[INFO] updating cached repository https://github.com/CharlesGe129/learn_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
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[INFO] [stdout] fc393476917d2ec95a39b0022e045a93291122bb
[INFO] checking CharlesGe129/learn_rust/fc393476917d2ec95a39b0022e045a93291122bb against master#ab869e094a907cc5d19b4080f22eccaf347f1f95 for pr-129604
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCharlesGe129%2Flearn_rust" "/workspace/builds/worker-1-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/CharlesGe129/learn_rust 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/CharlesGe129/learn_rust
[INFO] finished tweaking git repo https://github.com/CharlesGe129/learn_rust
[INFO] tweaked toml for git repo https://github.com/CharlesGe129/learn_rust written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/CharlesGe129/learn_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" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] 2d75dfd73a100f58b2af9f4817b0ae5a6fd05226fe550c2607da4a2107d99738
[INFO] running `Command { std: "docker" "start" "-a" "2d75dfd73a100f58b2af9f4817b0ae5a6fd05226fe550c2607da4a2107d99738", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2d75dfd73a100f58b2af9f4817b0ae5a6fd05226fe550c2607da4a2107d99738", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2d75dfd73a100f58b2af9f4817b0ae5a6fd05226fe550c2607da4a2107d99738", kill_on_drop: false }`
[INFO] [stdout] 2d75dfd73a100f58b2af9f4817b0ae5a6fd05226fe550c2607da4a2107d99738
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] 76f88463996856394fdd080b6e0449447ca04d4e53238bb3e18f8ed917293786
[INFO] running `Command { std: "docker" "start" "-a" "76f88463996856394fdd080b6e0449447ca04d4e53238bb3e18f8ed917293786", kill_on_drop: false }`
[INFO] [stderr]     Checking learn_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: type `Point_mut` should have an upper camel case name
[INFO] [stdout]   --> src/struct.rs:44:12
[INFO] [stdout]    |
[INFO] [stdout] 44 |     struct Point_mut {
[INFO] [stdout]    |            ^^^^^^^^^ help: convert the identifier to upper camel case: `PointMut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_camel_case_types)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused label
[INFO] [stdout]   --> src/control_flow.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |         'inner: loop {
[INFO] [stdout]    |         ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_labels)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type `Point_mut` should have an upper camel case name
[INFO] [stdout]   --> src/struct.rs:44:12
[INFO] [stdout]    |
[INFO] [stdout] 44 |     struct Point_mut {
[INFO] [stdout]    |            ^^^^^^^^^ help: convert the identifier to upper camel case: `PointMut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_camel_case_types)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `...` range patterns are deprecated
[INFO] [stdout]   --> src/control_flow.rs:44:14
[INFO] [stdout]    |
[INFO] [stdout] 44 |         e @ 1...5 => println!("Weekday from range {}", e),
[INFO] [stdout]    |              ^^^ help: use `..=` for an inclusive range
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(ellipsis_inclusive_range_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::env`
[INFO] [stdout]  --> src/problems/triangle_expensive_path.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     use std::env;
[INFO] [stdout]   |         ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused label
[INFO] [stdout]   --> src/control_flow.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |         'inner: loop {
[INFO] [stdout]    |         ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_labels)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `...` range patterns are deprecated
[INFO] [stdout]   --> src/control_flow.rs:44:14
[INFO] [stdout]    |
[INFO] [stdout] 44 |         e @ 1...5 => println!("Weekday from range {}", e),
[INFO] [stdout]    |              ^^^ help: use `..=` for an inclusive range
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(ellipsis_inclusive_range_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::env`
[INFO] [stdout]  --> src/problems/triangle_expensive_path.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     use std::env;
[INFO] [stdout]   |         ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated method `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/io.rs:34:68
[INFO] [stdout]    |
[INFO] [stdout] 34 |         Err(why) => panic!("couldn't open {}: {}", display, Error::description(&why)),
[INFO] [stdout]    |                                                                    ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated method `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/io.rs:34:68
[INFO] [stdout]    |
[INFO] [stdout] 34 |         Err(why) => panic!("couldn't open {}: {}", display, Error::description(&why)),
[INFO] [stdout]    |                                                                    ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated method `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/io.rs:40:70
[INFO] [stdout]    |
[INFO] [stdout] 40 |         Err(why) => println!("couldn't read {}: {}", display, Error::description(&why)),
[INFO] [stdout]    |                                                                      ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated method `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/io.rs:40:70
[INFO] [stdout]    |
[INFO] [stdout] 40 |         Err(why) => println!("couldn't read {}: {}", display, Error::description(&why)),
[INFO] [stdout]    |                                                                      ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated method `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/io.rs:58:68
