[INFO] cloning repository https://github.com/HillBamboo/learn_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/HillBamboo/learn_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FHillBamboo%2Flearn_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FHillBamboo%2Flearn_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f772f033dcf258227431aecd75d2c04f01f5746c
[INFO] testing HillBamboo/learn_rust against 1.90.0 for beta-1.91-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FHillBamboo%2Flearn_rust" "/workspace/builds/worker-5-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/HillBamboo/learn_rust
[INFO] finished tweaking git repo https://github.com/HillBamboo/learn_rust
[INFO] tweaked toml for git repo https://github.com/HillBamboo/learn_rust written to /workspace/builds/worker-5-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/HillBamboo/learn_rust on toolchain 1.90.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/HillBamboo/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" "+1.90.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8307b32a77f0e9950309e598a6829e2d6109c130447472db1e068ef146ffa001
[INFO] running `Command { std: "docker" "start" "-a" "8307b32a77f0e9950309e598a6829e2d6109c130447472db1e068ef146ffa001", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8307b32a77f0e9950309e598a6829e2d6109c130447472db1e068ef146ffa001", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8307b32a77f0e9950309e598a6829e2d6109c130447472db1e068ef146ffa001", kill_on_drop: false }`
[INFO] [stdout] 8307b32a77f0e9950309e598a6829e2d6109c130447472db1e068ef146ffa001
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1ad8c37d0b4d1a52295cf0126eee0deb03e3135a4db24f27608d20226582e0a9
[INFO] running `Command { std: "docker" "start" "-a" "1ad8c37d0b4d1a52295cf0126eee0deb03e3135a4db24f27608d20226582e0a9", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.66
[INFO] [stderr]    Compiling rand v0.4.6
[INFO] [stderr]    Compiling rand v0.3.23
[INFO] [stderr]    Compiling learn_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> src/rust_book/ch4_ownership.rs:28:57
[INFO] [stdout]    |
[INFO] [stdout] 28 |     fn take_ownership(s : String) { println!("{}", s); };
[INFO] [stdout]    |                                                         ^ help: remove this semicolon
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(redundant_semicolons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> src/rust_book/ch4_ownership.rs:36:6
[INFO] [stdout]    |
[INFO] [stdout] 36 |     };
[INFO] [stdout]    |      ^ help: remove this semicolon
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `HashSet` and `VecDeque`
[INFO] [stdout]  --> src/rust_book/ch8_collections.rs:2:33
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::collections::{HashMap, HashSet, VecDeque};
[INFO] [stdout]   |                                 ^^^^^^^  ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::fs`
[INFO] [stdout]   --> src/rust_book/ch9_error_handling.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 | use std::fs;
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io`
[INFO] [stdout]   --> src/main.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | use std::io;
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::fs::File`
[INFO] [stdout]   --> src/main.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 | use std::fs::File;
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Error` and `Write`
[INFO] [stdout]   --> src/main.rs:15:15
[INFO] [stdout]    |
[INFO] [stdout] 15 | use std::io::{Write, Error};
[INFO] [stdout]    |               ^^^^^  ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `idx`
[INFO] [stdout]  --> src/rust_book/ch3_common_concepts.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let idx = 123;
[INFO] [stdout]   |         ^^^ help: if this is intentional, prefix it with an underscore: `_idx`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a2`
[INFO] [stdout]   --> src/rust_book/ch3_common_concepts.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let a2 = [4; 6];
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_a2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `atuple`
[INFO] [stdout]   --> src/rust_book/ch3_common_concepts.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let atuple = ("123", 2, 3);
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_atuple`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `cnt`
[INFO] [stdout]   --> src/rust_book/ch3_common_concepts.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let cnt = loop {
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_cnt`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r3`
[INFO] [stdout]   --> src/rust_book/ch4_ownership.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let r3 = &mut s;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ss1`
[INFO] [stdout]   --> src/rust_book/ch4_ownership.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let ss1 = gives_ownership();
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_ss1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `localhost`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:14:13
[INFO] [stdout]    |
[INFO] [stdout] 14 |         let localhost = IpAddr{
[INFO] [stdout]    |             ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_localhost`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `loopback`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |         let loopback = IpAddr {
[INFO] [stdout]    |             ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_loopback`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `localhost`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:32:13
[INFO] [stdout]    |
[INFO] [stdout] 32 |         let localhost = IpAddr::V4(String::from("127.0.0.1"));
[INFO] [stdout]    |             ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_localhost`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `loopback`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:33:13
[INFO] [stdout]    |
[INFO] [stdout] 33 |         let loopback =  IpAddr::V6(String::from("::1"));
[INFO] [stdout]    |             ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_loopback`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:37:13
[INFO] [stdout]    |
[INFO] [stdout] 37 |         let x : i32 = 123;
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:38:13
[INFO] [stdout]    |
[INFO] [stdout] 38 |         let y : Option<i32> = Some(5);
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_struct.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let r1 = Rectangle { width : 12, height : 33};
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning[E0170]: pattern binding `A` is named the same as one of the variants of the type `rust_book::ch5_struct_enum_pattern_match::_pattern_match::test_match::XXD`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:37:14
[INFO] [stdout]    |
[INFO] [stdout] 37 |         Some(A) => println!("a"),
