[INFO] cloning repository https://github.com/x931890193/hello_world
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/x931890193/hello_world" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fx931890193%2Fhello_world", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fx931890193%2Fhello_world'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 48c1c59ff7db089da742c6267117d181bcb89c9d
[INFO] testing x931890193/hello_world against master#1ddedbaa5919b7b3e70d984660e21e844c615c97 for pr-128400
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fx931890193%2Fhello_world" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/x931890193/hello_world on toolchain 1ddedbaa5919b7b3e70d984660e21e844c615c97
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1ddedbaa5919b7b3e70d984660e21e844c615c97" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/x931890193/hello_world
[INFO] finished tweaking git repo https://github.com/x931890193/hello_world
[INFO] tweaked toml for git repo https://github.com/x931890193/hello_world written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/x931890193/hello_world 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" "+1ddedbaa5919b7b3e70d984660e21e844c615c97" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+1ddedbaa5919b7b3e70d984660e21e844c615c97" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b33ca92c635deb8d6f9eedc822b9c13d2d58266f26e817a085b2df8a4e4eaf53
[INFO] running `Command { std: "docker" "start" "-a" "b33ca92c635deb8d6f9eedc822b9c13d2d58266f26e817a085b2df8a4e4eaf53", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b33ca92c635deb8d6f9eedc822b9c13d2d58266f26e817a085b2df8a4e4eaf53", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b33ca92c635deb8d6f9eedc822b9c13d2d58266f26e817a085b2df8a4e4eaf53", kill_on_drop: false }`
[INFO] [stdout] b33ca92c635deb8d6f9eedc822b9c13d2d58266f26e817a085b2df8a4e4eaf53
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+1ddedbaa5919b7b3e70d984660e21e844c615c97" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 45ee151de25acd0379cb2a014606ecd6321796762249b94fb7beff49db38b360
[INFO] running `Command { std: "docker" "start" "-a" "45ee151de25acd0379cb2a014606ecd6321796762249b94fb7beff49db38b360", kill_on_drop: false }`
[INFO] [stderr]    Compiling num-rational v0.4.0
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]    Compiling num-integer v0.1.45
[INFO] [stderr]    Compiling num-complex v0.4.1
[INFO] [stderr]    Compiling num-bigint v0.4.3
[INFO] [stderr]    Compiling num-iter v0.1.43
[INFO] [stderr]    Compiling num v0.4.0
[INFO] [stderr]    Compiling hello_world v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::cell::Ref`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::cell::Ref;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cmp::Ordering`
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cmp::Ordering;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/main.rs:27:10
[INFO] [stdout]    |
[INFO] [stdout] 27 |     for (i, &region) in regions.iter().enumerate() {
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `birds`
[INFO] [stdout]    --> src/main.rs:118:9
[INFO] [stdout]     |
[INFO] [stdout] 118 |     let birds: [Box<dyn Bird>; 2] = [Box::new(Swan{}), Box::new(Duck{})];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_birds`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let mut c = 30i32;
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/main.rs:22:8
[INFO] [stdout]    |
[INFO] [stdout] 22 | #[warn(unused_mut)]
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]    --> src/main.rs:185:9
[INFO] [stdout]     |
[INFO] [stdout] 185 |     let slice = &arr[1..]; //
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `black`
[INFO] [stdout]    --> src/main.rs:210:9
[INFO] [stdout]     |
[INFO] [stdout] 210 |     let black = Color(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: `t`
[INFO] [stdout]    --> src/main.rs:216:9
[INFO] [stdout]     |
[INFO] [stdout] 216 |     let t = Test;
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `first`
[INFO] [stdout]    --> src/main.rs:228:9
[INFO] [stdout]     |
[INFO] [stdout] 228 |     let first = &v3[0];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_first`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:268:9
[INFO] [stdout]     |
[INFO] [stdout] 268 |     let mut count = Counter::new();
[INFO] [stdout]     |         ----^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test` is never used
[INFO] [stdout]    --> src/main.rs:141:4
[INFO] [stdout]     |
[INFO] [stdout] 141 | fn test() {
[INFO] [stdout]     |    ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_word` is never used
[INFO] [stdout]    --> src/main.rs:151:4
[INFO] [stdout]     |
[INFO] [stdout] 151 | fn first_word(s: &String) -> usize {
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_word_v2` is never used
[INFO] [stdout]    --> src/main.rs:162:4
[INFO] [stdout]     |
[INFO] [stdout] 162 | fn first_word_v2(s: &String) -> &str {
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_word_v3` is never used
[INFO] [stdout]    --> src/main.rs:172:4
[INFO] [stdout]     |
[INFO] [stdout] 172 | fn first_word_v3(s: &str) -> &str {
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `arr_slice` is never used
[INFO] [stdout]    --> src/main.rs:183:4
[INFO] [stdout]     |
[INFO] [stdout] 183 | fn arr_slice() {
[INFO] [stdout]     |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_struct` is never used
[INFO] [stdout]    --> src/main.rs:189:4
[INFO] [stdout]     |
[INFO] [stdout] 189 | fn test_struct (){
[INFO] [stdout]     |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `tuple_struct` is never used
[INFO] [stdout]    --> src/main.rs:207:4
[INFO] [stdout]     |
[INFO] [stdout] 207 | fn tuple_struct(){
[INFO] [stdout]     |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `unit_like_struct` is never used
[INFO] [stdout]    --> src/main.rs:214:4
[INFO] [stdout]     |
[INFO] [stdout] 214 | fn unit_like_struct() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `MyOption` is never used
