
[INFO] [stdout]   |
[INFO] [stdout] 3 | enum Location {
[INFO] [stdout]   |      ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `display` is never used
[INFO] [stdout]   --> src/bin/essentials/enums.rs:10:8
[INFO] [stdout]    |
[INFO] [stdout] 9  | impl Location {
[INFO] [stdout]    | ------------- method in this implementation
[INFO] [stdout] 10 |     fn display(&self) {
[INFO] [stdout]    |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main` is never used
[INFO] [stdout]   --> src/bin/essentials/enums.rs:27:8
[INFO] [stdout]    |
[INFO] [stdout] 27 | pub fn main() {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/essentials/number_guessing.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |         io::stdin().read_line(&mut buffer);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 14 |         let _ = io::stdin().read_line(&mut buffer);
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `E` should have a snake case name
[INFO] [stdout]   --> src/bin/essentials/number_guessing.rs:20:17
[INFO] [stdout]    |
[INFO] [stdout] 20 |             Err(E) => {
[INFO] [stdout]    |                 ^ help: convert the identifier to snake case: `e`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/essentials/files.rs:23:5
[INFO] [stdout]    |
[INFO] [stdout] 23 |     fs::write("../assets/speech.txt", speech);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let _ = fs::write("../assets/speech.txt", speech);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/essentials/files.rs:27:5
[INFO] [stdout]    |
[INFO] [stdout] 27 |     file.write(b"\n...And cool");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let _ = file.write(b"\n...And cool");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 20 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 20 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 3.03s
[INFO] running `Command { std: "docker" "inspect" "a1a90a7f5df04f23d57b0200aa13d7920aece0e6baf040c5193f4410d074de29", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a1a90a7f5df04f23d57b0200aa13d7920aece0e6baf040c5193f4410d074de29", kill_on_drop: false }`
[INFO] [stdout] a1a90a7f5df04f23d57b0200aa13d7920aece0e6baf040c5193f4410d074de29