[INFO] [stdout]    |
[INFO] [stdout] 58 |         Err(why) => panic!("couldn't open {}: {}", display, Error::description(&why)),
[INFO] [stdout]    |                                                                    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated method `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/io.rs:58:68
[INFO] [stdout]    |
[INFO] [stdout] 58 |         Err(why) => panic!("couldn't open {}: {}", display, Error::description(&why)),
[INFO] [stdout]    |                                                                    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated method `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/io.rs:63:74
[INFO] [stdout]    |
[INFO] [stdout] 63 |         Err(why) => println!("couldn't write to {}: {}", display, Error::description(&why)),
[INFO] [stdout]    |                                                                          ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated method `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/io.rs:63:74
[INFO] [stdout]    |
[INFO] [stdout] 63 |         Err(why) => println!("couldn't write to {}: {}", display, Error::description(&why)),
[INFO] [stdout]    |                                                                          ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/function.rs:44:31
[INFO] [stdout]    |
[INFO] [stdout] 44 |     fn factory(x: i32) -> Box<Fn(i32) -> i32> {
[INFO] [stdout]    |                               ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 44 |     fn factory(x: i32) -> Box<dyn Fn(i32) -> i32> {
[INFO] [stdout]    |                               +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/function.rs:44:31
[INFO] [stdout]    |
[INFO] [stdout] 44 |     fn factory(x: i32) -> Box<Fn(i32) -> i32> {
[INFO] [stdout]    |                               ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 44 |     fn factory(x: i32) -> Box<dyn Fn(i32) -> i32> {
[INFO] [stdout]    |                               +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]   --> src/control_flow.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |             break 'outer
[INFO] [stdout]    |             ------------ any code following this expression is unreachable
[INFO] [stdout] 34 |         }
[INFO] [stdout] 35 |         println!("No print, outer has been break");
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unreachable statement
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout]    = note: this warning originates in the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]   --> src/control_flow.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |             break 'outer
[INFO] [stdout]    |             ------------ any code following this expression is unreachable
[INFO] [stdout] 34 |         }
[INFO] [stdout] 35 |         println!("No print, outer has been break");
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unreachable statement
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout]    = note: this warning originates in the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/function.rs:55:21
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let translate: &Fn(i32) -> i32 = add_num;
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let translate: &dyn Fn(i32) -> i32 = add_num;
[INFO] [stdout]    |                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/function.rs:55:21
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let translate: &Fn(i32) -> i32 = add_num;
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let translate: &dyn Fn(i32) -> i32 = add_num;
[INFO] [stdout]    |                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]  --> src/array.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let v: Vec<i32> = Vec::new();
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]  --> src/array.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let v: Vec<i32> = vec![];
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/array.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let mut array: [i32; 3] = [0; 3];
[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] warning: unused variable: `v`
[INFO] [stdout]  --> src/array.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let v: Vec<i32> = Vec::new();
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]  --> src/array.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let v: Vec<i32> = vec![];
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]  --> src/str.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let hello = "hello world!";
[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/str.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let hello: &'static str = "hello world!";
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `hello` is never read
[INFO] [stdout]  --> src/str.rs:6:13
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let mut hello = String::new();
[INFO] [stdout]   |             ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[INFO] [stdout]   = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/array.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let mut array: [i32; 3] = [0; 3];
[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] warning: unused variable: `hello`
[INFO] [stdout]  --> src/str.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let hello = "hello world!";
[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/str.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let hello: &'static str = "hello world!";
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `hello` is never read
[INFO] [stdout]  --> src/str.rs:6:13
