[INFO] cloning repository https://github.com/tokiwadai/rust_prog_lang
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tokiwadai/rust_prog_lang" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftokiwadai%2Frust_prog_lang", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftokiwadai%2Frust_prog_lang'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 33dae1fc64c5b7520cd7228a492d29aea1b54aaf
[INFO] checking tokiwadai/rust_prog_lang against master#e22b61bff0bdd08be7665607cb7be3748c8a35d2 for pr-74627
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftokiwadai%2Frust_prog_lang" "/workspace/builds/worker-8/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tokiwadai/rust_prog_lang on toolchain e22b61bff0bdd08be7665607cb7be3748c8a35d2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+e22b61bff0bdd08be7665607cb7be3748c8a35d2" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/tokiwadai/rust_prog_lang
[INFO] finished tweaking git repo https://github.com/tokiwadai/rust_prog_lang
[INFO] tweaked toml for git repo https://github.com/tokiwadai/rust_prog_lang written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate git repo https://github.com/tokiwadai/rust_prog_lang already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+e22b61bff0bdd08be7665607cb7be3748c8a35d2" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+e22b61bff0bdd08be7665607cb7be3748c8a35d2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 91e3bb8141dbbf5735caacdd6b072c389b8c6c9c0d359cc1a8adc2e6bd2a35fe
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "91e3bb8141dbbf5735caacdd6b072c389b8c6c9c0d359cc1a8adc2e6bd2a35fe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "91e3bb8141dbbf5735caacdd6b072c389b8c6c9c0d359cc1a8adc2e6bd2a35fe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "91e3bb8141dbbf5735caacdd6b072c389b8c6c9c0d359cc1a8adc2e6bd2a35fe", kill_on_drop: false }`
[INFO] [stdout] 91e3bb8141dbbf5735caacdd6b072c389b8c6c9c0d359cc1a8adc2e6bd2a35fe
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+e22b61bff0bdd08be7665607cb7be3748c8a35d2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] a7f5529ad390d2b1d47db013ed2ced09732c519dddbdaa5a90291457f33d49d9
[INFO] running `Command { std: "docker" "start" "-a" "a7f5529ad390d2b1d47db013ed2ced09732c519dddbdaa5a90291457f33d49d9", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_prog_lang v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `order1`
[INFO] [stdout]   --> src/lib.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let order1 = back_of_house::Appetizer::Soup;
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_order1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `order2`
[INFO] [stdout]   --> src/lib.rs:58:9
[INFO] [stdout]    |
[INFO] [stdout] 58 |     let order2 = back_of_house::Appetizer::Salad;
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_order2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `seat_at_table`
[INFO] [stdout]  --> src/front_of_house/hosting.rs:2:4
[INFO] [stdout]   |
[INFO] [stdout] 2 | fn seat_at_table() {}
[INFO] [stdout]   |    ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `take_order`
[INFO] [stdout]  --> src/front_of_house.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 |     fn take_order() {}
[INFO] [stdout]   |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `serve_order`
[INFO] [stdout]  --> src/front_of_house.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 |     fn serve_order() {}
[INFO] [stdout]   |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `take_payment`
[INFO] [stdout]  --> src/front_of_house.rs:6:8
[INFO] [stdout]   |
[INFO] [stdout] 6 |     fn take_payment() {}
[INFO] [stdout]   |        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `serve_order`
[INFO] [stdout]   --> src/lib.rs:16:4
[INFO] [stdout]    |
[INFO] [stdout] 16 | fn serve_order() {}
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `seasonal_fruit`
[INFO] [stdout]   --> src/lib.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |         seasonal_fruit: String,
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `cook_order`
[INFO] [stdout]   --> src/lib.rs:33:8
[INFO] [stdout]    |
[INFO] [stdout] 33 |     fn cook_order() {}
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `fix_incorrect_order`
[INFO] [stdout]   --> src/lib.rs:34:8
[INFO] [stdout]    |
[INFO] [stdout] 34 |     fn fix_incorrect_order() {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `order1`
[INFO] [stdout]   --> src/lib.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let order1 = back_of_house::Appetizer::Soup;
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_order1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `order2`
[INFO] [stdout]   --> src/lib.rs:58:9
[INFO] [stdout]    |
[INFO] [stdout] 58 |     let order2 = back_of_house::Appetizer::Salad;
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_order2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `seat_at_table`
[INFO] [stdout]  --> src/front_of_house/hosting.rs:2:4
[INFO] [stdout]   |
[INFO] [stdout] 2 | fn seat_at_table() {}
[INFO] [stdout]   |    ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `take_order`
[INFO] [stdout]  --> src/front_of_house.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 |     fn take_order() {}
[INFO] [stdout]   |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `serve_order`
[INFO] [stdout]  --> src/front_of_house.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 |     fn serve_order() {}
[INFO] [stdout]   |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `take_payment`
[INFO] [stdout]  --> src/front_of_house.rs:6:8
[INFO] [stdout]   |
[INFO] [stdout] 6 |     fn take_payment() {}