[INFO] [stdout]    --> src/main.rs:275:6
[INFO] [stdout]     |
[INFO] [stdout] 275 | enum MyOption<T> {
[INFO] [stdout]     |      ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Result` is never used
[INFO] [stdout]    --> src/main.rs:280:6
[INFO] [stdout]     |
[INFO] [stdout] 280 | enum Result<T, E> {
[INFO] [stdout]     |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test3` is never used
[INFO] [stdout]    --> src/main.rs:286:4
[INFO] [stdout]     |
[INFO] [stdout] 286 | fn test3() -> usize {
[INFO] [stdout]     |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Val` is never constructed
[INFO] [stdout]    --> src/main.rs:299:8
[INFO] [stdout]     |
[INFO] [stdout] 299 | struct Val<T> {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `value` is never used
[INFO] [stdout]    --> src/main.rs:304:8
[INFO] [stdout]     |
[INFO] [stdout] 303 | impl<T> Val<T> {
[INFO] [stdout]     | -------------- method in this implementation
[INFO] [stdout] 304 |     fn value(&self) -> &T {
[INFO] [stdout]     |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `sum2` is never used
[INFO] [stdout]    --> src/main.rs:342:4
[INFO] [stdout]     |
[INFO] [stdout] 342 | fn sum2<T: std::ops::Add<Output=T>>(x: T, y: T) -> T
[INFO] [stdout]     |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]    --> src/main.rs:355:8
[INFO] [stdout]     |
[INFO] [stdout] 354 | impl<T> Pair<T> {
[INFO] [stdout]     | --------------- associated function in this implementation
[INFO] [stdout] 355 |     fn new(x: T, y: T) -> Self {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `fly` is never used
[INFO] [stdout]    --> src/main.rs:465:8
[INFO] [stdout]     |
[INFO] [stdout] 464 | impl Swan {
[INFO] [stdout]     | --------- method in this implementation
[INFO] [stdout] 465 |     fn fly(&self) {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `static_dispatch_2` is never used
[INFO] [stdout]    --> src/main.rs:537:4
[INFO] [stdout]     |
[INFO] [stdout] 537 | fn static_dispatch_2<T: Foo>(x: T) {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `MyTrait` is never used
[INFO] [stdout]    --> src/main.rs:547:7
[INFO] [stdout]     |
[INFO] [stdout] 547 | trait MyTrait {
[INFO] [stdout]     |       ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `my_function` is never used
[INFO] [stdout]    --> src/main.rs:562:4
[INFO] [stdout]     |
[INFO] [stdout] 562 | fn my_function(x: impl MyTrait) -> impl MyTrait {
[INFO] [stdout]     |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 29 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.19s
[INFO] running `Command { std: "docker" "inspect" "45ee151de25acd0379cb2a014606ecd6321796762249b94fb7beff49db38b360", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "45ee151de25acd0379cb2a014606ecd6321796762249b94fb7beff49db38b360", kill_on_drop: false }`
[INFO] [stdout] 45ee151de25acd0379cb2a014606ecd6321796762249b94fb7beff49db38b360
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+1ddedbaa5919b7b3e70d984660e21e844c615c97" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d4fd3bccd02b52fbc859947536417b934530dc10c4d4921c289dd67af9778784
[INFO] running `Command { std: "docker" "start" "-a" "d4fd3bccd02b52fbc859947536417b934530dc10c4d4921c289dd67af9778784", kill_on_drop: false }`
[INFO] [stderr]    Compiling hello_world v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::cell::Ref`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::cell::Ref;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cmp::Ordering`
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cmp::Ordering;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/main.rs:27:10
[INFO] [stdout]    |
[INFO] [stdout] 27 |     for (i, &region) in regions.iter().enumerate() {
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `birds`
[INFO] [stdout]    --> src/main.rs:118:9
[INFO] [stdout]     |
[INFO] [stdout] 118 |     let birds: [Box<dyn Bird>; 2] = [Box::new(Swan{}), Box::new(Duck{})];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_birds`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let mut c = 30i32;
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/main.rs:22:8
[INFO] [stdout]    |
[INFO] [stdout] 22 | #[warn(unused_mut)]
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]    --> src/main.rs:185:9
[INFO] [stdout]     |
[INFO] [stdout] 185 |     let slice = &arr[1..]; //
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `black`
[INFO] [stdout]    --> src/main.rs:210:9
[INFO] [stdout]     |
[INFO] [stdout] 210 |     let black = Color(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: `t`
[INFO] [stdout]    --> src/main.rs:216:9
[INFO] [stdout]     |
[INFO] [stdout] 216 |     let t = Test;
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `first`
[INFO] [stdout]    --> src/main.rs:228:9
[INFO] [stdout]     |
[INFO] [stdout] 228 |     let first = &v3[0];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_first`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:268:9
[INFO] [stdout]     |
[INFO] [stdout] 268 |     let mut count = Counter::new();
[INFO] [stdout]     |         ----^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test` is never used
[INFO] [stdout]    --> src/main.rs:141:4
[INFO] [stdout]     |
[INFO] [stdout] 141 | fn test() {
[INFO] [stdout]     |    ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_word` is never used
[INFO] [stdout]    --> src/main.rs:151:4
[INFO] [stdout]     |
[INFO] [stdout] 151 | fn first_word(s: &String) -> usize {
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_word_v2` is never used
[INFO] [stdout]    --> src/main.rs:162:4
[INFO] [stdout]     |
[INFO] [stdout] 162 | fn first_word_v2(s: &String) -> &str {
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_word_v3` is never used
[INFO] [stdout]    --> src/main.rs:172:4
[INFO] [stdout]     |
[INFO] [stdout] 172 | fn first_word_v3(s: &str) -> &str {
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `arr_slice` is never used
[INFO] [stdout]    --> src/main.rs:183:4