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let mut hello = String::new();
[INFO] [stdout]   |             ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[INFO] [stdout]   = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `point`
[INFO] [stdout]  --> src/struct.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let point = Point{x: 1, y: 2};
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_point`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `green`
[INFO] [stdout]   --> src/struct.rs:14:20
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let Color(red, green, blue) = android_green;
[INFO] [stdout]    |                    ^^^^^ help: if this is intentional, prefix it with an underscore: `_green`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `blue`
[INFO] [stdout]   --> src/struct.rs:14:27
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let Color(red, green, blue) = android_green;
[INFO] [stdout]    |                           ^^^^ help: if this is intentional, prefix it with an underscore: `_blue`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `point`
[INFO] [stdout]  --> src/struct.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let point = Point{x: 1, y: 2};
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_point`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `green`
[INFO] [stdout]   --> src/struct.rs:14:20
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let Color(red, green, blue) = android_green;
[INFO] [stdout]    |                    ^^^^^ help: if this is intentional, prefix it with an underscore: `_green`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `blue`
[INFO] [stdout]   --> src/struct.rs:14:27
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let Color(red, green, blue) = android_green;
[INFO] [stdout]    |                           ^^^^ help: if this is intentional, prefix it with an underscore: `_blue`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `num`
[INFO] [stdout]   --> src/function.rs:23:37
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let mut add_num = move |x: i32| num += x;
[INFO] [stdout]    |                                     ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: did you mean to capture by reference instead?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/function.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let mut temp = num;
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `num`
[INFO] [stdout]   --> src/function.rs:23:37
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let mut add_num = move |x: i32| num += x;
[INFO] [stdout]    |                                     ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: did you mean to capture by reference instead?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/function.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let mut temp = num;
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `couple`
[INFO] [stdout]   --> src/generics.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let couple = make_pair("male", "female");
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_couple`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `int_origin`
[INFO] [stdout]   --> src/generics.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let int_origin = Point { x: 0, y: 0 };
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_int_origin`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `float_origin`
[INFO] [stdout]   --> src/generics.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let float_origin = Point { x: 0.0, y: 0.0 };
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_float_origin`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/io.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let mut input = String::new();
[INFO] [stdout]    |         ----^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `couple`
[INFO] [stdout]   --> src/generics.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let couple = make_pair("male", "female");
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_couple`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `int_origin`
[INFO] [stdout]   --> src/generics.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let int_origin = Point { x: 0, y: 0 };
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_int_origin`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `float_origin`
[INFO] [stdout]   --> src/generics.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let float_origin = Point { x: 0.0, y: 0.0 };
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_float_origin`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/io.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let mut input = String::new();
[INFO] [stdout]    |         ----^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `display_test` is never used
[INFO] [stdout]  --> src/display.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn display_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `List` is never constructed
[INFO] [stdout]  --> src/complicated/list.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct List(Vec<i32>);
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `list_test` is never used
[INFO] [stdout]   --> src/complicated/list.rs:20:4
[INFO] [stdout]    |
[INFO] [stdout] 20 | fn list_test() {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `literal_operator_test` is never used
[INFO] [stdout]  --> src/literals_operators.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn literal_operator_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `array_test` is never used
[INFO] [stdout]  --> src/array.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn array_test() {
[INFO] [stdout]   |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `str_test` is never used
