[INFO] cloning repository https://github.com/luzeduardo/rust-exercises
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/luzeduardo/rust-exercises" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fluzeduardo%2Frust-exercises", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fluzeduardo%2Frust-exercises'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 5153217609dabf0b3895efa693091e8d0b7cd613
[INFO] checking luzeduardo/rust-exercises against try#8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8 for pr-82565
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fluzeduardo%2Frust-exercises" "/workspace/builds/worker-11/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-11/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/luzeduardo/rust-exercises on toolchain 8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/luzeduardo/rust-exercises
[INFO] finished tweaking git repo https://github.com/luzeduardo/rust-exercises
[INFO] tweaked toml for git repo https://github.com/luzeduardo/rust-exercises written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate git repo https://github.com/luzeduardo/rust-exercises already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "rustops/crates-build-env@sha256:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0bcd65b620ac4332839c27f8ea5befff66c8db22c14d3338c22c3e58567263c7
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "0bcd65b620ac4332839c27f8ea5befff66c8db22c14d3338c22c3e58567263c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0bcd65b620ac4332839c27f8ea5befff66c8db22c14d3338c22c3e58567263c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0bcd65b620ac4332839c27f8ea5befff66c8db22c14d3338c22c3e58567263c7", kill_on_drop: false }`
[INFO] [stdout] 0bcd65b620ac4332839c27f8ea5befff66c8db22c14d3338c22c3e58567263c7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4daff3b3f66c5ae6ba78e0f09ebd7c0b19e0bc1d2fc302da575882095fdf8ffb
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "4daff3b3f66c5ae6ba78e0f09ebd7c0b19e0bc1d2fc302da575882095fdf8ffb", kill_on_drop: false }`
[INFO] [stderr]     Checking exercises v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/main.rs:117:29
[INFO] [stdout]     |
[INFO] [stdout] 117 |         pub spells: Vec<Box<Cast>>,
[INFO] [stdout]     |                             ^^^^ help: use `dyn`: `dyn Cast`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]    --> src/main.rs:493:6
[INFO] [stdout]     |
[INFO] [stdout] 493 |     };
[INFO] [stdout]     |      ^ help: remove this semicolon
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(redundant_semicolons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/main.rs:117:29
[INFO] [stdout]     |
[INFO] [stdout] 117 |         pub spells: Vec<Box<Cast>>,
[INFO] [stdout]     |                             ^^^^ help: use `dyn`: `dyn Cast`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]    --> src/main.rs:493:6
[INFO] [stdout]     |
[INFO] [stdout] 493 |     };
[INFO] [stdout]     |      ^ help: remove this semicolon
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(redundant_semicolons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `character`
[INFO] [stdout]    --> src/main.rs:214:36
[INFO] [stdout]     |
[INFO] [stdout] 214 |     pub fn speak_elvish<T: Elvish>(character: T) -> String {
[INFO] [stdout]     |                                    ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_character`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]    --> src/main.rs:323:9
[INFO] [stdout]     |
[INFO] [stdout] 323 |     let len = String::from("Hola").len();
[INFO] [stdout]     |         ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]    --> src/main.rs:327:9
[INFO] [stdout]     |
[INFO] [stdout] 327 |     let mut a = String::new();
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]    --> src/main.rs:332:9
[INFO] [stdout]     |
[INFO] [stdout] 332 |     let s1 = String::from("raise error if access by index");
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer`
[INFO] [stdout]    --> src/main.rs:479:9
[INFO] [stdout]     |
[INFO] [stdout] 479 |     let integer = Point { x: 1, y: 2 };
[INFO] [stdout]     |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `float`
[INFO] [stdout]    --> src/main.rs:480:9
[INFO] [stdout]     |
[INFO] [stdout] 480 |     let float = Point { x: 1.0, y: 2.1 };
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_float`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer_float`
[INFO] [stdout]    --> src/main.rs:486:9
[INFO] [stdout]     |
[INFO] [stdout] 486 |     let integer_float = AreaGenerics { x: 1, y: 4.5 };
[INFO] [stdout]     |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer_float`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/main.rs:30:27