[INFO] [stdout]    |              ^ help: to match on the variant, qualify the path: `rust_book::ch5_struct_enum_pattern_match::_pattern_match::test_match::XXD::A`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bindings_with_variant_name)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]  --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let x : Option<UsState> = None;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let six = plus_one(five);
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_six`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i32`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:22:14
[INFO] [stdout]    |
[INFO] [stdout] 22 |         Some(i32) => println!("i32"),
[INFO] [stdout]    |              ^^^ help: if this is intentional, prefix it with an underscore: `_i32`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `A`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:37:14
[INFO] [stdout]    |
[INFO] [stdout] 37 |         Some(A) => println!("a"),
[INFO] [stdout]    |              ^ help: if this is intentional, prefix it with an underscore: `_A`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `does_not_exist`
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let does_not_exist = v.get(100);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_does_not_exist`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `row`
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:46:9
[INFO] [stdout]    |
[INFO] [stdout] 46 |     let row = vec![
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_row`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:61:9
[INFO] [stdout]    |
[INFO] [stdout] 61 |     let s = d1.to_string();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:62:9
[INFO] [stdout]    |
[INFO] [stdout] 62 |     let s = "Initial contents".to_string();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/rust_book/ch9_error_handling.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let f = match File::open("heex.txt") {
[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/rust_book/ch9_error_handling.rs:45:9
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let f = File::open("hello.txt").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: `i`
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime/lifetimes.rs:34:13
[INFO] [stdout]    |
[INFO] [stdout] 34 |         let i = ImportantExcerpt { part: first_sentence };
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime/lifetimes.rs:38:42
[INFO] [stdout]    |
[INFO] [stdout] 38 |         fn longest<'a, 'b>(s1 : &'a str, s2 : &'b str) -> &'a str {
[INFO] [stdout]    |                                          ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x1`
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let x1 = Point {x : 5, y : 10.3};
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_x1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x1`
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let x1 = Point {x : "5", y : 10.3};
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_x1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x1`
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |     let x1 = Point {x : 5.123, y : 10.3};
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_x1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `move_or_borrow` is never used
[INFO] [stdout]  --> src/rust_book/ch4_ownership.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn move_or_borrow() {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `owership` is never used
[INFO] [stdout]   --> src/rust_book/ch4_ownership.rs:22:4
[INFO] [stdout]    |
[INFO] [stdout] 22 | fn owership() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `borrow` is never used
[INFO] [stdout]   --> src/rust_book/ch4_ownership.rs:26:4
[INFO] [stdout]    |
[INFO] [stdout] 26 | fn borrow() {
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `move_sematics_for_user_defined_type` is never used
[INFO] [stdout]   --> src/rust_book/ch4_ownership.rs:41:4
[INFO] [stdout]    |
[INFO] [stdout] 41 | fn move_sematics_for_user_defined_type() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `show` is never used
[INFO] [stdout]    --> src/rust_book/ch4_ownership.rs:112:12
[INFO] [stdout]     |
[INFO] [stdout] 111 |     impl Point {
[INFO] [stdout]     |     ---------- method in this implementation
[INFO] [stdout] 112 |         fn show(&self) {
[INFO] [stdout]     |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `kind` and `address` are never read
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout]  9 |         struct IpAddr {
[INFO] [stdout]    |                ------ fields in this struct
[INFO] [stdout] 10 |             kind : IpAddrKind,
[INFO] [stdout]    |             ^^^^
[INFO] [stdout] 11 |             address : String,
[INFO] [stdout]    |             ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:28:16
[INFO] [stdout]    |
[INFO] [stdout] 28 |             V4(String),
[INFO] [stdout]    |             -- ^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             field in this variant
[INFO] [stdout]    |
[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] 28 -             V4(String),
[INFO] [stdout] 28 +             V4(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:29:16
[INFO] [stdout]    |
[INFO] [stdout] 29 |             V6(String),
[INFO] [stdout]    |             -- ^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             field in this variant
[INFO] [stdout]    |
[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] 29 -             V6(String),
[INFO] [stdout] 29 +             V6(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `width` and `height` are never read
[INFO] [stdout]  --> src/rust_book/ch5_struct_enum_pattern_match/_struct.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     struct Rectangle {
[INFO] [stdout]   |            --------- fields in this struct
[INFO] [stdout] 3 |         width : u32,
[INFO] [stdout]   |         ^^^^^
[INFO] [stdout] 4 |         height : u32,
[INFO] [stdout]   |         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `area` is never used
[INFO] [stdout]  --> src/rust_book/ch5_struct_enum_pattern_match/_struct.rs:8:12
[INFO] [stdout]   |
[INFO] [stdout] 7 |     impl Rectangle {
[INFO] [stdout]   |     -------------- method in this implementation
[INFO] [stdout] 8 |         fn area(&self) -> u32 {
[INFO] [stdout]   |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `can_hold` is never used
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_struct.rs:14:12
[INFO] [stdout]    |
[INFO] [stdout] 13 |     impl Rectangle {
[INFO] [stdout]    |     -------------- method in this implementation
[INFO] [stdout] 14 |         fn can_hold(&self, other: &Rectangle) -> bool {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Apple`, `Banane`, and `Watermelon` are never constructed
[INFO] [stdout]  --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     enum UsState {
[INFO] [stdout]   |          ------- variants in this enum
[INFO] [stdout] 4 |         Apple,
