[INFO] cloning repository https://github.com/Fox-Demo/rust-demo
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Fox-Demo/rust-demo" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FFox-Demo%2Frust-demo", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FFox-Demo%2Frust-demo'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3f3fc6e5c2418ab82a020e675e060eba5bb02b03
[INFO] checking Fox-Demo/rust-demo against master#507271bc119683008ec719ecee48814e8ac86c65 for pr-146440
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FFox-Demo%2Frust-demo" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/Fox-Demo/rust-demo
[INFO] finished tweaking git repo https://github.com/Fox-Demo/rust-demo
[INFO] tweaked toml for git repo https://github.com/Fox-Demo/rust-demo written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/Fox-Demo/rust-demo on toolchain 507271bc119683008ec719ecee48814e8ac86c65
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+507271bc119683008ec719ecee48814e8ac86c65" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/Fox-Demo/rust-demo 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" "+507271bc119683008ec719ecee48814e8ac86c65" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+507271bc119683008ec719ecee48814e8ac86c65" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f695a659bcedddc9c1a11fe547f2cdfed6976f07e91b489be4fd8841681c9451
[INFO] running `Command { std: "docker" "start" "-a" "f695a659bcedddc9c1a11fe547f2cdfed6976f07e91b489be4fd8841681c9451", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f695a659bcedddc9c1a11fe547f2cdfed6976f07e91b489be4fd8841681c9451", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f695a659bcedddc9c1a11fe547f2cdfed6976f07e91b489be4fd8841681c9451", kill_on_drop: false }`
[INFO] [stdout] f695a659bcedddc9c1a11fe547f2cdfed6976f07e91b489be4fd8841681c9451
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+507271bc119683008ec719ecee48814e8ac86c65" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 92583e613f7031b5671ae581656715a62efb379f09346776f857284047cb7d04
[INFO] running `Command { std: "docker" "start" "-a" "92583e613f7031b5671ae581656715a62efb379f09346776f857284047cb7d04", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_demo v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking Concurrency v0.1.0 (/opt/rustwide/workdir/Concurrency)
[INFO] [stderr]     Checking Box v0.1.0 (/opt/rustwide/workdir/Box)
[INFO] [stdout] warning: unused variable: `r5`
[INFO] [stdout]   --> Box/src/leak.rs:77:9
[INFO] [stdout]    |
[INFO] [stdout] 77 |     let r5 = Rc::clone(&r1); // strong count 2
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r5`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r6`
[INFO] [stdout]   --> Box/src/leak.rs:78:9
[INFO] [stdout]    |
[INFO] [stdout] 78 |     let r6 = r4.upgrade(); // strong count 3
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r6`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> Box/src/rc.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let b = Cons(3, Rc::clone(&a)); // count 2
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> Box/src/rc.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let c = Cons(4, Rc::clone(&a)); // count 3
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `CustomSP` is never constructed
[INFO] [stdout]  --> Box/src/drop.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct CustomSP {
[INFO] [stdout]   |        ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `ref_cycle` is never used
[INFO] [stdout]  --> Box/src/leak.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub fn ref_cycle() {
[INFO] [stdout]   |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `tail` is never used
[INFO] [stdout]   --> Box/src/leak.rs:14:12
[INFO] [stdout]    |
[INFO] [stdout] 13 |     impl List {
[INFO] [stdout]    |     --------- method in this implementation
[INFO] [stdout] 14 |         fn tail(&self) -> Option<&RefCell<Rc<List>>> {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `simple_node` is never used
[INFO] [stdout]   --> Box/src/leak.rs:49:4
[INFO] [stdout]    |
[INFO] [stdout] 49 | fn simple_node() {
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `quiz` is never used
[INFO] [stdout]   --> Box/src/leak.rs:70:4
[INFO] [stdout]    |
[INFO] [stdout] 70 | fn quiz() {
[INFO] [stdout]    |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `weak_node` is never used
[INFO] [stdout]   --> Box/src/leak.rs:84:4
[INFO] [stdout]    |
[INFO] [stdout] 84 | fn weak_node() {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `List` is never used
[INFO] [stdout]  --> Box/src/rc.rs:6:10
[INFO] [stdout]   |
[INFO] [stdout] 6 | pub enum List {
[INFO] [stdout]   |          ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `rc_list` is never used
[INFO] [stdout]   --> Box/src/rc.rs:11:4
[INFO] [stdout]    |
[INFO] [stdout] 11 | fn rc_list() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Messenger` is never used
[INFO] [stdout]  --> Box/src/refcell.rs:1:11
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub trait Messenger {
[INFO] [stdout]   |           ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `LimitTracker` is never constructed
[INFO] [stdout]  --> Box/src/refcell.rs:5:12
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub 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]   --> Box/src/refcell.rs:15:12
[INFO] [stdout]    |
[INFO] [stdout] 11 | / impl<'a, T> LimitTracker<'a, T>
[INFO] [stdout] 12 | | where
[INFO] [stdout] 13 | |     T: Messenger,
[INFO] [stdout]    | |_________________- associated items in this implementation
[INFO] [stdout] 14 |   {
[INFO] [stdout] 15 |       pub fn new(messenger: &'a T, max: usize) -> LimitTracker<'a, T> {
[INFO] [stdout]    |              ^^^
[INFO] [stdout] ...
