[INFO] cloning repository https://github.com/0xAsten/hello_guessing_game
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/0xAsten/hello_guessing_game" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F0xAsten%2Fhello_guessing_game", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F0xAsten%2Fhello_guessing_game'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f13cba1ebe528327e81b366d37b06794d5303921
[INFO] checking 0xAsten/hello_guessing_game against try#5fee451ebd94296ea05214e819c311e164b30af6 for pr-139042
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F0xAsten%2Fhello_guessing_game" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/0xAsten/hello_guessing_game on toolchain 5fee451ebd94296ea05214e819c311e164b30af6
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+5fee451ebd94296ea05214e819c311e164b30af6" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/0xAsten/hello_guessing_game
[INFO] finished tweaking git repo https://github.com/0xAsten/hello_guessing_game
[INFO] tweaked toml for git repo https://github.com/0xAsten/hello_guessing_game written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/0xAsten/hello_guessing_game 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" "+5fee451ebd94296ea05214e819c311e164b30af6" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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@sha256:4b26683ee3c49f365255c425c23003cbf4366de097804722c29c5bbbee3624d2" "/opt/rustwide/cargo-home/bin/cargo" "+5fee451ebd94296ea05214e819c311e164b30af6" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] dbb96e7b9329e81912cdba9c4d28032d35481520a7116fba7f985685c684a315
[INFO] running `Command { std: "docker" "start" "-a" "dbb96e7b9329e81912cdba9c4d28032d35481520a7116fba7f985685c684a315", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "dbb96e7b9329e81912cdba9c4d28032d35481520a7116fba7f985685c684a315", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dbb96e7b9329e81912cdba9c4d28032d35481520a7116fba7f985685c684a315", kill_on_drop: false }`
[INFO] [stdout] dbb96e7b9329e81912cdba9c4d28032d35481520a7116fba7f985685c684a315
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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@sha256:4b26683ee3c49f365255c425c23003cbf4366de097804722c29c5bbbee3624d2" "/opt/rustwide/cargo-home/bin/cargo" "+5fee451ebd94296ea05214e819c311e164b30af6" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 93062c1171681a21804b2a889680298c6e4c1fa5e13a55d254b10a74ea4bdc82
[INFO] running `Command { std: "docker" "start" "-a" "93062c1171681a21804b2a889680298c6e4c1fa5e13a55d254b10a74ea4bdc82", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.147
[INFO] [stderr]    Compiling rustix v0.38.4
[INFO] [stderr]     Checking getrandom v0.2.10
[INFO] [stderr]     Checking is-terminal v0.4.9
[INFO] [stderr]     Checking colored v2.0.4
[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 hello_guessing_game v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: struct `Counter` is never constructed
[INFO] [stdout]   --> src/bin/iterator/main.rs:54:8
[INFO] [stdout]    |
[INFO] [stdout] 54 | struct Counter {
[INFO] [stdout]    |        ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/bin/iterator/main.rs:59:8
[INFO] [stdout]    |
[INFO] [stdout] 58 | impl Counter {
[INFO] [stdout]    | ------------ associated function in this implementation
[INFO] [stdout] 59 |     fn new() -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/bin/generic_lifetime_annotation/main.rs:40:30
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn longest_2<'a>(x: &'a str, y: &str) -> &'a str {
[INFO] [stdout]    |                              ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `ImportantExcerpt` is never constructed
[INFO] [stdout]  --> src/bin/generic_lifetime_annotation/main.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct ImportantExcerpt<'a> {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `return_part` is never used
[INFO] [stdout]  --> src/bin/generic_lifetime_annotation/main.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 7 | impl<'a> ImportantExcerpt<'a> {
[INFO] [stdout]   | ----------------------------- method in this implementation
[INFO] [stdout] 8 |     fn return_part(&self) -> &str {
[INFO] [stdout]   |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/error_handling/main.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let f = match f {
[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: unused variable: `f`