[INFO] [stdout]   |         ^^^^^
[INFO] [stdout] 5 |         Banane,
[INFO] [stdout]   |         ^^^^^^
[INFO] [stdout] 6 |         Watermelon,
[INFO] [stdout]   |         ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `A`, `B`, and `C` are never constructed
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     enum XXD {
[INFO] [stdout]    |          --- variants in this enum
[INFO] [stdout] 27 |         A,
[INFO] [stdout]    |         ^
[INFO] [stdout] 28 |         B,
[INFO] [stdout]    |         ^
[INFO] [stdout] 29 |         C,
[INFO] [stdout]    |         ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:37:13
[INFO] [stdout]    |
[INFO] [stdout] 37 |         Int(i32),
[INFO] [stdout]    |         --- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[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] 37 -         Int(i32),
[INFO] [stdout] 37 +         Int(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:38:15
[INFO] [stdout]    |
[INFO] [stdout] 38 |         Float(f64),
[INFO] [stdout]    |         ----- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[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] 38 -         Float(f64),
[INFO] [stdout] 38 +         Float(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:39:14
[INFO] [stdout]    |
[INFO] [stdout] 39 |         Text(String),
[INFO] [stdout]    |         ---- ^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[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] 39 -         Text(String),
[INFO] [stdout] 39 +         Text(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `read_username_from_file` is never used
[INFO] [stdout]   --> src/rust_book/ch9_error_handling.rs:16:4
[INFO] [stdout]    |
[INFO] [stdout] 16 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `x` and `y` are never read
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime.rs:46:9
[INFO] [stdout]    |
[INFO] [stdout] 45 |     struct Point<T, U> {
[INFO] [stdout]    |            ----- fields in this struct
[INFO] [stdout] 46 |         x : T,
[INFO] [stdout]    |         ^
[INFO] [stdout] 47 |         y : U,
[INFO] [stdout]    |         ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Summary` is never used
[INFO] [stdout]  --> src/rust_book/ch10_generic_traits_lefetime/traits.rs:1:7
[INFO] [stdout]   |
[INFO] [stdout] 1 | trait Summary {
[INFO] [stdout]   |       ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `NewsArticle` is never constructed
[INFO] [stdout]  --> src/rust_book/ch10_generic_traits_lefetime/traits.rs:9:8
[INFO] [stdout]   |
[INFO] [stdout] 9 | struct NewsArticle {
[INFO] [stdout]   |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Tweet` is never constructed
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime/traits.rs:16:8
[INFO] [stdout]    |
[INFO] [stdout] 16 | struct Tweet {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `part` is never read
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime/lifetimes.rs:27:13
[INFO] [stdout]    |
[INFO] [stdout] 26 |         struct ImportantExcerpt<'a> {
[INFO] [stdout]    |                ---------------- field in this struct
[INFO] [stdout] 27 |             part: &'a str,
[INFO] [stdout]    |             ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `longest` is never used
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime/lifetimes.rs:38:12
[INFO] [stdout]    |
[INFO] [stdout] 38 |         fn longest<'a, 'b>(s1 : &'a str, s2 : &'b str) -> &'a str {
[INFO] [stdout]    |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `A` should have a snake case name
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:37:14
[INFO] [stdout]    |
[INFO] [stdout] 37 |         Some(A) => println!("a"),
[INFO] [stdout]    |              ^ help: convert the identifier to snake case: `a`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: path statement with no effect
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:26:20
[INFO] [stdout]    |
[INFO] [stdout] 26 |     for i in &v1 { i; }
[INFO] [stdout]    |                    ^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(path_statements)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0170`.
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.43s
[INFO] running `Command { std: "docker" "inspect" "1ad8c37d0b4d1a52295cf0126eee0deb03e3135a4db24f27608d20226582e0a9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1ad8c37d0b4d1a52295cf0126eee0deb03e3135a4db24f27608d20226582e0a9", kill_on_drop: false }`
[INFO] [stdout] 1ad8c37d0b4d1a52295cf0126eee0deb03e3135a4db24f27608d20226582e0a9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 12153696e80c800117923b625118670a450eea2dd95492b9c240b56d7eeb376d
[INFO] running `Command { std: "docker" "start" "-a" "12153696e80c800117923b625118670a450eea2dd95492b9c240b56d7eeb376d", kill_on_drop: false }`
[INFO] [stderr]    Compiling learn_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> src/rust_book/ch4_ownership.rs:28:57
[INFO] [stdout]    |
[INFO] [stdout] 28 |     fn take_ownership(s : String) { println!("{}", s); };
[INFO] [stdout]    |                                                         ^ help: remove this semicolon
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(redundant_semicolons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> src/rust_book/ch4_ownership.rs:36:6
[INFO] [stdout]    |
[INFO] [stdout] 36 |     };
[INFO] [stdout]    |      ^ help: remove this semicolon
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `HashSet` and `VecDeque`
[INFO] [stdout]  --> src/rust_book/ch8_collections.rs:2:33
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::collections::{HashMap, HashSet, VecDeque};
[INFO] [stdout]   |                                 ^^^^^^^  ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::fs`
[INFO] [stdout]   --> src/rust_book/ch9_error_handling.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 | use std::fs;
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io`
[INFO] [stdout]   --> src/main.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | use std::io;
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::fs::File`
[INFO] [stdout]   --> src/main.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 | use std::fs::File;
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Error` and `Write`
[INFO] [stdout]   --> src/main.rs:15:15
[INFO] [stdout]    |
[INFO] [stdout] 15 | use std::io::{Write, Error};
[INFO] [stdout]    |               ^^^^^  ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `idx`
[INFO] [stdout]  --> src/rust_book/ch3_common_concepts.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let idx = 123;
[INFO] [stdout]   |         ^^^ help: if this is intentional, prefix it with an underscore: `_idx`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a2`
[INFO] [stdout]   --> src/rust_book/ch3_common_concepts.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let a2 = [4; 6];
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_a2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `atuple`