[INFO] [stdout]  --> src/str.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn str_test() {
[INFO] [stdout]   |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `struct_test` is never used
[INFO] [stdout]  --> src/struct.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn struct_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `control_flow_test` is never used
[INFO] [stdout]  --> src/control_flow.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn control_flow_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `if_test` is never used
[INFO] [stdout]  --> src/control_flow.rs:8:4
[INFO] [stdout]   |
[INFO] [stdout] 8 | fn if_test() {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `for_test` is never used
[INFO] [stdout]   --> src/control_flow.rs:14:4
[INFO] [stdout]    |
[INFO] [stdout] 14 | fn for_test() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `while_test` is never used
[INFO] [stdout]   --> src/control_flow.rs:28:4
[INFO] [stdout]    |
[INFO] [stdout] 28 | fn while_test() {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `match_test` is never used
[INFO] [stdout]   --> src/control_flow.rs:40:4
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn match_test() {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `function_test` is never used
[INFO] [stdout]  --> src/function.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn function_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `add_one` is never used
[INFO] [stdout]  --> src/function.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn add_one(x: i32) -> i32 {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `diverges` is never used
[INFO] [stdout]   --> src/function.rs:14:4
[INFO] [stdout]    |
[INFO] [stdout] 14 | fn diverges() -> ! {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `closure` is never used
[INFO] [stdout]   --> src/function.rs:18:4
[INFO] [stdout]    |
[INFO] [stdout] 18 | fn closure() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `high_order_function` is never used
[INFO] [stdout]   --> src/function.rs:33:4
[INFO] [stdout]    |
[INFO] [stdout] 33 | fn high_order_function() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `method_test` is never used
[INFO] [stdout]  --> src/method.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn method_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new` and `area` are never used
[INFO] [stdout]   --> src/method.rs:9:12
[INFO] [stdout]    |
[INFO] [stdout] 8  |     impl Circle {
[INFO] [stdout]    |     ----------- associated items in this implementation
[INFO] [stdout] 9  |         fn new(x: f64, y: f64, radius: f64) -> Circle {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 17 |         fn area(&self) -> f64 {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `trait_test` is never used
[INFO] [stdout]  --> src/trait.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn trait_test() {
[INFO] [stdout]   |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `trait_with_generics` is never used
[INFO] [stdout]   --> src/trait.rs:55:4
[INFO] [stdout]    |
[INFO] [stdout] 55 | fn trait_with_generics() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `inheritance_test` is never used
[INFO] [stdout]  --> src/inheritance.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn inheritance_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `generics_test` is never used
[INFO] [stdout]  --> src/generics.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn generics_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `generics` is never used
[INFO] [stdout]  --> src/generics.rs:6:4
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn generics() {
[INFO] [stdout]   |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `polymorphism` is never used
[INFO] [stdout]   --> src/generics.rs:30:4
[INFO] [stdout]    |
[INFO] [stdout] 30 | fn polymorphism() {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `add_test` is never used
[INFO] [stdout]   --> src/generics.rs:58:4
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn add_test() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `io_test` is never used
[INFO] [stdout]  --> src/io.rs:6:4
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn io_test() {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `std_in` is never used
[INFO] [stdout]   --> src/io.rs:12:4
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn std_in() {
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `file_out` is never used
[INFO] [stdout]   --> src/io.rs:29:4
[INFO] [stdout]    |
[INFO] [stdout] 29 | fn file_out() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `file_out_example2` is never used
[INFO] [stdout]   --> src/io.rs:45:4
[INFO] [stdout]    |
[INFO] [stdout] 45 | fn file_out_example2() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `file_in` is never used
[INFO] [stdout]   --> src/io.rs:51:4
[INFO] [stdout]    |
[INFO] [stdout] 51 | fn file_in() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Stack` is never constructed
[INFO] [stdout]  --> src/problems/verify_closable.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct Stack {
[INFO] [stdout]   |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: static `LEFT_CHARS` is never used
[INFO] [stdout]  --> src/problems/verify_closable.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | static LEFT_CHARS: &'static str = "({[";
[INFO] [stdout]   |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `push`, `pop`, and `print` are never used
[INFO] [stdout]   --> src/problems/verify_closable.rs:8:8
[INFO] [stdout]    |
[INFO] [stdout] 7  | impl Stack {
[INFO] [stdout]    | ---------- associated items in this implementation
[INFO] [stdout] 8  |     fn new() -> Stack {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] ...