[INFO] [stdout] 23 |       pub fn set_value(&mut self, value: usize) {
[INFO] [stdout]    |              ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: crate `Box` should have a snake case name
[INFO] [stdout]   |
[INFO] [stdout]   = help: convert the identifier to snake case: `box`
[INFO] [stdout]   = note: `#[warn(non_snake_case)]` (part of `#[warn(nonstandard_style)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: crate `Concurrency` should have a snake case name
[INFO] [stdout]   |
[INFO] [stdout]   = help: convert the identifier to snake case: `concurrency`
[INFO] [stdout]   = note: `#[warn(non_snake_case)]` (part of `#[warn(nonstandard_style)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `cloner`
[INFO] [stdout]   --> src/book/closure.rs:48:9
[INFO] [stdout]    |
[INFO] [stdout] 48 |     let cloner = make_a_cloner(s_ref);
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_cloner`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `cloner`
[INFO] [stdout]   --> src/book/closure.rs:48:9
[INFO] [stdout]    |
[INFO] [stdout] 48 |     let cloner = make_a_cloner(s_ref);
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_cloner`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `get_file1`
[INFO] [stdout]   --> src/book/error.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let get_file1 = match result {
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_get_file1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `get_file2`
[INFO] [stdout]   --> src/book/error.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let get_file2 = match result {
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_get_file2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `get_file3`
[INFO] [stdout]   --> src/book/error.rs:60:9
[INFO] [stdout]    |
[INFO] [stdout] 60 |     let get_file3 = File::open("hello.txt").expect("hello.txt must be in project");
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_get_file3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `invalid_guess`
[INFO] [stdout]   --> src/book/error.rs:91:9
[INFO] [stdout]    |
[INFO] [stdout] 91 |     let invalid_guess = Guess::new(-1);
[INFO] [stdout]    |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_invalid_guess`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v2`
[INFO] [stdout]   --> src/book/iterator.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let v2: Vec<_> = v1.iter().map(|x| x + 1).collect(); // consume iterator by `collect`
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_v2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `get_file1`
[INFO] [stdout]   --> src/book/error.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let get_file1 = match result {
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_get_file1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `get_file2`
[INFO] [stdout]   --> src/book/error.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let get_file2 = match result {
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_get_file2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `black`
[INFO] [stdout]   --> src/book/structs.rs:55:9
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let black = ColorTuple(0, 0, 0);
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_black`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `get_file3`
[INFO] [stdout]   --> src/book/error.rs:60:9
[INFO] [stdout]    |
[INFO] [stdout] 60 |     let get_file3 = File::open("hello.txt").expect("hello.txt must be in project");
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_get_file3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `invalid_guess`
[INFO] [stdout]   --> src/book/error.rs:91:9
[INFO] [stdout]    |
[INFO] [stdout] 91 |     let invalid_guess = Guess::new(-1);
[INFO] [stdout]    |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_invalid_guess`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/book/structs.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |     let mut user1 = User {
[INFO] [stdout]    |         ----^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user2`
[INFO] [stdout]   --> src/book/structs.rs:66:9
[INFO] [stdout]    |
[INFO] [stdout] 66 |     let user2 = User {
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/book/structs.rs:84:9
[INFO] [stdout]    |
[INFO] [stdout] 84 |     let x = &mut p.x;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v2`
[INFO] [stdout]   --> src/book/iterator.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let v2: Vec<_> = v1.iter().map(|x| x + 1).collect(); // consume iterator by `collect`
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_v2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]  --> src/book/collections.rs:6:11
[INFO] [stdout]   |
[INFO] [stdout] 6 |     Float(f64),
[INFO] [stdout]   |     ----- ^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     field in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `CheatSheet` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]   |
[INFO] [stdout] 6 -     Float(f64),
[INFO] [stdout] 6 +     Float(()),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]  --> src/book/collections.rs:7:10
[INFO] [stdout]   |
[INFO] [stdout] 7 |     Text(String),
[INFO] [stdout]   |     ---- ^^^^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     field in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `CheatSheet` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]   |