[INFO] [stdout]   --> src/rust_book/ch3_common_concepts.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let atuple = ("123", 2, 3);
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_atuple`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `cnt`
[INFO] [stdout]   --> src/rust_book/ch3_common_concepts.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let cnt = loop {
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_cnt`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r3`
[INFO] [stdout]   --> src/rust_book/ch4_ownership.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let r3 = &mut s;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ss1`
[INFO] [stdout]   --> src/rust_book/ch4_ownership.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let ss1 = gives_ownership();
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_ss1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `localhost`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:14:13
[INFO] [stdout]    |
[INFO] [stdout] 14 |         let localhost = IpAddr{
[INFO] [stdout]    |             ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_localhost`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `loopback`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |         let loopback = IpAddr {
[INFO] [stdout]    |             ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_loopback`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `localhost`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:32:13
[INFO] [stdout]    |
[INFO] [stdout] 32 |         let localhost = IpAddr::V4(String::from("127.0.0.1"));
[INFO] [stdout]    |             ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_localhost`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `loopback`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:33:13
[INFO] [stdout]    |
[INFO] [stdout] 33 |         let loopback =  IpAddr::V6(String::from("::1"));
[INFO] [stdout]    |             ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_loopback`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:37:13
[INFO] [stdout]    |
[INFO] [stdout] 37 |         let x : i32 = 123;
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:38:13
[INFO] [stdout]    |
[INFO] [stdout] 38 |         let y : Option<i32> = Some(5);
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_struct.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let r1 = Rectangle { width : 12, height : 33};
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning[E0170]: pattern binding `A` is named the same as one of the variants of the type `rust_book::ch5_struct_enum_pattern_match::_pattern_match::test_match::XXD`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:37:14
[INFO] [stdout]    |
[INFO] [stdout] 37 |         Some(A) => println!("a"),
[INFO] [stdout]    |              ^ help: to match on the variant, qualify the path: `rust_book::ch5_struct_enum_pattern_match::_pattern_match::test_match::XXD::A`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bindings_with_variant_name)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]  --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let x : Option<UsState> = None;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let six = plus_one(five);
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_six`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i32`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:22:14
[INFO] [stdout]    |
[INFO] [stdout] 22 |         Some(i32) => println!("i32"),
[INFO] [stdout]    |              ^^^ help: if this is intentional, prefix it with an underscore: `_i32`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `A`
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:37:14
[INFO] [stdout]    |
[INFO] [stdout] 37 |         Some(A) => println!("a"),
[INFO] [stdout]    |              ^ help: if this is intentional, prefix it with an underscore: `_A`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `does_not_exist`
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let does_not_exist = v.get(100);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_does_not_exist`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `row`
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:46:9
[INFO] [stdout]    |
[INFO] [stdout] 46 |     let row = vec![
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_row`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:61:9
[INFO] [stdout]    |
[INFO] [stdout] 61 |     let s = d1.to_string();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:62:9
[INFO] [stdout]    |
[INFO] [stdout] 62 |     let s = "Initial contents".to_string();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/rust_book/ch9_error_handling.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let f = match File::open("heex.txt") {
[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/rust_book/ch9_error_handling.rs:45:9
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let f = File::open("hello.txt").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: `i`
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime/lifetimes.rs:34:13
[INFO] [stdout]    |
[INFO] [stdout] 34 |         let i = ImportantExcerpt { part: first_sentence };
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime/lifetimes.rs:38:42
[INFO] [stdout]    |
[INFO] [stdout] 38 |         fn longest<'a, 'b>(s1 : &'a str, s2 : &'b str) -> &'a str {
[INFO] [stdout]    |                                          ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x1`
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let x1 = Point {x : 5, y : 10.3};
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_x1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x1`
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let x1 = Point {x : "5", y : 10.3};
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_x1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x1`
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |     let x1 = Point {x : 5.123, y : 10.3};
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_x1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `move_or_borrow` is never used
[INFO] [stdout]  --> src/rust_book/ch4_ownership.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn move_or_borrow() {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `owership` is never used
[INFO] [stdout]   --> src/rust_book/ch4_ownership.rs:22:4
[INFO] [stdout]    |
[INFO] [stdout] 22 | fn owership() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `borrow` is never used
[INFO] [stdout]   --> src/rust_book/ch4_ownership.rs:26:4
[INFO] [stdout]    |
[INFO] [stdout] 26 | fn borrow() {
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `move_sematics_for_user_defined_type` is never used
[INFO] [stdout]   --> src/rust_book/ch4_ownership.rs:41:4
[INFO] [stdout]    |
[INFO] [stdout] 41 | fn move_sematics_for_user_defined_type() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `show` is never used
[INFO] [stdout]    --> src/rust_book/ch4_ownership.rs:112:12