[INFO] [stdout]     |
[INFO] [stdout] 183 | fn arr_slice() {
[INFO] [stdout]     |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_struct` is never used
[INFO] [stdout]    --> src/main.rs:189:4
[INFO] [stdout]     |
[INFO] [stdout] 189 | fn test_struct (){
[INFO] [stdout]     |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `tuple_struct` is never used
[INFO] [stdout]    --> src/main.rs:207:4
[INFO] [stdout]     |
[INFO] [stdout] 207 | fn tuple_struct(){
[INFO] [stdout]     |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `unit_like_struct` is never used
[INFO] [stdout]    --> src/main.rs:214:4
[INFO] [stdout]     |
[INFO] [stdout] 214 | fn unit_like_struct() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `MyOption` is never used
[INFO] [stdout]    --> src/main.rs:275:6
[INFO] [stdout]     |
[INFO] [stdout] 275 | enum MyOption<T> {
[INFO] [stdout]     |      ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Result` is never used
[INFO] [stdout]    --> src/main.rs:280:6
[INFO] [stdout]     |
[INFO] [stdout] 280 | enum Result<T, E> {
[INFO] [stdout]     |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test3` is never used
[INFO] [stdout]    --> src/main.rs:286:4
[INFO] [stdout]     |
[INFO] [stdout] 286 | fn test3() -> usize {
[INFO] [stdout]     |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Val` is never constructed
[INFO] [stdout]    --> src/main.rs:299:8
[INFO] [stdout]     |
[INFO] [stdout] 299 | struct Val<T> {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `value` is never used
[INFO] [stdout]    --> src/main.rs:304:8
[INFO] [stdout]     |
[INFO] [stdout] 303 | impl<T> Val<T> {
[INFO] [stdout]     | -------------- method in this implementation
[INFO] [stdout] 304 |     fn value(&self) -> &T {
[INFO] [stdout]     |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `sum2` is never used
[INFO] [stdout]    --> src/main.rs:342:4
[INFO] [stdout]     |
[INFO] [stdout] 342 | fn sum2<T: std::ops::Add<Output=T>>(x: T, y: T) -> T
[INFO] [stdout]     |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]    --> src/main.rs:355:8
[INFO] [stdout]     |
[INFO] [stdout] 354 | impl<T> Pair<T> {
[INFO] [stdout]     | --------------- associated function in this implementation
[INFO] [stdout] 355 |     fn new(x: T, y: T) -> Self {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `fly` is never used
[INFO] [stdout]    --> src/main.rs:465:8
[INFO] [stdout]     |
[INFO] [stdout] 464 | impl Swan {
[INFO] [stdout]     | --------- method in this implementation
[INFO] [stdout] 465 |     fn fly(&self) {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `static_dispatch_2` is never used
[INFO] [stdout]    --> src/main.rs:537:4
[INFO] [stdout]     |
[INFO] [stdout] 537 | fn static_dispatch_2<T: Foo>(x: T) {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `MyTrait` is never used
[INFO] [stdout]    --> src/main.rs:547:7
[INFO] [stdout]     |
[INFO] [stdout] 547 | trait MyTrait {
[INFO] [stdout]     |       ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `my_function` is never used
[INFO] [stdout]    --> src/main.rs:562:4
[INFO] [stdout]     |
[INFO] [stdout] 562 | fn my_function(x: impl MyTrait) -> impl MyTrait {
[INFO] [stdout]     |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 29 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.16s
[INFO] running `Command { std: "docker" "inspect" "d4fd3bccd02b52fbc859947536417b934530dc10c4d4921c289dd67af9778784", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d4fd3bccd02b52fbc859947536417b934530dc10c4d4921c289dd67af9778784", kill_on_drop: false }`
[INFO] [stdout] d4fd3bccd02b52fbc859947536417b934530dc10c4d4921c289dd67af9778784
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+1ddedbaa5919b7b3e70d984660e21e844c615c97" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] ba6406f4479f4fda4e4ff9bfd68d97d464fe207bb98e9c1635155cec63241789
[INFO] running `Command { std: "docker" "start" "-a" "ba6406f4479f4fda4e4ff9bfd68d97d464fe207bb98e9c1635155cec63241789", kill_on_drop: false }`
[INFO] [stderr] warning: unused import: `std::cell::Ref`
[INFO] [stderr]  --> src/main.rs:1:5
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::cell::Ref;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::cmp::Ordering`
[INFO] [stderr]  --> src/main.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::cmp::Ordering;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `i`
[INFO] [stderr]   --> src/main.rs:27:10
[INFO] [stderr]    |
[INFO] [stderr] 27 |     for (i, &region) in regions.iter().enumerate() {
[INFO] [stderr]    |          ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `birds`
[INFO] [stderr]    --> src/main.rs:118:9
[INFO] [stderr]     |
[INFO] [stderr] 118 |     let birds: [Box<dyn Bird>; 2] = [Box::new(Swan{}), Box::new(Duck{})];
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_birds`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:37:9
[INFO] [stderr]    |
[INFO] [stderr] 37 |     let mut c = 30i32;
[INFO] [stderr]    |         ----^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr] note: the lint level is defined here
[INFO] [stderr]   --> src/main.rs:22:8
[INFO] [stderr]    |
[INFO] [stderr] 22 | #[warn(unused_mut)]
[INFO] [stderr]    |        ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `slice`
[INFO] [stderr]    --> src/main.rs:185:9
[INFO] [stderr]     |
[INFO] [stderr] 185 |     let slice = &arr[1..]; //
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `black`
[INFO] [stderr]    --> src/main.rs:210:9
[INFO] [stderr]     |
[INFO] [stderr] 210 |     let black = Color(0, 0,0);
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_black`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `t`
[INFO] [stderr]    --> src/main.rs:216:9
[INFO] [stderr]     |
[INFO] [stderr] 216 |     let t = Test;
[INFO] [stderr]     |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `first`
[INFO] [stderr]    --> src/main.rs:228:9
[INFO] [stderr]     |
[INFO] [stderr] 228 |     let first = &v3[0];