[INFO] [stdout]   --> src/bin/error_handling/main.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |     let f = File::open("hello.text").unwrap_or_else(|error| {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/error_handling/main.rs:59:13
[INFO] [stdout]    |
[INFO] [stdout] 59 |     let mut f = File::open("hello.txt")?.read_to_string(&mut s)?;
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/error_handling/main.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |     let mut f = File::open("hello.txt")?.read_to_string(&mut s)?;
[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: function `open_file_1` is never used
[INFO] [stdout]  --> src/bin/error_handling/main.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn open_file_1() {
[INFO] [stdout]   |    ^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `read_username_from_file_1` is never used
[INFO] [stdout]   --> src/bin/error_handling/main.rs:34:4
[INFO] [stdout]    |
[INFO] [stdout] 34 | fn read_username_from_file_1() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `read_username_from_file_2` is never used
[INFO] [stdout]   --> src/bin/error_handling/main.rs:48:4
[INFO] [stdout]    |
[INFO] [stdout] 48 | fn read_username_from_file_2() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `read_username_from_file_3` is never used
[INFO] [stdout]   --> src/bin/error_handling/main.rs:57:4
[INFO] [stdout]    |
[INFO] [stdout] 57 | fn read_username_from_file_3() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `list`
[INFO] [stdout]  --> src/bin/smart_pointer/main.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let list = Cons(1, Box::new(Cons(2, Box::new(Cons(3, Box::new(Nil))))));
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_list`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `list`
[INFO] [stdout]  --> src/bin/smart_pointer/main.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let list = Cons(1, Box::new(Cons(2, Box::new(Cons(3, Box::new(Nil))))));
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_list`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Iterator` is never used
[INFO] [stdout]  --> src/bin/advanced_trait/main.rs:3:7
[INFO] [stdout]   |
[INFO] [stdout] 3 | trait Iterator {
[INFO] [stdout]   |       ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]  --> src/bin/smart_pointer/main.rs:2:10
[INFO] [stdout]   |
[INFO] [stdout] 2 |     Cons(i32, Box<List>),
[INFO] [stdout]   |     ---- ^^^  ^^^^^^^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     fields in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]   |
[INFO] [stdout] 2 -     Cons(i32, Box<List>),
[INFO] [stdout] 2 +     Cons((), ()),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `MyBox` is never constructed
[INFO] [stdout]   --> src/bin/smart_pointer/main.rs:14:8
[INFO] [stdout]    |
[INFO] [stdout] 14 | struct MyBox<T>(T);
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/bin/smart_pointer/main.rs:17:8
[INFO] [stdout]    |
[INFO] [stdout] 16 | impl<T> MyBox<T> {
[INFO] [stdout]    | ---------------- associated function in this implementation
[INFO] [stdout] 17 |     fn new(x: T) -> MyBox<T> {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `use_mybox` is never used
[INFO] [stdout]   --> src/bin/smart_pointer/main.rs:30:4
[INFO] [stdout]    |
[INFO] [stdout] 30 | fn use_mybox() {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `hello` is never used
[INFO] [stdout]   --> src/bin/smart_pointer/main.rs:42:4
[INFO] [stdout]    |
[INFO] [stdout] 42 | fn hello(name: &str) {
[INFO] [stdout]    |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `CustomSmartPointer` is never constructed
[INFO] [stdout]   --> src/bin/smart_pointer/main.rs:48:8
[INFO] [stdout]    |
[INFO] [stdout] 48 | struct CustomSmartPointer {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `drop_before_end` is never used
[INFO] [stdout]   --> src/bin/smart_pointer/main.rs:58:4
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn drop_before_end() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]  --> src/bin/smart_pointer/main.rs:2:10
[INFO] [stdout]   |
[INFO] [stdout] 2 |     Cons(i32, Box<List>),
[INFO] [stdout]   |     ---- ^^^  ^^^^^^^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     fields in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]   |
[INFO] [stdout] 2 -     Cons(i32, Box<List>),
[INFO] [stdout] 2 +     Cons((), ()),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `MyBox` is never constructed
[INFO] [stdout]   --> src/bin/smart_pointer/main.rs:14:8
[INFO] [stdout]    |