[INFO] [stdout]     |
[INFO] [stdout] 111 |     impl Point {
[INFO] [stdout]     |     ---------- method in this implementation
[INFO] [stdout] 112 |         fn show(&self) {
[INFO] [stdout]     |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `kind` and `address` are never read
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout]  9 |         struct IpAddr {
[INFO] [stdout]    |                ------ fields in this struct
[INFO] [stdout] 10 |             kind : IpAddrKind,
[INFO] [stdout]    |             ^^^^
[INFO] [stdout] 11 |             address : String,
[INFO] [stdout]    |             ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:28:16
[INFO] [stdout]    |
[INFO] [stdout] 28 |             V4(String),
[INFO] [stdout]    |             -- ^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             field in this variant
[INFO] [stdout]    |
[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] 28 -             V4(String),
[INFO] [stdout] 28 +             V4(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:29:16
[INFO] [stdout]    |
[INFO] [stdout] 29 |             V6(String),
[INFO] [stdout]    |             -- ^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             field in this variant
[INFO] [stdout]    |
[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] 29 -             V6(String),
[INFO] [stdout] 29 +             V6(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `width` and `height` are never read
[INFO] [stdout]  --> src/rust_book/ch5_struct_enum_pattern_match/_struct.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     struct Rectangle {
[INFO] [stdout]   |            --------- fields in this struct
[INFO] [stdout] 3 |         width : u32,
[INFO] [stdout]   |         ^^^^^
[INFO] [stdout] 4 |         height : u32,
[INFO] [stdout]   |         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `area` is never used
[INFO] [stdout]  --> src/rust_book/ch5_struct_enum_pattern_match/_struct.rs:8:12
[INFO] [stdout]   |
[INFO] [stdout] 7 |     impl Rectangle {
[INFO] [stdout]   |     -------------- method in this implementation
[INFO] [stdout] 8 |         fn area(&self) -> u32 {
[INFO] [stdout]   |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `can_hold` is never used
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_struct.rs:14:12
[INFO] [stdout]    |
[INFO] [stdout] 13 |     impl Rectangle {
[INFO] [stdout]    |     -------------- method in this implementation
[INFO] [stdout] 14 |         fn can_hold(&self, other: &Rectangle) -> bool {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Apple`, `Banane`, and `Watermelon` are never constructed
[INFO] [stdout]  --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     enum UsState {
[INFO] [stdout]   |          ------- variants in this enum
[INFO] [stdout] 4 |         Apple,
[INFO] [stdout]   |         ^^^^^
[INFO] [stdout] 5 |         Banane,
[INFO] [stdout]   |         ^^^^^^
[INFO] [stdout] 6 |         Watermelon,
[INFO] [stdout]   |         ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `A`, `B`, and `C` are never constructed
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     enum XXD {
[INFO] [stdout]    |          --- variants in this enum
[INFO] [stdout] 27 |         A,
[INFO] [stdout]    |         ^
[INFO] [stdout] 28 |         B,
[INFO] [stdout]    |         ^
[INFO] [stdout] 29 |         C,
[INFO] [stdout]    |         ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:37:13
[INFO] [stdout]    |
[INFO] [stdout] 37 |         Int(i32),
[INFO] [stdout]    |         --- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[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] 37 -         Int(i32),
[INFO] [stdout] 37 +         Int(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:38:15
[INFO] [stdout]    |
[INFO] [stdout] 38 |         Float(f64),
[INFO] [stdout]    |         ----- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[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] 38 -         Float(f64),
[INFO] [stdout] 38 +         Float(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:39:14
[INFO] [stdout]    |
[INFO] [stdout] 39 |         Text(String),
[INFO] [stdout]    |         ---- ^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[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] 39 -         Text(String),
[INFO] [stdout] 39 +         Text(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `read_username_from_file` is never used
[INFO] [stdout]   --> src/rust_book/ch9_error_handling.rs:16:4
[INFO] [stdout]    |
[INFO] [stdout] 16 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `x` and `y` are never read
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime.rs:46:9
[INFO] [stdout]    |
[INFO] [stdout] 45 |     struct Point<T, U> {
[INFO] [stdout]    |            ----- fields in this struct
[INFO] [stdout] 46 |         x : T,
[INFO] [stdout]    |         ^
[INFO] [stdout] 47 |         y : U,
[INFO] [stdout]    |         ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Summary` is never used
[INFO] [stdout]  --> src/rust_book/ch10_generic_traits_lefetime/traits.rs:1:7
[INFO] [stdout]   |
[INFO] [stdout] 1 | trait Summary {
[INFO] [stdout]   |       ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `NewsArticle` is never constructed
[INFO] [stdout]  --> src/rust_book/ch10_generic_traits_lefetime/traits.rs:9:8
[INFO] [stdout]   |
[INFO] [stdout] 9 | struct NewsArticle {
[INFO] [stdout]   |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Tweet` is never constructed
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime/traits.rs:16:8
[INFO] [stdout]    |
[INFO] [stdout] 16 | struct Tweet {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `part` is never read
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime/lifetimes.rs:27:13
[INFO] [stdout]    |
[INFO] [stdout] 26 |         struct ImportantExcerpt<'a> {
[INFO] [stdout]    |                ---------------- field in this struct
[INFO] [stdout] 27 |             part: &'a str,
[INFO] [stdout]    |             ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `longest` is never used
[INFO] [stdout]   --> src/rust_book/ch10_generic_traits_lefetime/lifetimes.rs:38:12
[INFO] [stdout]    |
[INFO] [stdout] 38 |         fn longest<'a, 'b>(s1 : &'a str, s2 : &'b str) -> &'a str {
[INFO] [stdout]    |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `A` should have a snake case name
[INFO] [stdout]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:37:14
[INFO] [stdout]    |
[INFO] [stdout] 37 |         Some(A) => println!("a"),
[INFO] [stdout]    |              ^ help: convert the identifier to snake case: `a`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: path statement with no effect
[INFO] [stdout]   --> src/rust_book/ch8_collections.rs:26:20
[INFO] [stdout]    |
[INFO] [stdout] 26 |     for i in &v1 { i; }
[INFO] [stdout]    |                    ^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(path_statements)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0170`.