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_first`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:268:9
[INFO] [stderr]     |
[INFO] [stderr] 268 |     let mut count = Counter::new();
[INFO] [stderr]     |         ----^^^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function `test` is never used
[INFO] [stderr]    --> src/main.rs:141:4
[INFO] [stderr]     |
[INFO] [stderr] 141 | fn test() {
[INFO] [stderr]     |    ^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function `first_word` is never used
[INFO] [stderr]    --> src/main.rs:151:4
[INFO] [stderr]     |
[INFO] [stderr] 151 | fn first_word(s: &String) -> usize {
[INFO] [stderr]     |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `first_word_v2` is never used
[INFO] [stderr]    --> src/main.rs:162:4
[INFO] [stderr]     |
[INFO] [stderr] 162 | fn first_word_v2(s: &String) -> &str {
[INFO] [stderr]     |    ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `first_word_v3` is never used
[INFO] [stderr]    --> src/main.rs:172:4
[INFO] [stderr]     |
[INFO] [stderr] 172 | fn first_word_v3(s: &str) -> &str {
[INFO] [stderr]     |    ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `arr_slice` is never used
[INFO] [stderr]    --> src/main.rs:183:4
[INFO] [stderr]     |
[INFO] [stderr] 183 | fn arr_slice() {
[INFO] [stderr]     |    ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `test_struct` is never used
[INFO] [stderr]    --> src/main.rs:189:4
[INFO] [stderr]     |
[INFO] [stderr] 189 | fn test_struct (){
[INFO] [stderr]     |    ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `tuple_struct` is never used
[INFO] [stderr]    --> src/main.rs:207:4
[INFO] [stderr]     |
[INFO] [stderr] 207 | fn tuple_struct(){
[INFO] [stderr]     |    ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `unit_like_struct` is never used
[INFO] [stderr]    --> src/main.rs:214:4
[INFO] [stderr]     |
[INFO] [stderr] 214 | fn unit_like_struct() {
[INFO] [stderr]     |    ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: enum `MyOption` is never used
[INFO] [stderr]    --> src/main.rs:275:6
[INFO] [stderr]     |
[INFO] [stderr] 275 | enum MyOption<T> {
[INFO] [stderr]     |      ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: enum `Result` is never used
[INFO] [stderr]    --> src/main.rs:280:6
[INFO] [stderr]     |
[INFO] [stderr] 280 | enum Result<T, E> {
[INFO] [stderr]     |      ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `test3` is never used
[INFO] [stderr]    --> src/main.rs:286:4
[INFO] [stderr]     |
[INFO] [stderr] 286 | fn test3() -> usize {
[INFO] [stderr]     |    ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `Val` is never constructed
[INFO] [stderr]    --> src/main.rs:299:8
[INFO] [stderr]     |
[INFO] [stderr] 299 | struct Val<T> {
[INFO] [stderr]     |        ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method `value` is never used
[INFO] [stderr]    --> src/main.rs:304:8
[INFO] [stderr]     |
[INFO] [stderr] 303 | impl<T> Val<T> {
[INFO] [stderr]     | -------------- method in this implementation
[INFO] [stderr] 304 |     fn value(&self) -> &T {
[INFO] [stderr]     |        ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `sum2` is never used
[INFO] [stderr]    --> src/main.rs:342:4
[INFO] [stderr]     |
[INFO] [stderr] 342 | fn sum2<T: std::ops::Add<Output=T>>(x: T, y: T) -> T
[INFO] [stderr]     |    ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function `new` is never used
[INFO] [stderr]    --> src/main.rs:355:8
[INFO] [stderr]     |
[INFO] [stderr] 354 | impl<T> Pair<T> {
[INFO] [stderr]     | --------------- associated function in this implementation
[INFO] [stderr] 355 |     fn new(x: T, y: T) -> Self {
[INFO] [stderr]     |        ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method `fly` is never used
[INFO] [stderr]    --> src/main.rs:465:8
[INFO] [stderr]     |
[INFO] [stderr] 464 | impl Swan {
[INFO] [stderr]     | --------- method in this implementation
[INFO] [stderr] 465 |     fn fly(&self) {
[INFO] [stderr]     |        ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `static_dispatch_2` is never used
[INFO] [stderr]    --> src/main.rs:537:4
[INFO] [stderr]     |
[INFO] [stderr] 537 | fn static_dispatch_2<T: Foo>(x: T) {
[INFO] [stderr]     |    ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: trait `MyTrait` is never used
[INFO] [stderr]    --> src/main.rs:547:7
[INFO] [stderr]     |
[INFO] [stderr] 547 | trait MyTrait {
[INFO] [stderr]     |       ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `my_function` is never used
[INFO] [stderr]    --> src/main.rs:562:4
[INFO] [stderr]     |
[INFO] [stderr] 562 | fn my_function(x: impl MyTrait) -> impl MyTrait {
[INFO] [stderr]     |    ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: `hello_world` (bin "hello_world" test) generated 29 warnings (run `cargo fix --bin "hello_world" --tests` to apply 4 suggestions)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running unittests src/main.rs (/opt/rustwide/target/debug/deps/hello_world-56d7540ae9be07ca)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "ba6406f4479f4fda4e4ff9bfd68d97d464fe207bb98e9c1635155cec63241789", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ba6406f4479f4fda4e4ff9bfd68d97d464fe207bb98e9c1635155cec63241789", kill_on_drop: false }`
[INFO] [stdout] ba6406f4479f4fda4e4ff9bfd68d97d464fe207bb98e9c1635155cec63241789
[INFO] testing x931890193/hello_world against try#33f1d8bb92813a1bfc23c093c9f443ab09290307 for pr-128400
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fx931890193%2Fhello_world" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/x931890193/hello_world on toolchain 33f1d8bb92813a1bfc23c093c9f443ab09290307
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/x931890193/hello_world
[INFO] finished tweaking git repo https://github.com/x931890193/hello_world
[INFO] tweaked toml for git repo https://github.com/x931890193/hello_world written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/x931890193/hello_world 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" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[INFO] testing x931890193/hello_world against try#33f1d8bb92813a1bfc23c093c9f443ab09290307 for pr-128400