[INFO] [stdout] 14 | struct MyBox<T>(T);
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/bin/smart_pointer/main.rs:17:8
[INFO] [stdout]    |
[INFO] [stdout] 16 | impl<T> MyBox<T> {
[INFO] [stdout]    | ---------------- associated function in this implementation
[INFO] [stdout] 17 |     fn new(x: T) -> MyBox<T> {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `use_mybox` is never used
[INFO] [stdout]   --> src/bin/smart_pointer/main.rs:30:4
[INFO] [stdout]    |
[INFO] [stdout] 30 | fn use_mybox() {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `hello` is never used
[INFO] [stdout]   --> src/bin/smart_pointer/main.rs:42:4
[INFO] [stdout]    |
[INFO] [stdout] 42 | fn hello(name: &str) {
[INFO] [stdout]    |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `CustomSmartPointer` is never constructed
[INFO] [stdout]   --> src/bin/smart_pointer/main.rs:48:8
[INFO] [stdout]    |
[INFO] [stdout] 48 | struct CustomSmartPointer {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `drop_before_end` is never used
[INFO] [stdout]   --> src/bin/smart_pointer/main.rs:58:4
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn drop_before_end() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Counter` is never constructed
[INFO] [stdout]  --> src/bin/advanced_trait/main.rs:9:8
[INFO] [stdout]   |
[INFO] [stdout] 9 | struct Counter {}
[INFO] [stdout]   |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Iterator2` is never used
[INFO] [stdout]   --> src/bin/advanced_trait/main.rs:18:7
[INFO] [stdout]    |
[INFO] [stdout] 18 | trait Iterator2<T> {
[INFO] [stdout]    |       ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `OutlinePrint` is never used
[INFO] [stdout]    --> src/bin/advanced_trait/main.rs:130:7
[INFO] [stdout]     |
[INFO] [stdout] 130 | trait OutlinePrint: fmt::Display {}
[INFO] [stdout]     |       ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `vector` is never used
[INFO] [stdout]  --> src/bin/collections/main.rs:6:4
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn vector() {
[INFO] [stdout]   |    ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `string` is never used
[INFO] [stdout]   --> src/bin/collections/main.rs:52:4
[INFO] [stdout]    |
[INFO] [stdout] 52 | fn string() {
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `vector` is never used
[INFO] [stdout]  --> src/bin/collections/main.rs:6:4
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn vector() {
[INFO] [stdout]   |    ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/error_handling/main.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let f = match f {
[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: function `string` is never used
[INFO] [stdout]   --> src/bin/collections/main.rs:52:4
[INFO] [stdout]    |
[INFO] [stdout] 52 | fn string() {
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/error_handling/main.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |     let f = File::open("hello.text").unwrap_or_else(|error| {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item1`
[INFO] [stdout]   --> src/bin/traits/main.rs:40:13
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn notify_3(item1: &impl Summary, item2: &impl Summary) {
[INFO] [stdout]    |             ^^^^^ help: if this is intentional, prefix it with an underscore: `_item1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/error_handling/main.rs:59:13
[INFO] [stdout]    |
[INFO] [stdout] 59 |     let mut f = File::open("hello.txt")?.read_to_string(&mut s)?;
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/error_handling/main.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |     let mut f = File::open("hello.txt")?.read_to_string(&mut s)?;
[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: function `open_file_1` is never used
[INFO] [stdout]  --> src/bin/error_handling/main.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn open_file_1() {
[INFO] [stdout]   |    ^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `read_username_from_file_1` is never used
[INFO] [stdout]   --> src/bin/error_handling/main.rs:34:4
[INFO] [stdout]    |
[INFO] [stdout] 34 | fn read_username_from_file_1() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `read_username_from_file_2` is never used
[INFO] [stdout]   --> src/bin/error_handling/main.rs:48:4
[INFO] [stdout]    |
[INFO] [stdout] 48 | fn read_username_from_file_2() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `read_username_from_file_3` is never used
[INFO] [stdout]   --> src/bin/error_handling/main.rs:57:4