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.38s
[INFO] running `Command { std: "docker" "inspect" "12153696e80c800117923b625118670a450eea2dd95492b9c240b56d7eeb376d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "12153696e80c800117923b625118670a450eea2dd95492b9c240b56d7eeb376d", kill_on_drop: false }`
[INFO] [stdout] 12153696e80c800117923b625118670a450eea2dd95492b9c240b56d7eeb376d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 370fef18591a12d4229a73be946034eb6075750bc8c39817014f3d5fbe881698
[INFO] running `Command { std: "docker" "start" "-a" "370fef18591a12d4229a73be946034eb6075750bc8c39817014f3d5fbe881698", kill_on_drop: false }`
[INFO] [stderr] warning: unnecessary trailing semicolon
[INFO] [stderr]   --> src/rust_book/ch4_ownership.rs:28:57
[INFO] [stderr]    |
[INFO] [stderr] 28 |     fn take_ownership(s : String) { println!("{}", s); };
[INFO] [stderr]    |                                                         ^ help: remove this semicolon
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(redundant_semicolons)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary trailing semicolon
[INFO] [stderr]   --> src/rust_book/ch4_ownership.rs:36:6
[INFO] [stderr]    |
[INFO] [stderr] 36 |     };
[INFO] [stderr]    |      ^ help: remove this semicolon
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `HashSet` and `VecDeque`
[INFO] [stderr]  --> src/rust_book/ch8_collections.rs:2:33
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::collections::{HashMap, HashSet, VecDeque};
[INFO] [stderr]   |                                 ^^^^^^^  ^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::fs`
[INFO] [stderr]   --> src/rust_book/ch9_error_handling.rs:12:5
[INFO] [stderr]    |
[INFO] [stderr] 12 | use std::fs;
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::io`
[INFO] [stderr]   --> src/main.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 | use std::io;
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::fs::File`
[INFO] [stderr]   --> src/main.rs:14:5
[INFO] [stderr]    |
[INFO] [stderr] 14 | use std::fs::File;
[INFO] [stderr]    |     ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `Error` and `Write`
[INFO] [stderr]   --> src/main.rs:15:15
[INFO] [stderr]    |
[INFO] [stderr] 15 | use std::io::{Write, Error};
[INFO] [stderr]    |               ^^^^^  ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `idx`
[INFO] [stderr]  --> src/rust_book/ch3_common_concepts.rs:7:9
[INFO] [stderr]   |
[INFO] [stderr] 7 |     let idx = 123;
[INFO] [stderr]   |         ^^^ help: if this is intentional, prefix it with an underscore: `_idx`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `a2`
[INFO] [stderr]   --> src/rust_book/ch3_common_concepts.rs:12:9
[INFO] [stderr]    |
[INFO] [stderr] 12 |     let a2 = [4; 6];
[INFO] [stderr]    |         ^^ help: if this is intentional, prefix it with an underscore: `_a2`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `atuple`
[INFO] [stderr]   --> src/rust_book/ch3_common_concepts.rs:13:9
[INFO] [stderr]    |
[INFO] [stderr] 13 |     let atuple = ("123", 2, 3);
[INFO] [stderr]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_atuple`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `cnt`
[INFO] [stderr]   --> src/rust_book/ch3_common_concepts.rs:51:9
[INFO] [stderr]    |
[INFO] [stderr] 51 |     let cnt = loop {
[INFO] [stderr]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_cnt`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `r3`
[INFO] [stderr]   --> src/rust_book/ch4_ownership.rs:16:9
[INFO] [stderr]    |
[INFO] [stderr] 16 |     let r3 = &mut s;
[INFO] [stderr]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r3`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `ss1`
[INFO] [stderr]   --> src/rust_book/ch4_ownership.rs:37:9
[INFO] [stderr]    |
[INFO] [stderr] 37 |     let ss1 = gives_ownership();
[INFO] [stderr]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_ss1`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `localhost`
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:14:13
[INFO] [stderr]    |
[INFO] [stderr] 14 |         let localhost = IpAddr{
[INFO] [stderr]    |             ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_localhost`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `loopback`
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:19:13
[INFO] [stderr]    |
[INFO] [stderr] 19 |         let loopback = IpAddr {
[INFO] [stderr]    |             ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_loopback`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `localhost`
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:32:13
[INFO] [stderr]    |
[INFO] [stderr] 32 |         let localhost = IpAddr::V4(String::from("127.0.0.1"));
[INFO] [stderr]    |             ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_localhost`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `loopback`
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:33:13
[INFO] [stderr]    |
[INFO] [stderr] 33 |         let loopback =  IpAddr::V6(String::from("::1"));
[INFO] [stderr]    |             ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_loopback`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:37:13
[INFO] [stderr]    |
[INFO] [stderr] 37 |         let x : i32 = 123;
[INFO] [stderr]    |             ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `y`
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:38:13
[INFO] [stderr]    |
[INFO] [stderr] 38 |         let y : Option<i32> = Some(5);
[INFO] [stderr]    |             ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `r1`
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_struct.rs:23:9
[INFO] [stderr]    |
[INFO] [stderr] 23 |     let r1 = Rectangle { width : 12, height : 33};
[INFO] [stderr]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stderr] 
[INFO] [stderr] warning[E0170]: pattern binding `A` is named the same as one of the variants of the type `rust_book::ch5_struct_enum_pattern_match::_pattern_match::test_match::XXD`
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:37:14
[INFO] [stderr]    |
[INFO] [stderr] 37 |         Some(A) => println!("a"),
[INFO] [stderr]    |              ^ help: to match on the variant, qualify the path: `rust_book::ch5_struct_enum_pattern_match::_pattern_match::test_match::XXD::A`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(bindings_with_variant_name)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]  --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:9:9
[INFO] [stderr]   |
[INFO] [stderr] 9 |     let x : Option<UsState> = None;
[INFO] [stderr]   |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `six`
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:19:9
[INFO] [stderr]    |
[INFO] [stderr] 19 |     let six = plus_one(five);
[INFO] [stderr]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_six`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `i32`
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:22:14
[INFO] [stderr]    |