[INFO] [stdout]    |
[INFO] [stdout] 30 |         fn notifymultiple(item: impl Summary, item2: impl Summary) {}
[INFO] [stdout]    |                           ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> src/main.rs:30:47
[INFO] [stdout]    |
[INFO] [stdout] 30 |         fn notifymultiple(item: impl Summary, item2: impl Summary) {}
[INFO] [stdout]    |                                               ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/main.rs:31:46
[INFO] [stdout]    |
[INFO] [stdout] 31 |         fn notifymultipleverbose<T: Summary>(item: T, item2: T) {}
[INFO] [stdout]    |                                              ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> src/main.rs:31:55
[INFO] [stdout]    |
[INFO] [stdout] 31 |         fn notifymultipleverbose<T: Summary>(item: T, item2: T) {}
[INFO] [stdout]    |                                                       ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/main.rs:32:45
[INFO] [stdout]    |
[INFO] [stdout] 32 |         fn notifymultipleTraitsWithPLusSign(item: impl Summary + Display) {}
[INFO] [stdout]    |                                             ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/main.rs:33:62
[INFO] [stdout]    |
[INFO] [stdout] 33 |         fn notifymultipleverbosetraits<T: Summary + Display>(item: T) {}
[INFO] [stdout]    |                                                              ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/main.rs:35:43
[INFO] [stdout]    |
[INFO] [stdout] 35 |         fn notify_with_where_clause<T, U>(t: T, u: U)
[INFO] [stdout]    |                                           ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> src/main.rs:35:49
[INFO] [stdout]    |
[INFO] [stdout] 35 |         fn notify_with_where_clause<T, U>(t: T, u: U)
[INFO] [stdout]    |                                                 ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:327:9
[INFO] [stdout]     |
[INFO] [stdout] 327 |     let mut a = String::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 is never used: `returns_summarizable`
[INFO] [stdout]   --> src/main.rs:42:8
[INFO] [stdout]    |
[INFO] [stdout] 42 |     fn returns_summarizable() -> impl Summary {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_trait_objects`
[INFO] [stdout]   --> src/main.rs:87:4
[INFO] [stdout]    |
[INFO] [stdout] 87 | fn testing_trait_objects() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_traits`
[INFO] [stdout]    --> src/main.rs:185:4
[INFO] [stdout]     |
[INFO] [stdout] 185 | fn testing_traits() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_hash_map`
[INFO] [stdout]    --> src/main.rs:278:4
[INFO] [stdout]     |
[INFO] [stdout] 278 | fn testing_hash_map() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_internal_representation_of_string`
[INFO] [stdout]    --> src/main.rs:322:4
[INFO] [stdout]     |
[INFO] [stdout] 322 | fn testing_internal_representation_of_string() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_strings`
[INFO] [stdout]    --> src/main.rs:326:4
[INFO] [stdout]     |
[INFO] [stdout] 326 | fn testing_strings() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_vector`
[INFO] [stdout]    --> src/main.rs:347:4
[INFO] [stdout]     |
[INFO] [stdout] 347 | fn testing_vector() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_refactoring_struct_tuples`
[INFO] [stdout]    --> src/main.rs:389:4
[INFO] [stdout]     |
[INFO] [stdout] 389 | fn testing_refactoring_struct_tuples() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `area`
[INFO] [stdout]    --> src/main.rs:407:8
[INFO] [stdout]     |
[INFO] [stdout] 407 |     fn area(&self) -> u32 {
[INFO] [stdout]     |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `square`
[INFO] [stdout]    --> src/main.rs:414:8
[INFO] [stdout]     |
[INFO] [stdout] 414 |     fn square(size: u32) -> Rectangle {
[INFO] [stdout]     |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_dangle_error`
[INFO] [stdout]    --> src/main.rs:422:4
[INFO] [stdout]     |
[INFO] [stdout] 422 | fn testing_dangle_error() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `dangle_error`
[INFO] [stdout]    --> src/main.rs:427:4
[INFO] [stdout]     |
[INFO] [stdout] 427 | fn dangle_error() -> String {
[INFO] [stdout]     |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `area`
[INFO] [stdout]    --> src/main.rs:436:4
[INFO] [stdout]     |
[INFO] [stdout] 436 | fn area(rectangle: &Rectangle) -> u32 {
[INFO] [stdout]     |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_takes_ownership`
[INFO] [stdout]    --> src/main.rs:440:4
[INFO] [stdout]     |
[INFO] [stdout] 440 | fn testing_takes_ownership() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `takes_ownership`