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fx931890193%2Fhello_world" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/x931890193/hello_world on toolchain 33f1d8bb92813a1bfc23c093c9f443ab09290307
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/x931890193/hello_world
[INFO] finished tweaking git repo https://github.com/x931890193/hello_world
[INFO] tweaked toml for git repo https://github.com/x931890193/hello_world written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/x931890193/hello_world 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" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[INFO] testing x931890193/hello_world against try#33f1d8bb92813a1bfc23c093c9f443ab09290307 for pr-128400
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fx931890193%2Fhello_world" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/x931890193/hello_world on toolchain 33f1d8bb92813a1bfc23c093c9f443ab09290307
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/x931890193/hello_world
[INFO] finished tweaking git repo https://github.com/x931890193/hello_world
[INFO] tweaked toml for git repo https://github.com/x931890193/hello_world written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/x931890193/hello_world 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" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[INFO] testing x931890193/hello_world against try#33f1d8bb92813a1bfc23c093c9f443ab09290307 for pr-128400
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fx931890193%2Fhello_world" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/x931890193/hello_world on toolchain 33f1d8bb92813a1bfc23c093c9f443ab09290307
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/x931890193/hello_world
[INFO] finished tweaking git repo https://github.com/x931890193/hello_world
[INFO] tweaked toml for git repo https://github.com/x931890193/hello_world written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/x931890193/hello_world 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" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1c3b467dba09f1437e6784d5f65f0a2f300a9c6872568ff4c7e181fc8b7f26e2
[INFO] running `Command { std: "docker" "start" "-a" "1c3b467dba09f1437e6784d5f65f0a2f300a9c6872568ff4c7e181fc8b7f26e2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1c3b467dba09f1437e6784d5f65f0a2f300a9c6872568ff4c7e181fc8b7f26e2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1c3b467dba09f1437e6784d5f65f0a2f300a9c6872568ff4c7e181fc8b7f26e2", kill_on_drop: false }`
[INFO] [stdout] 1c3b467dba09f1437e6784d5f65f0a2f300a9c6872568ff4c7e181fc8b7f26e2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e0ff7ed9ff473aebf178d30928de1cc7ec57f14a39fa6b535a39007ed46c816a
[INFO] running `Command { std: "docker" "start" "-a" "e0ff7ed9ff473aebf178d30928de1cc7ec57f14a39fa6b535a39007ed46c816a", kill_on_drop: false }`
[INFO] [stderr]    Compiling num-rational v0.4.0
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]    Compiling num-iter v0.1.43
[INFO] [stderr]    Compiling num-integer v0.1.45
[INFO] [stderr]    Compiling num-complex v0.4.1
[INFO] [stderr]    Compiling num-bigint v0.4.3
[INFO] [stderr]    Compiling num v0.4.0
[INFO] [stderr]    Compiling hello_world v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::cell::Ref`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::cell::Ref;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cmp::Ordering`
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cmp::Ordering;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/main.rs:27:10
[INFO] [stdout]    |
[INFO] [stdout] 27 |     for (i, &region) in regions.iter().enumerate() {
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `birds`
[INFO] [stdout]    --> src/main.rs:118:9
[INFO] [stdout]     |
[INFO] [stdout] 118 |     let birds: [Box<dyn Bird>; 2] = [Box::new(Swan{}), Box::new(Duck{})];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_birds`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let mut c = 30i32;
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/main.rs:22:8
[INFO] [stdout]    |
[INFO] [stdout] 22 | #[warn(unused_mut)]
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]    --> src/main.rs:185:9
[INFO] [stdout]     |
[INFO] [stdout] 185 |     let slice = &arr[1..]; //
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `black`
[INFO] [stdout]    --> src/main.rs:210:9
[INFO] [stdout]     |
[INFO] [stdout] 210 |     let black = Color(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: `t`
[INFO] [stdout]    --> src/main.rs:216:9
[INFO] [stdout]     |
[INFO] [stdout] 216 |     let t = Test;
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `first`
[INFO] [stdout]    --> src/main.rs:228:9
[INFO] [stdout]     |
[INFO] [stdout] 228 |     let first = &v3[0];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_first`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:268:9
[INFO] [stdout]     |
[INFO] [stdout] 268 |     let mut count = Counter::new();
[INFO] [stdout]     |         ----^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test` is never used
[INFO] [stdout]    --> src/main.rs:141:4
[INFO] [stdout]     |
[INFO] [stdout] 141 | fn test() {
[INFO] [stdout]     |    ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_word` is never used
[INFO] [stdout]    --> src/main.rs:151:4
[INFO] [stdout]     |
[INFO] [stdout] 151 | fn first_word(s: &String) -> usize {
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_word_v2` is never used
[INFO] [stdout]    --> src/main.rs:162:4
[INFO] [stdout]     |
[INFO] [stdout] 162 | fn first_word_v2(s: &String) -> &str {
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_word_v3` is never used
[INFO] [stdout]    --> src/main.rs:172:4
[INFO] [stdout]     |
[INFO] [stdout] 172 | fn first_word_v3(s: &str) -> &str {
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `arr_slice` is never used