[INFO] [stdout] 7 -     Text(String),
[INFO] [stdout] 7 +     Text(()),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `read_username_from_file` is never used
[INFO] [stdout]   --> src/book/error.rs:63:4
[INFO] [stdout]    |
[INFO] [stdout] 63 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `y` is never read
[INFO] [stdout]  --> src/book/generic.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct Point<T> {
[INFO] [stdout]   |        ----- field in this struct
[INFO] [stdout] 2 |     x: T,
[INFO] [stdout] 3 |     y: T,
[INFO] [stdout]   |     ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `max_num` is never used
[INFO] [stdout]  --> src/book/lifetime.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn max_num<'a>(x: &'a i32, y: &'a i32) -> &'a i32 {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `User` is never constructed
[INFO] [stdout]   --> src/book/structs.rs:43:8
[INFO] [stdout]    |
[INFO] [stdout] 43 | struct User {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `ColorTuple` is never constructed
[INFO] [stdout]   --> src/book/structs.rs:50:8
[INFO] [stdout]    |
[INFO] [stdout] 50 | struct ColorTuple(i32, i32, i32);
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `UnitStruct` is never constructed
[INFO] [stdout]   --> src/book/structs.rs:52:8
[INFO] [stdout]    |
[INFO] [stdout] 52 | struct UnitStruct; //Unit-Like structs
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `create_color` is never used
[INFO] [stdout]   --> src/book/structs.rs:54:4
[INFO] [stdout]    |
[INFO] [stdout] 54 | fn create_color() {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `create_user` is never used
[INFO] [stdout]   --> src/book/structs.rs:58:4
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn create_user() {
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `borrow_struct` is never used
[INFO] [stdout]   --> src/book/structs.rs:72:4
[INFO] [stdout]    |
[INFO] [stdout] 72 | fn borrow_struct() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `self_rect` is never used
[INFO] [stdout]   --> src/book/structs.rs:90:4
[INFO] [stdout]    |
[INFO] [stdout] 90 | fn self_rect() {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `max` and `set_to_max` are never used
[INFO] [stdout]    --> src/book/structs.rs:97:12
[INFO] [stdout]     |
[INFO] [stdout]  96 |     impl Rectangle {
[INFO] [stdout]     |     -------------- methods in this implementation
[INFO] [stdout]  97 |         fn max(&self, other: Self) -> Self {
[INFO] [stdout]     |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 105 |         fn set_to_max(&mut self, other: Rectangle) {
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify2` is never used
[INFO] [stdout]   --> src/book/traits.rs:71:4
[INFO] [stdout]    |
[INFO] [stdout] 71 | fn notify2<T>(item: &T)
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `returns_summarizable` is never used
[INFO] [stdout]   --> src/book/traits.rs:78:4
[INFO] [stdout]    |
[INFO] [stdout] 78 | fn returns_summarizable(switch: bool) -> impl Summary {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `black`
[INFO] [stdout]   --> src/book/structs.rs:55:9
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let black = ColorTuple(0, 0, 0);
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_black`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/book/structs.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |     let mut user1 = User {
[INFO] [stdout]    |         ----^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user2`
[INFO] [stdout]   --> src/book/structs.rs:66:9
[INFO] [stdout]    |
[INFO] [stdout] 66 |     let user2 = User {
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/book/structs.rs:84:9
[INFO] [stdout]    |
[INFO] [stdout] 84 |     let x = &mut p.x;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]  --> src/book/collections.rs:6:11
[INFO] [stdout]   |
[INFO] [stdout] 6 |     Float(f64),
[INFO] [stdout]   |     ----- ^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     field in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `CheatSheet` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]   |
[INFO] [stdout] 6 -     Float(f64),
[INFO] [stdout] 6 +     Float(()),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]  --> src/book/collections.rs:7:10
[INFO] [stdout]   |
[INFO] [stdout] 7 |     Text(String),
[INFO] [stdout]   |     ---- ^^^^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     field in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `CheatSheet` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]   |
[INFO] [stdout] 7 -     Text(String),
[INFO] [stdout] 7 +     Text(()),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `read_username_from_file` is never used
[INFO] [stdout]   --> src/book/error.rs:63:4
[INFO] [stdout]    |
[INFO] [stdout] 63 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `y` is never read
[INFO] [stdout]  --> src/book/generic.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct Point<T> {
[INFO] [stdout]   |        ----- field in this struct
[INFO] [stdout] 2 |     x: T,
[INFO] [stdout] 3 |     y: T,
[INFO] [stdout]   |     ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `filters_by_size` is never used
[INFO] [stdout]   --> src/book/iterator.rs:32:8
[INFO] [stdout]    |
[INFO] [stdout] 32 |     fn filters_by_size() {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `max_num` is never used