[INFO] [stdout]    |
[INFO] [stdout] 57 | fn read_username_from_file_3() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> src/bin/traits/main.rs:40:35
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn notify_3(item1: &impl Summary, item2: &impl Summary) {
[INFO] [stdout]    |                                   ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item1`
[INFO] [stdout]   --> src/bin/traits/main.rs:44:25
[INFO] [stdout]    |
[INFO] [stdout] 44 | fn notify_4<T: Summary>(item1: &T, item2: &T) {
[INFO] [stdout]    |                         ^^^^^ help: if this is intentional, prefix it with an underscore: `_item1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> src/bin/traits/main.rs:44:36
[INFO] [stdout]    |
[INFO] [stdout] 44 | fn notify_4<T: Summary>(item1: &T, item2: &T) {
[INFO] [stdout]    |                                    ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/bin/traits/main.rs:49:53
[INFO] [stdout]    |
[INFO] [stdout] 49 | fn some_fun_1<T: Display + Clone, U: Clone + Debug>(t: &T, u: &U) {
[INFO] [stdout]    |                                                     ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> src/bin/traits/main.rs:49:60
[INFO] [stdout]    |
[INFO] [stdout] 49 | fn some_fun_1<T: Display + Clone, U: Clone + Debug>(t: &T, u: &U) {
[INFO] [stdout]    |                                                            ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/bin/traits/main.rs:53:21
[INFO] [stdout]    |
[INFO] [stdout] 53 | fn some_fun_2<T, U>(t: &T, u: &U)
[INFO] [stdout]    |                     ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> src/bin/traits/main.rs:53:28
[INFO] [stdout]    |
[INFO] [stdout] 53 | fn some_fun_2<T, U>(t: &T, u: &U)
[INFO] [stdout]    |                            ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `guessing_game` is never used
[INFO] [stdout]   --> src/main.rs:31:4
[INFO] [stdout]    |
[INFO] [stdout] 31 | fn guessing_game() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `headline` is never read
[INFO] [stdout]  --> src/bin/traits/main.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct NewsArticle {
[INFO] [stdout]   |        ----------- field in this struct
[INFO] [stdout] 4 |     author: String,
[INFO] [stdout] 5 |     headline: String,
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Tweet` is never constructed
[INFO] [stdout]  --> src/bin/traits/main.rs:9:8
[INFO] [stdout]   |
[INFO] [stdout] 9 | struct Tweet {
[INFO] [stdout]   |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify_2` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:36:4
[INFO] [stdout]    |
[INFO] [stdout] 36 | fn notify_2<T: Summary>(item: &T) {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify_3` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:40:4
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn notify_3(item1: &impl Summary, item2: &impl Summary) {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify_4` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:44:4
[INFO] [stdout]    |
[INFO] [stdout] 44 | fn notify_4<T: Summary>(item1: &T, item2: &T) {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_fun_1` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:49:4
[INFO] [stdout]    |
[INFO] [stdout] 49 | fn some_fun_1<T: Display + Clone, U: Clone + Debug>(t: &T, u: &U) {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_fun_2` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:53:4
[INFO] [stdout]    |
[INFO] [stdout] 53 | fn some_fun_2<T, U>(t: &T, u: &U)
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `returns_summarizable` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:62:4
[INFO] [stdout]    |
[INFO] [stdout] 62 | fn returns_summarizable() -> impl Summary {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Pair` is never constructed
[INFO] [stdout]   --> src/bin/traits/main.rs:71:8
[INFO] [stdout]    |
[INFO] [stdout] 71 | struct Pair<T> {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:77:8
[INFO] [stdout]    |
[INFO] [stdout] 76 | impl<T> Pair<T> {
[INFO] [stdout]    | --------------- associated function in this implementation
[INFO] [stdout] 77 |     fn new(x: T, y: T) -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `compare` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:83:8
[INFO] [stdout]    |
[INFO] [stdout] 82 | impl<T: Display + PartialOrd> Pair<T> {
[INFO] [stdout]    | ------------------------------------- method in this implementation