[INFO] [stdout]    --> src/main.rs:183:4
[INFO] [stdout]     |
[INFO] [stdout] 183 | fn arr_slice() {
[INFO] [stdout]     |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_struct` is never used
[INFO] [stdout]    --> src/main.rs:189:4
[INFO] [stdout]     |
[INFO] [stdout] 189 | fn test_struct (){
[INFO] [stdout]     |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `tuple_struct` is never used
[INFO] [stdout]    --> src/main.rs:207:4
[INFO] [stdout]     |
[INFO] [stdout] 207 | fn tuple_struct(){
[INFO] [stdout]     |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `unit_like_struct` is never used
[INFO] [stdout]    --> src/main.rs:214:4
[INFO] [stdout]     |
[INFO] [stdout] 214 | fn unit_like_struct() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `MyOption` is never used
[INFO] [stdout]    --> src/main.rs:275:6
[INFO] [stdout]     |
[INFO] [stdout] 275 | enum MyOption<T> {
[INFO] [stdout]     |      ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Result` is never used
[INFO] [stdout]    --> src/main.rs:280:6
[INFO] [stdout]     |
[INFO] [stdout] 280 | enum Result<T, E> {
[INFO] [stdout]     |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test3` is never used
[INFO] [stdout]    --> src/main.rs:286:4
[INFO] [stdout]     |
[INFO] [stdout] 286 | fn test3() -> usize {
[INFO] [stdout]     |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Val` is never constructed
[INFO] [stdout]    --> src/main.rs:299:8
[INFO] [stdout]     |
[INFO] [stdout] 299 | struct Val<T> {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `value` is never used
[INFO] [stdout]    --> src/main.rs:304:8
[INFO] [stdout]     |
[INFO] [stdout] 303 | impl<T> Val<T> {
[INFO] [stdout]     | -------------- method in this implementation
[INFO] [stdout] 304 |     fn value(&self) -> &T {
[INFO] [stdout]     |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `sum2` is never used
[INFO] [stdout]    --> src/main.rs:342:4
[INFO] [stdout]     |
[INFO] [stdout] 342 | fn sum2<T: std::ops::Add<Output=T>>(x: T, y: T) -> T
[INFO] [stdout]     |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]    --> src/main.rs:355:8
[INFO] [stdout]     |
[INFO] [stdout] 354 | impl<T> Pair<T> {
[INFO] [stdout]     | --------------- associated function in this implementation
[INFO] [stdout] 355 |     fn new(x: T, y: T) -> Self {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `fly` is never used
[INFO] [stdout]    --> src/main.rs:465:8
[INFO] [stdout]     |
[INFO] [stdout] 464 | impl Swan {
[INFO] [stdout]     | --------- method in this implementation
[INFO] [stdout] 465 |     fn fly(&self) {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `static_dispatch_2` is never used
[INFO] [stdout]    --> src/main.rs:537:4
[INFO] [stdout]     |
[INFO] [stdout] 537 | fn static_dispatch_2<T: Foo>(x: T) {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `MyTrait` is never used
[INFO] [stdout]    --> src/main.rs:547:7
[INFO] [stdout]     |
[INFO] [stdout] 547 | trait MyTrait {
[INFO] [stdout]     |       ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `my_function` is never used
[INFO] [stdout]    --> src/main.rs:562:4
[INFO] [stdout]     |
[INFO] [stdout] 562 | fn my_function(x: impl MyTrait) -> impl MyTrait {
[INFO] [stdout]     |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 29 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 4.02s
[INFO] running `Command { std: "docker" "inspect" "e0ff7ed9ff473aebf178d30928de1cc7ec57f14a39fa6b535a39007ed46c816a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e0ff7ed9ff473aebf178d30928de1cc7ec57f14a39fa6b535a39007ed46c816a", kill_on_drop: false }`
[INFO] [stdout] e0ff7ed9ff473aebf178d30928de1cc7ec57f14a39fa6b535a39007ed46c816a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5da014b362f12c7efe8fd7401baf49a4e9f696c27ebfa8d9ddad951efd334954
[INFO] running `Command { std: "docker" "start" "-a" "5da014b362f12c7efe8fd7401baf49a4e9f696c27ebfa8d9ddad951efd334954", kill_on_drop: false }`
[INFO] [stderr]    Compiling hello_world v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::cell::Ref`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::cell::Ref;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cmp::Ordering`
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cmp::Ordering;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/main.rs:27:10
[INFO] [stdout]    |
[INFO] [stdout] 27 |     for (i, &region) in regions.iter().enumerate() {
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `birds`
[INFO] [stdout]    --> src/main.rs:118:9
[INFO] [stdout]     |
[INFO] [stdout] 118 |     let birds: [Box<dyn Bird>; 2] = [Box::new(Swan{}), Box::new(Duck{})];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_birds`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let mut c = 30i32;
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/main.rs:22:8
[INFO] [stdout]    |
[INFO] [stdout] 22 | #[warn(unused_mut)]
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]    --> src/main.rs:185:9
[INFO] [stdout]     |
[INFO] [stdout] 185 |     let slice = &arr[1..]; //
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `black`
[INFO] [stdout]    --> src/main.rs:210:9
[INFO] [stdout]     |
[INFO] [stdout] 210 |     let black = Color(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: `t`
[INFO] [stdout]    --> src/main.rs:216:9
[INFO] [stdout]     |
[INFO] [stdout] 216 |     let t = Test;
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `first`
[INFO] [stdout]    --> src/main.rs:228:9
[INFO] [stdout]     |
[INFO] [stdout] 228 |     let first = &v3[0];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_first`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:268:9
[INFO] [stdout]     |
[INFO] [stdout] 268 |     let mut count = Counter::new();
[INFO] [stdout]     |         ----^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test` is never used
[INFO] [stdout]    --> src/main.rs:141:4
[INFO] [stdout]     |
[INFO] [stdout] 141 | fn test() {