[INFO] [stdout] 14 |     fn push(&mut self, s: String) -> bool {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 30 |     fn pop(&mut self) -> String {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] ...
[INFO] [stdout] 40 |     fn print(&self) {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `verify_closable_test` is never used
[INFO] [stdout]   --> src/problems/verify_closable.rs:49:4
[INFO] [stdout]    |
[INFO] [stdout] 49 | fn verify_closable_test() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `verify_closable` is never used
[INFO] [stdout]   --> src/problems/verify_closable.rs:61:4
[INFO] [stdout]    |
[INFO] [stdout] 61 | fn verify_closable(input_str: &str) -> bool {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `examples` is never used
[INFO] [stdout]   --> src/main.rs:25:4
[INFO] [stdout]    |
[INFO] [stdout] 25 | fn examples() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `display_test` is never used
[INFO] [stdout]  --> src/display.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn display_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `List` is never constructed
[INFO] [stdout]  --> src/complicated/list.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct List(Vec<i32>);
[INFO] [stdout]   |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `list_test` is never used
[INFO] [stdout]   --> src/complicated/list.rs:20:4
[INFO] [stdout]    |
[INFO] [stdout] 20 | fn list_test() {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `literal_operator_test` is never used
[INFO] [stdout]  --> src/literals_operators.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn literal_operator_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `array_test` is never used
[INFO] [stdout]  --> src/array.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn array_test() {
[INFO] [stdout]   |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `str_test` is never used
[INFO] [stdout]  --> src/str.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn str_test() {
[INFO] [stdout]   |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `struct_test` is never used
[INFO] [stdout]  --> src/struct.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn struct_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `control_flow_test` is never used
[INFO] [stdout]  --> src/control_flow.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn control_flow_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `if_test` is never used
[INFO] [stdout]  --> src/control_flow.rs:8:4
[INFO] [stdout]   |
[INFO] [stdout] 8 | fn if_test() {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `for_test` is never used
[INFO] [stdout]   --> src/control_flow.rs:14:4
[INFO] [stdout]    |
[INFO] [stdout] 14 | fn for_test() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `while_test` is never used
[INFO] [stdout]   --> src/control_flow.rs:28:4
[INFO] [stdout]    |
[INFO] [stdout] 28 | fn while_test() {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `match_test` is never used
[INFO] [stdout]   --> src/control_flow.rs:40:4
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn match_test() {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `function_test` is never used
[INFO] [stdout]  --> src/function.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn function_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `add_one` is never used
[INFO] [stdout]  --> src/function.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn add_one(x: i32) -> i32 {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `diverges` is never used
[INFO] [stdout]   --> src/function.rs:14:4
[INFO] [stdout]    |
[INFO] [stdout] 14 | fn diverges() -> ! {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `closure` is never used
[INFO] [stdout]   --> src/function.rs:18:4
[INFO] [stdout]    |
[INFO] [stdout] 18 | fn closure() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `high_order_function` is never used
[INFO] [stdout]   --> src/function.rs:33:4
[INFO] [stdout]    |
[INFO] [stdout] 33 | fn high_order_function() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `method_test` is never used
[INFO] [stdout]  --> src/method.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn method_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new` and `area` are never used
[INFO] [stdout]   --> src/method.rs:9:12
[INFO] [stdout]    |
[INFO] [stdout] 8  |     impl Circle {
[INFO] [stdout]    |     ----------- associated items in this implementation
[INFO] [stdout] 9  |         fn new(x: f64, y: f64, radius: f64) -> Circle {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 17 |         fn area(&self) -> f64 {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `clone` that must be used
[INFO] [stdout]   --> src/trait.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |         s.clone();
[INFO] [stdout]    |         ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 59 |         let _ = s.clone();
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `trait_test` is never used
[INFO] [stdout]  --> src/trait.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn trait_test() {