[INFO] [stdout] 83 |     fn compare(&self) {
[INFO] [stdout]    |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `cached_result`
[INFO] [stdout]   --> src/bin/closures/main.rs:38:13
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let mut cached_result = Cacher::new(|num| {
[INFO] [stdout]    |             ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_cached_result`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `x` and `y` are never read
[INFO] [stdout]  --> src/bin/generics/main.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | struct Point<T, U> {
[INFO] [stdout]   |        ----- fields in this struct
[INFO] [stdout] 3 |     x: T,
[INFO] [stdout]   |     ^
[INFO] [stdout] 4 |     y: U,
[INFO] [stdout]   |     ^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `Point` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `x` and `mix` are never used
[INFO] [stdout]   --> src/bin/generics/main.rs:8:8
[INFO] [stdout]    |
[INFO] [stdout] 7  | impl<T, U> Point<T, U> {
[INFO] [stdout]    | ---------------------- methods in this implementation
[INFO] [stdout] 8  |     fn x(&self) -> &T {
[INFO] [stdout]    |        ^
[INFO] [stdout] ...
[INFO] [stdout] 12 |     fn mix<V, W>(self, other: Point<V, W>) -> Point<T, W> {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `num`
[INFO] [stdout]   --> src/bin/closures/main.rs:37:21
[INFO] [stdout]    |
[INFO] [stdout] 37 | fn generate_workout(num: u32) {
[INFO] [stdout]    |                     ^^^ help: if this is intentional, prefix it with an underscore: `_num`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/closures/main.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let mut cached_result = Cacher::new(|num| {
[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: struct `Cacher` is never constructed
[INFO] [stdout]  --> src/bin/closures/main.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct Cacher<T>
[INFO] [stdout]   |        ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new` and `value` are never used
[INFO] [stdout]   --> src/bin/closures/main.rs:15:8
[INFO] [stdout]    |
[INFO] [stdout] 11 | / impl<T> Cacher<T>
[INFO] [stdout] 12 | | where
[INFO] [stdout] 13 | |     T: Fn(u32) -> u32,
[INFO] [stdout]    | |______________________- associated items in this implementation
[INFO] [stdout] 14 |   {
[INFO] [stdout] 15 |       fn new(calculation: T) -> Cacher<T> {
[INFO] [stdout]    |          ^^^
[INFO] [stdout] ...
[INFO] [stdout] 22 |       fn value(&mut self, arg: u32) -> u32 {
[INFO] [stdout]    |          ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `generate_workout` is never used
[INFO] [stdout]   --> src/bin/closures/main.rs:37:4
[INFO] [stdout]    |
[INFO] [stdout] 37 | fn generate_workout(num: u32) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `closuer_env` is never used
[INFO] [stdout]   --> src/bin/closures/main.rs:45:4
[INFO] [stdout]    |
[INFO] [stdout] 45 | fn closuer_env() {
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `closuer_env_FnOnce` is never used
[INFO] [stdout]   --> src/bin/closures/main.rs:58:4
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn closuer_env_FnOnce() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `closuer_env_FnOnce` should have a snake case name
[INFO] [stdout]   --> src/bin/closures/main.rs:58:4
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn closuer_env_FnOnce() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^ help: convert the identifier to snake case: `closuer_env_fn_once`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/bin/smart_pointer_rc/main.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let b = Cons(3, Rc::clone(&a)); // doesn't make deep copy of a only increments the reference count of a
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/bin/smart_pointer_rc/main.rs:16:13
[INFO] [stdout]    |
[INFO] [stdout] 16 |         let c = Cons(4, Rc::clone(&a));
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]  --> src/bin/smart_pointer_rc/main.rs:3:10
[INFO] [stdout]   |
[INFO] [stdout] 3 |     Cons(i32, Rc<List>),
[INFO] [stdout]   |     ---- ^^^  ^^^^^^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     fields in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]   |
[INFO] [stdout] 3 -     Cons(i32, Rc<List>),
[INFO] [stdout] 3 +     Cons((), ()),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item1`
[INFO] [stdout]   --> src/bin/traits/main.rs:40:13
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn notify_3(item1: &impl Summary, item2: &impl Summary) {