[INFO] [stdout]   |        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `serve_order`
[INFO] [stdout]   --> src/lib.rs:16:4
[INFO] [stdout]    |
[INFO] [stdout] 16 | fn serve_order() {}
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `seasonal_fruit`
[INFO] [stdout]   --> src/lib.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |         seasonal_fruit: String,
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `cook_order`
[INFO] [stdout]   --> src/lib.rs:33:8
[INFO] [stdout]    |
[INFO] [stdout] 33 |     fn cook_order() {}
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `fix_incorrect_order`
[INFO] [stdout]   --> src/lib.rs:34:8
[INFO] [stdout]    |
[INFO] [stdout] 34 |     fn fix_incorrect_order() {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0432]: unresolved import `adder`
[INFO] [stdout]  --> tests/integration_test.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use adder;
[INFO] [stdout]   |     ^^^^^ no `adder` external crate
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/chap8/4_string_samples.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let mut s = String::new();
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/chap8/4_string_samples.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let s = data.to_string();
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/chap8/4_string_samples.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let s = "initial contents".to_string();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/chap8/4_string_samples.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let s = String::from("initial contents");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/chap8/4_string_samples.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let hello = String::from("السلام علیكم");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/chap8/4_string_samples.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let hello = String::from("Dobrý den");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/chap8/4_string_samples.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let hello = String::from("Hello");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/chap8/4_string_samples.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let hello = String::from("Здравствуйте");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/chap8/4_string_samples.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let hello = String::from("Hola");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/bin/chap8/4_string_samples.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let mut s = String::new();
[INFO] [stdout]   |         ----^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_prog_lang`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: function is never used: `read_username_from_file`
[INFO] [stdout]   --> src/bin/chap9/4_propagating_error.rs:12:4
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_username_from_file2`
[INFO] [stdout]   --> src/bin/chap9/4_propagating_error.rs:29:4
[INFO] [stdout]    |
[INFO] [stdout] 29 | fn read_username_from_file2() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_username_from_file3`
[INFO] [stdout]   --> src/bin/chap9/4_propagating_error.rs:38:4
[INFO] [stdout]    |
[INFO] [stdout] 38 | fn read_username_from_file3() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/bin/chap10/2_trait_samples.rs:57:24
[INFO] [stdout]    |
[INFO] [stdout] 57 | fn some_function<T, U>(t: &T, u: &U) -> i32
[INFO] [stdout]    |                        ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> src/bin/chap10/2_trait_samples.rs:57:31
[INFO] [stdout]    |
[INFO] [stdout] 57 | fn some_function<T, U>(t: &T, u: &U) -> i32
[INFO] [stdout]    |                               ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `some_function`
[INFO] [stdout]   --> src/bin/chap10/2_trait_samples.rs:57:4
[INFO] [stdout]    |
[INFO] [stdout] 57 | fn some_function<T, U>(t: &T, u: &U) -> i32
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `name`
[INFO] [stdout]  --> src/bin/chap11/1_test_samples.rs:9:18
[INFO] [stdout]   |
[INFO] [stdout] 9 | pub fn greeting2(name: &str) -> String {
[INFO] [stdout]   |                  ^^^^ help: if this is intentional, prefix it with an underscore: `_name`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `value`
[INFO] [stdout]   --> src/bin/chap11/1_test_samples.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 |     value: i32,
[INFO] [stdout]    |     ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `newB` should have a snake case name
[INFO] [stdout]   --> src/bin/chap11/1_test_samples.rs:24:12
[INFO] [stdout]    |
[INFO] [stdout] 24 |     pub fn newB(value: i32) -> Guess {
[INFO] [stdout]    |            ^^^^ help: convert the identifier to snake case: `new_b`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `greater_than_100B` should have a snake case name
[INFO] [stdout]   --> src/bin/chap11/1_test_samples.rs:77:8
[INFO] [stdout]    |
[INFO] [stdout] 77 |     fn greater_than_100B() {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^ help: convert the identifier to snake case: `greater_than_100_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/chap9/3_result_matching_samples.rs:43:9
[INFO] [stdout]    |
[INFO] [stdout] 43 |     let f = File::open("hello2.txt")
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "a7f5529ad390d2b1d47db013ed2ced09732c519dddbdaa5a90291457f33d49d9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a7f5529ad390d2b1d47db013ed2ced09732c519dddbdaa5a90291457f33d49d9", kill_on_drop: false }`
[INFO] [stdout] a7f5529ad390d2b1d47db013ed2ced09732c519dddbdaa5a90291457f33d49d9