[INFO] [stderr] 22 |         Some(i32) => println!("i32"),
[INFO] [stderr]    |              ^^^ help: if this is intentional, prefix it with an underscore: `_i32`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `A`
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:37:14
[INFO] [stderr]    |
[INFO] [stderr] 37 |         Some(A) => println!("a"),
[INFO] [stderr]    |              ^ help: if this is intentional, prefix it with an underscore: `_A`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `does_not_exist`
[INFO] [stderr]   --> src/rust_book/ch8_collections.rs:11:9
[INFO] [stderr]    |
[INFO] [stderr] 11 |     let does_not_exist = v.get(100);
[INFO] [stderr]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_does_not_exist`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `row`
[INFO] [stderr]   --> src/rust_book/ch8_collections.rs:46:9
[INFO] [stderr]    |
[INFO] [stderr] 46 |     let row = vec![
[INFO] [stderr]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_row`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s`
[INFO] [stderr]   --> src/rust_book/ch8_collections.rs:61:9
[INFO] [stderr]    |
[INFO] [stderr] 61 |     let s = d1.to_string();
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s`
[INFO] [stderr]   --> src/rust_book/ch8_collections.rs:62:9
[INFO] [stderr]    |
[INFO] [stderr] 62 |     let s = "Initial contents".to_string();
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `f`
[INFO] [stderr]   --> src/rust_book/ch9_error_handling.rs:33:9
[INFO] [stderr]    |
[INFO] [stderr] 33 |     let f = match File::open("heex.txt") {
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `f`
[INFO] [stderr]   --> src/rust_book/ch9_error_handling.rs:45:9
[INFO] [stderr]    |
[INFO] [stderr] 45 |     let f = File::open("hello.txt").unwrap_or_else(|error| {
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `i`
[INFO] [stderr]   --> src/rust_book/ch10_generic_traits_lefetime/lifetimes.rs:34:13
[INFO] [stderr]    |
[INFO] [stderr] 34 |         let i = ImportantExcerpt { part: first_sentence };
[INFO] [stderr]    |             ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s2`
[INFO] [stderr]   --> src/rust_book/ch10_generic_traits_lefetime/lifetimes.rs:38:42
[INFO] [stderr]    |
[INFO] [stderr] 38 |         fn longest<'a, 'b>(s1 : &'a str, s2 : &'b str) -> &'a str {
[INFO] [stderr]    |                                          ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x1`
[INFO] [stderr]   --> src/rust_book/ch10_generic_traits_lefetime.rs:50:9
[INFO] [stderr]    |
[INFO] [stderr] 50 |     let x1 = Point {x : 5, y : 10.3};
[INFO] [stderr]    |         ^^ help: if this is intentional, prefix it with an underscore: `_x1`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x1`
[INFO] [stderr]   --> src/rust_book/ch10_generic_traits_lefetime.rs:51:9
[INFO] [stderr]    |
[INFO] [stderr] 51 |     let x1 = Point {x : "5", y : 10.3};
[INFO] [stderr]    |         ^^ help: if this is intentional, prefix it with an underscore: `_x1`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x1`
[INFO] [stderr]   --> src/rust_book/ch10_generic_traits_lefetime.rs:52:9
[INFO] [stderr]    |
[INFO] [stderr] 52 |     let x1 = Point {x : 5.123, y : 10.3};
[INFO] [stderr]    |         ^^ help: if this is intentional, prefix it with an underscore: `_x1`
[INFO] [stderr] 
[INFO] [stderr] warning: function `move_or_borrow` is never used
[INFO] [stderr]  --> src/rust_book/ch4_ownership.rs:1:4
[INFO] [stderr]   |
[INFO] [stderr] 1 | fn move_or_borrow() {
[INFO] [stdout] 
[INFO] [stderr]   |    ^^^^^^^^^^^^^^
[INFO] [stdout] running 4 tests
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function `owership` is never used
[INFO] [stderr]   --> src/rust_book/ch4_ownership.rs:22:4
[INFO] [stderr]    |
[INFO] [stderr] 22 | fn owership() {
[INFO] [stderr]    |    ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `borrow` is never used
[INFO] [stderr]   --> src/rust_book/ch4_ownership.rs:26:4
[INFO] [stderr]    |
[INFO] [stderr] 26 | fn borrow() {
[INFO] [stderr]    |    ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `move_sematics_for_user_defined_type` is never used
[INFO] [stderr]   --> src/rust_book/ch4_ownership.rs:41:4
[INFO] [stderr]    |
[INFO] [stderr] 41 | fn move_sematics_for_user_defined_type() {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method `show` is never used
[INFO] [stderr]    --> src/rust_book/ch4_ownership.rs:112:12
[INFO] [stderr]     |
[INFO] [stderr] 111 |     impl Point {
[INFO] [stderr]     |     ---------- method in this implementation
[INFO] [stderr] 112 |         fn show(&self) {
[INFO] [stderr]     |            ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: fields `kind` and `address` are never read
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:10:13
[INFO] [stderr]    |
[INFO] [stderr]  9 |         struct IpAddr {
[INFO] [stderr]    |                ------ fields in this struct
[INFO] [stderr] 10 |             kind : IpAddrKind,
[INFO] [stderr]    |             ^^^^
[INFO] [stderr] 11 |             address : String,
[INFO] [stderr]    |             ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field `0` is never read
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:28:16
[INFO] [stderr]    |
[INFO] [stderr] 28 |             V4(String),
[INFO] [stderr]    |             -- ^^^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             field in this variant
[INFO] [stderr]    |
[INFO] [stderr] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stderr]    |
[INFO] [stderr] 28 -             V4(String),
[INFO] [stderr] 28 +             V4(()),
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: field `0` is never read
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_enum.rs:29:16
[INFO] [stderr]    |
[INFO] [stderr] 29 |             V6(String),
[INFO] [stderr]    |             -- ^^^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             field in this variant
[INFO] [stderr]    |
[INFO] [stderr] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stderr]    |
[INFO] [stderr] 29 -             V6(String),
[INFO] [stderr] 29 +             V6(()),
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: fields `width` and `height` are never read
[INFO] [stderr]  --> src/rust_book/ch5_struct_enum_pattern_match/_struct.rs:3:9
[INFO] [stderr]   |
[INFO] [stderr] 2 |     struct Rectangle {
[INFO] [stderr]   |            --------- fields in this struct
[INFO] [stderr] 3 |         width : u32,
[INFO] [stderr]   |         ^^^^^
[INFO] [stderr] 4 |         height : u32,
[INFO] [stderr]   |         ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method `area` is never used
[INFO] [stderr]  --> src/rust_book/ch5_struct_enum_pattern_match/_struct.rs:8:12
[INFO] [stderr]   |
[INFO] [stderr] 7 |     impl Rectangle {
[INFO] [stderr]   |     -------------- method in this implementation
[INFO] [stderr] 8 |         fn area(&self) -> u32 {
[INFO] [stderr]   |            ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method `can_hold` is never used