[INFO] [stdout]    |             ^^^^^ help: if this is intentional, prefix it with an underscore: `_item1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> src/bin/traits/main.rs:40:35
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn notify_3(item1: &impl Summary, item2: &impl Summary) {
[INFO] [stdout]    |                                   ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item1`
[INFO] [stdout]   --> src/bin/traits/main.rs:44:25
[INFO] [stdout]    |
[INFO] [stdout] 44 | fn notify_4<T: Summary>(item1: &T, item2: &T) {
[INFO] [stdout]    |                         ^^^^^ help: if this is intentional, prefix it with an underscore: `_item1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> src/bin/traits/main.rs:44:36
[INFO] [stdout]    |
[INFO] [stdout] 44 | fn notify_4<T: Summary>(item1: &T, item2: &T) {
[INFO] [stdout]    |                                    ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/bin/traits/main.rs:49:53
[INFO] [stdout]    |
[INFO] [stdout] 49 | fn some_fun_1<T: Display + Clone, U: Clone + Debug>(t: &T, u: &U) {
[INFO] [stdout]    |                                                     ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> src/bin/traits/main.rs:49:60
[INFO] [stdout]    |
[INFO] [stdout] 49 | fn some_fun_1<T: Display + Clone, U: Clone + Debug>(t: &T, u: &U) {
[INFO] [stdout]    |                                                            ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/bin/traits/main.rs:53:21
[INFO] [stdout]    |
[INFO] [stdout] 53 | fn some_fun_2<T, U>(t: &T, u: &U)
[INFO] [stdout]    |                     ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> src/bin/traits/main.rs:53:28
[INFO] [stdout]    |
[INFO] [stdout] 53 | fn some_fun_2<T, U>(t: &T, u: &U)
[INFO] [stdout]    |                            ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `headline` is never read
[INFO] [stdout]  --> src/bin/traits/main.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct NewsArticle {
[INFO] [stdout]   |        ----------- field in this struct
[INFO] [stdout] 4 |     author: String,
[INFO] [stdout] 5 |     headline: String,
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Tweet` is never constructed
[INFO] [stdout]  --> src/bin/traits/main.rs:9:8
[INFO] [stdout]   |
[INFO] [stdout] 9 | struct Tweet {
[INFO] [stdout]   |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify_2` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:36:4
[INFO] [stdout]    |
[INFO] [stdout] 36 | fn notify_2<T: Summary>(item: &T) {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify_3` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:40:4
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn notify_3(item1: &impl Summary, item2: &impl Summary) {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify_4` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:44:4
[INFO] [stdout]    |
[INFO] [stdout] 44 | fn notify_4<T: Summary>(item1: &T, item2: &T) {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_fun_1` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:49:4
[INFO] [stdout]    |
[INFO] [stdout] 49 | fn some_fun_1<T: Display + Clone, U: Clone + Debug>(t: &T, u: &U) {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_fun_2` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:53:4
[INFO] [stdout]    |
[INFO] [stdout] 53 | fn some_fun_2<T, U>(t: &T, u: &U)
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `returns_summarizable` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:62:4
[INFO] [stdout]    |
[INFO] [stdout] 62 | fn returns_summarizable() -> impl Summary {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Pair` is never constructed
[INFO] [stdout]   --> src/bin/traits/main.rs:71:8
[INFO] [stdout]    |
[INFO] [stdout] 71 | struct Pair<T> {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:77:8
[INFO] [stdout]    |
[INFO] [stdout] 76 | impl<T> Pair<T> {
[INFO] [stdout]    | --------------- associated function in this implementation
[INFO] [stdout] 77 |     fn new(x: T, y: T) -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `compare` is never used
[INFO] [stdout]   --> src/bin/traits/main.rs:83:8
[INFO] [stdout]    |
[INFO] [stdout] 82 | impl<T: Display + PartialOrd> Pair<T> {
[INFO] [stdout]    | ------------------------------------- method in this implementation
[INFO] [stdout] 83 |     fn compare(&self) {