[INFO] [stdout]     |    ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_word` is never used
[INFO] [stdout]    --> src/main.rs:151:4
[INFO] [stdout]     |
[INFO] [stdout] 151 | fn first_word(s: &String) -> usize {
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_word_v2` is never used
[INFO] [stdout]    --> src/main.rs:162:4
[INFO] [stdout]     |
[INFO] [stdout] 162 | fn first_word_v2(s: &String) -> &str {
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_word_v3` is never used
[INFO] [stdout]    --> src/main.rs:172:4
[INFO] [stdout]     |
[INFO] [stdout] 172 | fn first_word_v3(s: &str) -> &str {
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `arr_slice` is never used
[INFO] [stdout]    --> src/main.rs:183:4
[INFO] [stdout]     |
[INFO] [stdout] 183 | fn arr_slice() {
[INFO] [stdout]     |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test_struct` is never used
[INFO] [stdout]    --> src/main.rs:189:4
[INFO] [stdout]     |
[INFO] [stdout] 189 | fn test_struct (){
[INFO] [stdout]     |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `tuple_struct` is never used
[INFO] [stdout]    --> src/main.rs:207:4
[INFO] [stdout]     |
[INFO] [stdout] 207 | fn tuple_struct(){
[INFO] [stdout]     |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `unit_like_struct` is never used
[INFO] [stdout]    --> src/main.rs:214:4
[INFO] [stdout]     |
[INFO] [stdout] 214 | fn unit_like_struct() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `MyOption` is never used
[INFO] [stdout]    --> src/main.rs:275:6
[INFO] [stdout]     |
[INFO] [stdout] 275 | enum MyOption<T> {
[INFO] [stdout]     |      ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Result` is never used
[INFO] [stdout]    --> src/main.rs:280:6
[INFO] [stdout]     |
[INFO] [stdout] 280 | enum Result<T, E> {
[INFO] [stdout]     |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `test3` is never used
[INFO] [stdout]    --> src/main.rs:286:4
[INFO] [stdout]     |
[INFO] [stdout] 286 | fn test3() -> usize {
[INFO] [stdout]     |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Val` is never constructed
[INFO] [stdout]    --> src/main.rs:299:8
[INFO] [stdout]     |
[INFO] [stdout] 299 | struct Val<T> {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `value` is never used
[INFO] [stdout]    --> src/main.rs:304:8
[INFO] [stdout]     |
[INFO] [stdout] 303 | impl<T> Val<T> {
[INFO] [stdout]     | -------------- method in this implementation
[INFO] [stdout] 304 |     fn value(&self) -> &T {
[INFO] [stdout]     |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `sum2` is never used
[INFO] [stdout]    --> src/main.rs:342:4
[INFO] [stdout]     |
[INFO] [stdout] 342 | fn sum2<T: std::ops::Add<Output=T>>(x: T, y: T) -> T
[INFO] [stdout]     |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]    --> src/main.rs:355:8
[INFO] [stdout]     |
[INFO] [stdout] 354 | impl<T> Pair<T> {
[INFO] [stdout]     | --------------- associated function in this implementation
[INFO] [stdout] 355 |     fn new(x: T, y: T) -> Self {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `fly` is never used
[INFO] [stdout]    --> src/main.rs:465:8
[INFO] [stdout]     |
[INFO] [stdout] 464 | impl Swan {
[INFO] [stdout]     | --------- method in this implementation
[INFO] [stdout] 465 |     fn fly(&self) {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `static_dispatch_2` is never used
[INFO] [stdout]    --> src/main.rs:537:4
[INFO] [stdout]     |
[INFO] [stdout] 537 | fn static_dispatch_2<T: Foo>(x: T) {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `MyTrait` is never used
[INFO] [stdout]    --> src/main.rs:547:7
[INFO] [stdout]     |
[INFO] [stdout] 547 | trait MyTrait {
[INFO] [stdout]     |       ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `my_function` is never used
[INFO] [stdout]    --> src/main.rs:562:4
[INFO] [stdout]     |
[INFO] [stdout] 562 | fn my_function(x: impl MyTrait) -> impl MyTrait {
[INFO] [stdout]     |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 29 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.61s
[INFO] running `Command { std: "docker" "inspect" "5da014b362f12c7efe8fd7401baf49a4e9f696c27ebfa8d9ddad951efd334954", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5da014b362f12c7efe8fd7401baf49a4e9f696c27ebfa8d9ddad951efd334954", kill_on_drop: false }`
[INFO] [stdout] 5da014b362f12c7efe8fd7401baf49a4e9f696c27ebfa8d9ddad951efd334954
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 0707636d261811d3ff2c0286698e0c495e1b6a5d45ea8a3d4b1c606c032d4712
[INFO] running `Command { std: "docker" "start" "-a" "0707636d261811d3ff2c0286698e0c495e1b6a5d45ea8a3d4b1c606c032d4712", kill_on_drop: false }`
[INFO] [stderr] warning: unused import: `std::cell::Ref`
[INFO] [stderr]  --> src/main.rs:1:5
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::cell::Ref;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::cmp::Ordering`
[INFO] [stderr]  --> src/main.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::cmp::Ordering;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `i`
[INFO] [stderr]   --> src/main.rs:27:10
[INFO] [stderr]    |
[INFO] [stderr] 27 |     for (i, &region) in regions.iter().enumerate() {
[INFO] [stderr]    |          ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `birds`
[INFO] [stderr]    --> src/main.rs:118:9
[INFO] [stderr]     |
[INFO] [stderr] 118 |     let birds: [Box<dyn Bird>; 2] = [Box::new(Swan{}), Box::new(Duck{})];
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_birds`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:37:9
[INFO] [stderr]    |
[INFO] [stderr] 37 |     let mut c = 30i32;
[INFO] [stderr]    |         ----^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr] note: the lint level is defined here
[INFO] [stderr]   --> src/main.rs:22:8
[INFO] [stderr]    |
[INFO] [stderr] 22 | #[warn(unused_mut)]
[INFO] [stderr]    |        ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `slice`
[INFO] [stderr]    --> src/main.rs:185:9
[INFO] [stderr]     |
[INFO] [stderr] 185 |     let slice = &arr[1..]; //