[INFO] [stdout]  --> src/book/lifetime.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn max_num<'a>(x: &'a i32, y: &'a i32) -> &'a i32 {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `User` is never constructed
[INFO] [stdout]   --> src/book/structs.rs:43:8
[INFO] [stdout]    |
[INFO] [stdout] 43 | struct User {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `ColorTuple` is never constructed
[INFO] [stdout]   --> src/book/structs.rs:50:8
[INFO] [stdout]    |
[INFO] [stdout] 50 | struct ColorTuple(i32, i32, i32);
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `UnitStruct` is never constructed
[INFO] [stdout]   --> src/book/structs.rs:52:8
[INFO] [stdout]    |
[INFO] [stdout] 52 | struct UnitStruct; //Unit-Like structs
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `create_color` is never used
[INFO] [stdout]   --> src/book/structs.rs:54:4
[INFO] [stdout]    |
[INFO] [stdout] 54 | fn create_color() {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `create_user` is never used
[INFO] [stdout]   --> src/book/structs.rs:58:4
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn create_user() {
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `borrow_struct` is never used
[INFO] [stdout]   --> src/book/structs.rs:72:4
[INFO] [stdout]    |
[INFO] [stdout] 72 | fn borrow_struct() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `self_rect` is never used
[INFO] [stdout]   --> src/book/structs.rs:90:4
[INFO] [stdout]    |
[INFO] [stdout] 90 | fn self_rect() {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `max` and `set_to_max` are never used
[INFO] [stdout]    --> src/book/structs.rs:97:12
[INFO] [stdout]     |
[INFO] [stdout]  96 |     impl Rectangle {
[INFO] [stdout]     |     -------------- methods in this implementation
[INFO] [stdout]  97 |         fn max(&self, other: Self) -> Self {
[INFO] [stdout]     |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 105 |         fn set_to_max(&mut self, other: Rectangle) {
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify2` is never used
[INFO] [stdout]   --> src/book/traits.rs:71:4
[INFO] [stdout]    |
[INFO] [stdout] 71 | fn notify2<T>(item: &T)
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `returns_summarizable` is never used
[INFO] [stdout]   --> src/book/traits.rs:78:4
[INFO] [stdout]    |
[INFO] [stdout] 78 | fn returns_summarizable(switch: bool) -> impl Summary {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `rust_demo::book::closure`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use rust_demo::book::closure;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `rust_demo::book::closure`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use rust_demo::book::closure;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r5`
[INFO] [stdout]   --> Box/src/leak.rs:77:9
[INFO] [stdout]    |
[INFO] [stdout] 77 |     let r5 = Rc::clone(&r1); // strong count 2
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r5`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r6`
[INFO] [stdout]   --> Box/src/leak.rs:78:9
[INFO] [stdout]    |
[INFO] [stdout] 78 |     let r6 = r4.upgrade(); // strong count 3
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r6`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> Box/src/rc.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let b = Cons(3, Rc::clone(&a)); // count 2
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> Box/src/rc.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let c = Cons(4, Rc::clone(&a)); // count 3
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `list`
[INFO] [stdout]   --> Box/src/lib.rs:65:13
[INFO] [stdout]    |
[INFO] [stdout] 65 |         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] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]  --> Box/src/leak.rs:7:14
[INFO] [stdout]   |
[INFO] [stdout] 7 |         Cons(i32, RefCell<Rc<List>>),
[INFO] [stdout]   |         ---- ^^^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         field in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]   |
[INFO] [stdout] 7 -         Cons(i32, RefCell<Rc<List>>),
[INFO] [stdout] 7 +         Cons((), RefCell<Rc<List>>),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `value` and `children` are never read
[INFO] [stdout]   --> Box/src/leak.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     struct Node {
[INFO] [stdout]    |            ---- fields in this struct
[INFO] [stdout] 52 |         value: i32,
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout] 53 |         children: RefCell<Vec<Rc<Node>>>,
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Node` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]  --> Box/src/rc.rs:7:10
[INFO] [stdout]   |
[INFO] [stdout] 7 |     Cons(i32, Rc<List>),
[INFO] [stdout]   |     ---- ^^^  ^^^^^^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     fields in this variant
[INFO] [stdout]   |
[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] 7 -     Cons(i32, Rc<List>),
[INFO] [stdout] 7 +     Cons((), ()),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [optimized + debuginfo] target(s) in 0.64s
[INFO] running `Command { std: "docker" "inspect" "92583e613f7031b5671ae581656715a62efb379f09346776f857284047cb7d04", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "92583e613f7031b5671ae581656715a62efb379f09346776f857284047cb7d04", kill_on_drop: false }`
[INFO] [stdout] 92583e613f7031b5671ae581656715a62efb379f09346776f857284047cb7d04