[INFO] [stdout]    |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/bin/concurrency/main.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |     for i in 0..10 {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `x` and `y` are never read
[INFO] [stdout]  --> src/bin/generics/main.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | struct Point<T, U> {
[INFO] [stdout]   |        ----- fields in this struct
[INFO] [stdout] 3 |     x: T,
[INFO] [stdout]   |     ^
[INFO] [stdout] 4 |     y: U,
[INFO] [stdout]   |     ^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `Point` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `x` and `mix` are never used
[INFO] [stdout]   --> src/bin/generics/main.rs:8:8
[INFO] [stdout]    |
[INFO] [stdout] 7  | impl<T, U> Point<T, U> {
[INFO] [stdout]    | ---------------------- methods in this implementation
[INFO] [stdout] 8  |     fn x(&self) -> &T {
[INFO] [stdout]    |        ^
[INFO] [stdout] ...
[INFO] [stdout] 12 |     fn mix<V, W>(self, other: Point<V, W>) -> Point<T, W> {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/bin/generic_lifetime_annotation/main.rs:40:30
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn longest_2<'a>(x: &'a str, y: &str) -> &'a str {
[INFO] [stdout]    |                              ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `ImportantExcerpt` is never constructed
[INFO] [stdout]  --> src/bin/generic_lifetime_annotation/main.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct ImportantExcerpt<'a> {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `return_part` is never used
[INFO] [stdout]  --> src/bin/generic_lifetime_annotation/main.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 7 | impl<'a> ImportantExcerpt<'a> {
[INFO] [stdout]   | ----------------------------- method in this implementation
[INFO] [stdout] 8 |     fn return_part(&self) -> &str {
[INFO] [stdout]   |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Iterator` is never used
[INFO] [stdout]  --> src/bin/advanced_trait/main.rs:3:7
[INFO] [stdout]   |
[INFO] [stdout] 3 | trait Iterator {
[INFO] [stdout]   |       ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Counter` is never constructed
[INFO] [stdout]  --> src/bin/advanced_trait/main.rs:9:8
[INFO] [stdout]   |
[INFO] [stdout] 9 | struct Counter {}
[INFO] [stdout]   |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Iterator2` is never used
[INFO] [stdout]   --> src/bin/advanced_trait/main.rs:18:7
[INFO] [stdout]    |
[INFO] [stdout] 18 | trait Iterator2<T> {
[INFO] [stdout]    |       ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `OutlinePrint` is never used
[INFO] [stdout]    --> src/bin/advanced_trait/main.rs:130:7
[INFO] [stdout]     |
[INFO] [stdout] 130 | trait OutlinePrint: fmt::Display {}
[INFO] [stdout]     |       ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/bin/smart_pointer_rc/main.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let b = Cons(3, Rc::clone(&a)); // doesn't make deep copy of a only increments the reference count of a
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/bin/smart_pointer_rc/main.rs:16:13
[INFO] [stdout]    |
[INFO] [stdout] 16 |         let c = Cons(4, Rc::clone(&a));
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]  --> src/bin/smart_pointer_rc/main.rs:3:10
[INFO] [stdout]   |
[INFO] [stdout] 3 |     Cons(i32, Rc<List>),
[INFO] [stdout]   |     ---- ^^^  ^^^^^^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     fields in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]   |
[INFO] [stdout] 3 -     Cons(i32, Rc<List>),
[INFO] [stdout] 3 +     Cons((), ()),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Messenger` is never used
[INFO] [stdout]   --> src/bin/smart_pointer_rc/main.rs:23:7
[INFO] [stdout]    |
[INFO] [stdout] 23 | trait Messenger {
[INFO] [stdout]    |       ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `LimitTracker` is never constructed
[INFO] [stdout]   --> src/bin/smart_pointer_rc/main.rs:27:8
[INFO] [stdout]    |
[INFO] [stdout] 27 | struct LimitTracker<'a, T: Messenger> {
[INFO] [stdout]    |        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new` and `set_value` are never used
[INFO] [stdout]   --> src/bin/smart_pointer_rc/main.rs:37:8
[INFO] [stdout]    |
[INFO] [stdout] 33 | / impl<'a, T> LimitTracker<'a, T>
[INFO] [stdout] 34 | | where
[INFO] [stdout] 35 | |     T: Messenger,
[INFO] [stdout]    | |_________________- associated items in this implementation
[INFO] [stdout] 36 |   {
[INFO] [stdout] 37 |       fn new(messenger: &T, max: usize) -> LimitTracker<T> {
[INFO] [stdout]    |          ^^^
[INFO] [stdout] ...