[INFO] [stdout]    --> src/main.rs:450:4
[INFO] [stdout]     |
[INFO] [stdout] 450 | fn takes_ownership(somestring: String) {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `makes_copy`
[INFO] [stdout]    --> src/main.rs:453:4
[INFO] [stdout]     |
[INFO] [stdout] 453 | fn makes_copy(example_integer: u32) {
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_owner_refs`
[INFO] [stdout]    --> src/main.rs:457:4
[INFO] [stdout]     |
[INFO] [stdout] 457 | fn testing_owner_refs() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_structs`
[INFO] [stdout]    --> src/main.rs:474:4
[INFO] [stdout]     |
[INFO] [stdout] 474 | fn testing_structs() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `first_word`
[INFO] [stdout]    --> src/main.rs:506:4
[INFO] [stdout]     |
[INFO] [stdout] 506 | fn first_word(s: &str) -> &str {
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `change`
[INFO] [stdout]    --> src/main.rs:516:4
[INFO] [stdout]     |
[INFO] [stdout] 516 | fn change(s: &mut String) {
[INFO] [stdout]     |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `calculate_length_with_reference`
[INFO] [stdout]    --> src/main.rs:520:4
[INFO] [stdout]     |
[INFO] [stdout] 520 | fn calculate_length_with_reference(s: &String) -> usize {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `gives_ownership`
[INFO] [stdout]    --> src/main.rs:524:4
[INFO] [stdout]     |
[INFO] [stdout] 524 | fn gives_ownership() -> String {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `takes_and_gives_back_ownership`
[INFO] [stdout]    --> src/main.rs:529:4
[INFO] [stdout]     |
[INFO] [stdout] 529 | fn takes_and_gives_back_ownership(a_string: String) -> String {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait method `notifymultipleTraitsWithPLusSign` should have a snake case name
[INFO] [stdout]   --> src/main.rs:32:12
[INFO] [stdout]    |
[INFO] [stdout] 32 |         fn notifymultipleTraitsWithPLusSign(item: impl Summary + Display) {}
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert the identifier to snake case: `notifymultiple_traits_with_plus_sign`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `character`
[INFO] [stdout]    --> src/main.rs:214:36
[INFO] [stdout]     |
[INFO] [stdout] 214 |     pub fn speak_elvish<T: Elvish>(character: T) -> String {
[INFO] [stdout]     |                                    ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_character`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 42 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]    --> src/main.rs:323:9
[INFO] [stdout]     |
[INFO] [stdout] 323 |     let len = String::from("Hola").len();
[INFO] [stdout]     |         ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]    --> src/main.rs:327:9
[INFO] [stdout]     |
[INFO] [stdout] 327 |     let mut a = String::new();
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]    --> src/main.rs:332:9
[INFO] [stdout]     |
[INFO] [stdout] 332 |     let s1 = String::from("raise error if access by index");
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer`
[INFO] [stdout]    --> src/main.rs:479:9
[INFO] [stdout]     |
[INFO] [stdout] 479 |     let integer = Point { x: 1, y: 2 };
[INFO] [stdout]     |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `float`
[INFO] [stdout]    --> src/main.rs:480:9
[INFO] [stdout]     |
[INFO] [stdout] 480 |     let float = Point { x: 1.0, y: 2.1 };
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_float`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer_float`
[INFO] [stdout]    --> src/main.rs:486:9
[INFO] [stdout]     |
[INFO] [stdout] 486 |     let integer_float = AreaGenerics { x: 1, y: 4.5 };
[INFO] [stdout]     |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer_float`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/main.rs:30:27
[INFO] [stdout]    |
[INFO] [stdout] 30 |         fn notifymultiple(item: impl Summary, item2: impl Summary) {}
[INFO] [stdout]    |                           ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> src/main.rs:30:47
[INFO] [stdout]    |
[INFO] [stdout] 30 |         fn notifymultiple(item: impl Summary, item2: impl Summary) {}
[INFO] [stdout]    |                                               ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/main.rs:31:46
[INFO] [stdout]    |
[INFO] [stdout] 31 |         fn notifymultipleverbose<T: Summary>(item: T, item2: T) {}
[INFO] [stdout]    |                                              ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item2`
[INFO] [stdout]   --> src/main.rs:31:55
[INFO] [stdout]    |
[INFO] [stdout] 31 |         fn notifymultipleverbose<T: Summary>(item: T, item2: T) {}