[INFO] [stdout]   |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `clone` that must be used
[INFO] [stdout]   --> src/trait.rs:64:9
[INFO] [stdout]    |
[INFO] [stdout] 64 |         s.clone();
[INFO] [stdout]    |         ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 64 |         let _ = s.clone();
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `trait_with_generics` is never used
[INFO] [stdout]   --> src/trait.rs:55:4
[INFO] [stdout]    |
[INFO] [stdout] 55 | fn trait_with_generics() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `inheritance_test` is never used
[INFO] [stdout]  --> src/inheritance.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn inheritance_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `generics_test` is never used
[INFO] [stdout]  --> src/generics.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn generics_test() {
[INFO] [stdout]   |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `generics` is never used
[INFO] [stdout]  --> src/generics.rs:6:4
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn generics() {
[INFO] [stdout]   |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `polymorphism` is never used
[INFO] [stdout]   --> src/generics.rs:30:4
[INFO] [stdout]    |
[INFO] [stdout] 30 | fn polymorphism() {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `add_test` is never used
[INFO] [stdout]   --> src/generics.rs:58:4
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn add_test() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `io_test` is never used
[INFO] [stdout]  --> src/io.rs:6:4
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn io_test() {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `std_in` is never used
[INFO] [stdout]   --> src/io.rs:12:4
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn std_in() {
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `file_out` is never used
[INFO] [stdout]   --> src/io.rs:29:4
[INFO] [stdout]    |
[INFO] [stdout] 29 | fn file_out() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `file_out_example2` is never used
[INFO] [stdout]   --> src/io.rs:45:4
[INFO] [stdout]    |
[INFO] [stdout] 45 | fn file_out_example2() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `file_in` is never used
[INFO] [stdout]   --> src/io.rs:51:4
[INFO] [stdout]    |
[INFO] [stdout] 51 | fn file_in() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Stack` is never constructed
[INFO] [stdout]  --> src/problems/verify_closable.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct Stack {
[INFO] [stdout]   |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: static `LEFT_CHARS` is never used
[INFO] [stdout]  --> src/problems/verify_closable.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | static LEFT_CHARS: &'static str = "({[";
[INFO] [stdout]   |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `push`, `pop`, and `print` are never used
[INFO] [stdout]   --> src/problems/verify_closable.rs:8:8
[INFO] [stdout]    |
[INFO] [stdout] 7  | impl Stack {
[INFO] [stdout]    | ---------- associated items in this implementation
[INFO] [stdout] 8  |     fn new() -> Stack {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] ...
[INFO] [stdout] 14 |     fn push(&mut self, s: String) -> bool {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 30 |     fn pop(&mut self) -> String {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] ...
[INFO] [stdout] 40 |     fn print(&self) {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `verify_closable_test` is never used
[INFO] [stdout]   --> src/problems/verify_closable.rs:49:4
[INFO] [stdout]    |
[INFO] [stdout] 49 | fn verify_closable_test() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `verify_closable` is never used
[INFO] [stdout]   --> src/problems/verify_closable.rs:61:4
[INFO] [stdout]    |
[INFO] [stdout] 61 | fn verify_closable(input_str: &str) -> bool {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `examples` is never used
[INFO] [stdout]   --> src/main.rs:25:4
[INFO] [stdout]    |
[INFO] [stdout] 25 | fn examples() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `clone` that must be used
[INFO] [stdout]   --> src/trait.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |         s.clone();
[INFO] [stdout]    |         ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 59 |         let _ = s.clone();
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `clone` that must be used
[INFO] [stdout]   --> src/trait.rs:64:9
[INFO] [stdout]    |
[INFO] [stdout] 64 |         s.clone();
[INFO] [stdout]    |         ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 64 |         let _ = s.clone();
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 65 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 65 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.14s
[INFO] running `Command { std: "docker" "inspect" "76f88463996856394fdd080b6e0449447ca04d4e53238bb3e18f8ed917293786", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "76f88463996856394fdd080b6e0449447ca04d4e53238bb3e18f8ed917293786", kill_on_drop: false }`
[INFO] [stdout] 76f88463996856394fdd080b6e0449447ca04d4e53238bb3e18f8ed917293786