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_struct.rs:14:12
[INFO] [stderr]    |
[INFO] [stderr] 13 |     impl Rectangle {
[INFO] [stderr]    |     -------------- method in this implementation
[INFO] [stderr] 14 |         fn can_hold(&self, other: &Rectangle) -> bool {
[INFO] [stderr]    |            ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variants `Apple`, `Banane`, and `Watermelon` are never constructed
[INFO] [stderr]  --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:4:9
[INFO] [stderr]   |
[INFO] [stderr] 3 |     enum UsState {
[INFO] [stderr]   |          ------- variants in this enum
[INFO] [stderr] 4 |         Apple,
[INFO] [stderr]   |         ^^^^^
[INFO] [stderr] 5 |         Banane,
[INFO] [stderr]   |         ^^^^^^
[INFO] [stderr] 6 |         Watermelon,
[INFO] [stderr]   |         ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variants `A`, `B`, and `C` are never constructed
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:27:9
[INFO] [stderr]    |
[INFO] [stderr] 26 |     enum XXD {
[INFO] [stderr]    |          --- variants in this enum
[INFO] [stderr] 27 |         A,
[INFO] [stderr]    |         ^
[INFO] [stderr] 28 |         B,
[INFO] [stderr]    |         ^
[INFO] [stderr] 29 |         C,
[INFO] [stderr]    |         ^
[INFO] [stderr] 
[INFO] [stderr] warning: field `0` is never read
[INFO] [stderr]   --> src/rust_book/ch8_collections.rs:37:13
[INFO] [stderr]    |
[INFO] [stderr] 37 |         Int(i32),
[INFO] [stderr]    |         --- ^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         field in this variant
[INFO] [stderr]    |
[INFO] [stderr] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stderr]    |
[INFO] [stderr] 37 -         Int(i32),
[INFO] [stderr] 37 +         Int(()),
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: field `0` is never read
[INFO] [stderr]   --> src/rust_book/ch8_collections.rs:38:15
[INFO] [stderr]    |
[INFO] [stderr] 38 |         Float(f64),
[INFO] [stderr]    |         ----- ^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         field in this variant
[INFO] [stderr]    |
[INFO] [stderr] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stderr]    |
[INFO] [stderr] 38 -         Float(f64),
[INFO] [stderr] 38 +         Float(()),
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: field `0` is never read
[INFO] [stderr]   --> src/rust_book/ch8_collections.rs:39:14
[INFO] [stderr]    |
[INFO] [stderr] 39 |         Text(String),
[INFO] [stderr]    |         ---- ^^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         field in this variant
[INFO] [stderr]    |
[INFO] [stderr] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stderr]    |
[INFO] [stderr] 39 -         Text(String),
[INFO] [stderr] 39 +         Text(()),
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: function `read_username_from_file` is never used
[INFO] [stderr]   --> src/rust_book/ch9_error_handling.rs:16:4
[INFO] [stderr]    |
[INFO] [stderr] 16 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: fields `x` and `y` are never read
[INFO] [stderr]   --> src/rust_book/ch10_generic_traits_lefetime.rs:46:9
[INFO] [stderr]    |
[INFO] [stderr] 45 |     struct Point<T, U> {
[INFO] [stderr]    |            ----- fields in this struct
[INFO] [stderr] 46 |         x : T,
[INFO] [stderr]    |         ^
[INFO] [stderr] 47 |         y : U,
[INFO] [stderr]    |         ^
[INFO] [stderr] 
[INFO] [stderr] warning: trait `Summary` is never used
[INFO] [stderr]  --> src/rust_book/ch10_generic_traits_lefetime/traits.rs:1:7
[INFO] [stderr]   |
[INFO] [stderr] 1 | trait Summary {
[INFO] [stderr]   |       ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `NewsArticle` is never constructed
[INFO] [stderr]  --> src/rust_book/ch10_generic_traits_lefetime/traits.rs:9:8
[INFO] [stderr]   |
[INFO] [stderr] 9 | struct NewsArticle {
[INFO] [stderr]   |        ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `Tweet` is never constructed
[INFO] [stderr]   --> src/rust_book/ch10_generic_traits_lefetime/traits.rs:16:8
[INFO] [stderr]    |
[INFO] [stderr] 16 | struct Tweet {
[INFO] [stderr]    |        ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field `part` is never read
[INFO] [stderr]   --> src/rust_book/ch10_generic_traits_lefetime/lifetimes.rs:27:13
[INFO] [stderr]    |
[INFO] [stderr] 26 |         struct ImportantExcerpt<'a> {
[INFO] [stderr]    |                ---------------- field in this struct
[INFO] [stderr] 27 |             part: &'a str,
[INFO] [stderr]    |             ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `longest` is never used
[INFO] [stderr]   --> src/rust_book/ch10_generic_traits_lefetime/lifetimes.rs:38:12
[INFO] [stderr]    |
[INFO] [stderr] 38 |         fn longest<'a, 'b>(s1 : &'a str, s2 : &'b str) -> &'a str {
[INFO] [stderr]    |            ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable `A` should have a snake case name
[INFO] [stderr]   --> src/rust_book/ch5_struct_enum_pattern_match/_pattern_match.rs:37:14
[INFO] [stderr]    |
[INFO] [stderr] 37 |         Some(A) => println!("a"),
[INFO] [stderr]    |              ^ help: convert the identifier to snake case: `a`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: path statement with no effect
[INFO] [stderr]   --> src/rust_book/ch8_collections.rs:26:20
[INFO] [stderr]    |
[INFO] [stderr] 26 |     for i in &v1 { i; }
[INFO] [stderr]    |                    ^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(path_statements)]` on by default
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0170`.
[INFO] [stderr] warning: `learn_rust` (bin "learn_rust" test) generated 61 warnings (run `cargo fix --bin "learn_rust" --tests` to apply 6 suggestions)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.08s
[INFO] [stderr]      Running unittests src/main.rs (/opt/rustwide/target/debug/deps/learn_rust-1dfbfb392b10befe)
[INFO] [stdout] test rust_book::ch11_testing::tests::test ... ok
[INFO] [stdout] test rust_book::ch11_testing::tests::test3 ... ok
[INFO] [stdout] test rust_book::ch11_testing::tests::test2 ... ok
[INFO] [stdout] test rust_book::ch11_testing::tests::test4 - should panic ... FAILED
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout] 
[INFO] [stdout] ---- rust_book::ch11_testing::tests::test4 stdout ----
[INFO] [stdout] note: test did not panic as expected at src/rust_book/ch11_testing.rs:26:8
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout]     rust_book::ch11_testing::tests::test4
[INFO] [stdout] 
[INFO] [stdout] test result: FAILED. 3 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.01s
[INFO] [stdout] 
[INFO] [stderr] error: test failed, to rerun pass `--bin learn_rust`
[INFO] running `Command { std: "docker" "inspect" "370fef18591a12d4229a73be946034eb6075750bc8c39817014f3d5fbe881698", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "370fef18591a12d4229a73be946034eb6075750bc8c39817014f3d5fbe881698", kill_on_drop: false }`
[INFO] [stdout] 370fef18591a12d4229a73be946034eb6075750bc8c39817014f3d5fbe881698