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `black`
[INFO] [stderr]    --> src/main.rs:210:9
[INFO] [stderr]     |
[INFO] [stderr] 210 |     let black = Color(0, 0,0);
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_black`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `t`
[INFO] [stderr]    --> src/main.rs:216:9
[INFO] [stderr]     |
[INFO] [stderr] 216 |     let t = Test;
[INFO] [stderr]     |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `first`
[INFO] [stderr]    --> src/main.rs:228:9
[INFO] [stderr]     |
[INFO] [stderr] 228 |     let first = &v3[0];
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_first`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:268:9
[INFO] [stderr]     |
[INFO] [stderr] 268 |     let mut count = Counter::new();
[INFO] [stderr]     |         ----^^^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function `test` is never used
[INFO] [stderr]    --> src/main.rs:141:4
[INFO] [stderr]     |
[INFO] [stderr] 141 | fn test() {
[INFO] [stderr]     |    ^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function `first_word` is never used
[INFO] [stderr]    --> src/main.rs:151:4
[INFO] [stderr]     |
[INFO] [stderr] 151 | fn first_word(s: &String) -> usize {
[INFO] [stderr]     |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `first_word_v2` is never used
[INFO] [stderr]    --> src/main.rs:162:4
[INFO] [stderr]     |
[INFO] [stderr] 162 | fn first_word_v2(s: &String) -> &str {
[INFO] [stderr]     |    ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr] warning: function `first_word_v3` is never used
[INFO] [stderr]    --> src/main.rs:172:4
[INFO] [stderr]     |
[INFO] [stderr] 172 | fn first_word_v3(s: &str) -> &str {
[INFO] [stderr]     |    ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `arr_slice` is never used
[INFO] [stderr]    --> src/main.rs:183:4
[INFO] [stderr]     |
[INFO] [stderr] 183 | fn arr_slice() {
[INFO] [stderr]     |    ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `test_struct` is never used
[INFO] [stderr]    --> src/main.rs:189:4
[INFO] [stderr]     |
[INFO] [stderr] 189 | fn test_struct (){
[INFO] [stderr]     |    ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `tuple_struct` is never used
[INFO] [stderr]    --> src/main.rs:207:4
[INFO] [stderr]     |
[INFO] [stderr] 207 | fn tuple_struct(){
[INFO] [stderr]     |    ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `unit_like_struct` is never used
[INFO] [stderr]    --> src/main.rs:214:4
[INFO] [stderr]     |
[INFO] [stderr] 214 | fn unit_like_struct() {
[INFO] [stderr]     |    ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: enum `MyOption` is never used
[INFO] [stderr]    --> src/main.rs:275:6
[INFO] [stderr]     |
[INFO] [stderr] 275 | enum MyOption<T> {
[INFO] [stderr]     |      ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: enum `Result` is never used
[INFO] [stderr]    --> src/main.rs:280:6
[INFO] [stderr]     |
[INFO] [stderr] 280 | enum Result<T, E> {
[INFO] [stderr]     |      ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `test3` is never used
[INFO] [stderr]    --> src/main.rs:286:4
[INFO] [stderr]     |
[INFO] [stderr] 286 | fn test3() -> usize {
[INFO] [stderr]     |    ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `Val` is never constructed
[INFO] [stderr]    --> src/main.rs:299:8
[INFO] [stderr]     |
[INFO] [stderr] 299 | struct Val<T> {
[INFO] [stderr]     |        ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method `value` is never used
[INFO] [stderr]    --> src/main.rs:304:8
[INFO] [stderr]     |
[INFO] [stderr] 303 | impl<T> Val<T> {
[INFO] [stderr]     | -------------- method in this implementation
[INFO] [stderr] 304 |     fn value(&self) -> &T {
[INFO] [stderr]     |        ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `sum2` is never used
[INFO] [stderr]    --> src/main.rs:342:4
[INFO] [stderr]     |
[INFO] [stderr] 342 | fn sum2<T: std::ops::Add<Output=T>>(x: T, y: T) -> T
[INFO] [stderr]     |    ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function `new` is never used
[INFO] [stderr]    --> src/main.rs:355:8
[INFO] [stderr]     |
[INFO] [stderr] 354 | impl<T> Pair<T> {
[INFO] [stderr]     | --------------- associated function in this implementation
[INFO] [stderr] 355 |     fn new(x: T, y: T) -> Self {
[INFO] [stderr]     |        ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method `fly` is never used
[INFO] [stderr]    --> src/main.rs:465:8
[INFO] [stderr]     |
[INFO] [stderr] 464 | impl Swan {
[INFO] [stderr]     | --------- method in this implementation
[INFO] [stderr] 465 |     fn fly(&self) {
[INFO] [stderr]     |        ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `static_dispatch_2` is never used
[INFO] [stderr]    --> src/main.rs:537:4
[INFO] [stderr]     |
[INFO] [stderr] 537 | fn static_dispatch_2<T: Foo>(x: T) {
[INFO] [stderr]     |    ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: trait `MyTrait` is never used
[INFO] [stderr]    --> src/main.rs:547:7
[INFO] [stderr]     |
[INFO] [stderr] 547 | trait MyTrait {
[INFO] [stderr]     |       ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `my_function` is never used
[INFO] [stderr]    --> src/main.rs:562:4
[INFO] [stderr]     |
[INFO] [stderr] 562 | fn my_function(x: impl MyTrait) -> impl MyTrait {
[INFO] [stderr]     |    ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: `hello_world` (bin "hello_world" test) generated 29 warnings (run `cargo fix --bin "hello_world" --tests` to apply 4 suggestions)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.05s
[INFO] [stderr]      Running unittests src/main.rs (/opt/rustwide/target/debug/deps/hello_world-56d7540ae9be07ca)
[INFO] running `Command { std: "docker" "inspect" "0707636d261811d3ff2c0286698e0c495e1b6a5d45ea8a3d4b1c606c032d4712", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0707636d261811d3ff2c0286698e0c495e1b6a5d45ea8a3d4b1c606c032d4712", kill_on_drop: false }`
[INFO] [stdout] 0707636d261811d3ff2c0286698e0c495e1b6a5d45ea8a3d4b1c606c032d4712