[INFO] [stdout] 45 |       fn set_value(&mut self, value: usize) {
[INFO] [stdout]    |          ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `cached_result`
[INFO] [stdout]   --> src/bin/closures/main.rs:38:13
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let mut cached_result = Cacher::new(|num| {
[INFO] [stdout]    |             ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_cached_result`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `num`
[INFO] [stdout]   --> src/bin/closures/main.rs:37:21
[INFO] [stdout]    |
[INFO] [stdout] 37 | fn generate_workout(num: u32) {
[INFO] [stdout]    |                     ^^^ help: if this is intentional, prefix it with an underscore: `_num`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/closures/main.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let mut cached_result = Cacher::new(|num| {
[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: struct `Cacher` is never constructed
[INFO] [stdout]  --> src/bin/closures/main.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct Cacher<T>
[INFO] [stdout]   |        ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new` and `value` are never used
[INFO] [stdout]   --> src/bin/closures/main.rs:15:8
[INFO] [stdout]    |
[INFO] [stdout] 11 | / impl<T> Cacher<T>
[INFO] [stdout] 12 | | where
[INFO] [stdout] 13 | |     T: Fn(u32) -> u32,
[INFO] [stdout]    | |______________________- associated items in this implementation
[INFO] [stdout] 14 |   {
[INFO] [stdout] 15 |       fn new(calculation: T) -> Cacher<T> {
[INFO] [stdout]    |          ^^^
[INFO] [stdout] ...
[INFO] [stdout] 22 |       fn value(&mut self, arg: u32) -> u32 {
[INFO] [stdout]    |          ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `generate_workout` is never used
[INFO] [stdout]   --> src/bin/closures/main.rs:37:4
[INFO] [stdout]    |
[INFO] [stdout] 37 | fn generate_workout(num: u32) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `closuer_env` is never used
[INFO] [stdout]   --> src/bin/closures/main.rs:45:4
[INFO] [stdout]    |
[INFO] [stdout] 45 | fn closuer_env() {
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `closuer_env_FnOnce` is never used
[INFO] [stdout]   --> src/bin/closures/main.rs:58:4
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn closuer_env_FnOnce() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `closuer_env_FnOnce` should have a snake case name
[INFO] [stdout]   --> src/bin/closures/main.rs:58:4
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn closuer_env_FnOnce() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^ help: convert the identifier to snake case: `closuer_env_fn_once`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `guessing_game` is never used
[INFO] [stdout]   --> src/main.rs:31:4
[INFO] [stdout]    |
[INFO] [stdout] 31 | fn guessing_game() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/bin/concurrency/main.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |     for i in 0..10 {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 3.67s
[INFO] running `Command { std: "docker" "inspect" "93062c1171681a21804b2a889680298c6e4c1fa5e13a55d254b10a74ea4bdc82", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "93062c1171681a21804b2a889680298c6e4c1fa5e13a55d254b10a74ea4bdc82", kill_on_drop: false }`
[INFO] [stdout] 93062c1171681a21804b2a889680298c6e4c1fa5e13a55d254b10a74ea4bdc82