[INFO] [stdout]    |                                                       ^^^^^ help: if this is intentional, prefix it with an underscore: `_item2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/main.rs:32:45
[INFO] [stdout]    |
[INFO] [stdout] 32 |         fn notifymultipleTraitsWithPLusSign(item: impl Summary + Display) {}
[INFO] [stdout]    |                                             ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `item`
[INFO] [stdout]   --> src/main.rs:33:62
[INFO] [stdout]    |
[INFO] [stdout] 33 |         fn notifymultipleverbosetraits<T: Summary + Display>(item: T) {}
[INFO] [stdout]    |                                                              ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/main.rs:35:43
[INFO] [stdout]    |
[INFO] [stdout] 35 |         fn notify_with_where_clause<T, U>(t: T, u: U)
[INFO] [stdout]    |                                           ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> src/main.rs:35:49
[INFO] [stdout]    |
[INFO] [stdout] 35 |         fn notify_with_where_clause<T, U>(t: T, u: U)
[INFO] [stdout]    |                                                 ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:327:9
[INFO] [stdout]     |
[INFO] [stdout] 327 |     let mut a = String::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 is never used: `returns_summarizable`
[INFO] [stdout]   --> src/main.rs:42:8
[INFO] [stdout]    |
[INFO] [stdout] 42 |     fn returns_summarizable() -> impl Summary {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_trait_objects`
[INFO] [stdout]   --> src/main.rs:87:4
[INFO] [stdout]    |
[INFO] [stdout] 87 | fn testing_trait_objects() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_traits`
[INFO] [stdout]    --> src/main.rs:185:4
[INFO] [stdout]     |
[INFO] [stdout] 185 | fn testing_traits() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_hash_map`
[INFO] [stdout]    --> src/main.rs:278:4
[INFO] [stdout]     |
[INFO] [stdout] 278 | fn testing_hash_map() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_internal_representation_of_string`
[INFO] [stdout]    --> src/main.rs:322:4
[INFO] [stdout]     |
[INFO] [stdout] 322 | fn testing_internal_representation_of_string() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_strings`
[INFO] [stdout]    --> src/main.rs:326:4
[INFO] [stdout]     |
[INFO] [stdout] 326 | fn testing_strings() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_vector`
[INFO] [stdout]    --> src/main.rs:347:4
[INFO] [stdout]     |
[INFO] [stdout] 347 | fn testing_vector() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_refactoring_struct_tuples`
[INFO] [stdout]    --> src/main.rs:389:4
[INFO] [stdout]     |
[INFO] [stdout] 389 | fn testing_refactoring_struct_tuples() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `area`
[INFO] [stdout]    --> src/main.rs:407:8
[INFO] [stdout]     |
[INFO] [stdout] 407 |     fn area(&self) -> u32 {
[INFO] [stdout]     |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `square`
[INFO] [stdout]    --> src/main.rs:414:8
[INFO] [stdout]     |
[INFO] [stdout] 414 |     fn square(size: u32) -> Rectangle {
[INFO] [stdout]     |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_dangle_error`
[INFO] [stdout]    --> src/main.rs:422:4
[INFO] [stdout]     |
[INFO] [stdout] 422 | fn testing_dangle_error() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `dangle_error`
[INFO] [stdout]    --> src/main.rs:427:4
[INFO] [stdout]     |
[INFO] [stdout] 427 | fn dangle_error() -> String {
[INFO] [stdout]     |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `area`
[INFO] [stdout]    --> src/main.rs:436:4
[INFO] [stdout]     |
[INFO] [stdout] 436 | fn area(rectangle: &Rectangle) -> u32 {
[INFO] [stdout]     |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_takes_ownership`
[INFO] [stdout]    --> src/main.rs:440:4
[INFO] [stdout]     |
[INFO] [stdout] 440 | fn testing_takes_ownership() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `takes_ownership`
[INFO] [stdout]    --> src/main.rs:450:4
[INFO] [stdout]     |
[INFO] [stdout] 450 | fn takes_ownership(somestring: String) {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `makes_copy`
[INFO] [stdout]    --> src/main.rs:453:4
[INFO] [stdout]     |
[INFO] [stdout] 453 | fn makes_copy(example_integer: u32) {
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_owner_refs`
[INFO] [stdout]    --> src/main.rs:457:4
[INFO] [stdout]     |
[INFO] [stdout] 457 | fn testing_owner_refs() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `testing_structs`
[INFO] [stdout]    --> src/main.rs:474:4
[INFO] [stdout]     |
[INFO] [stdout] 474 | fn testing_structs() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `first_word`
[INFO] [stdout]    --> src/main.rs:506:4
[INFO] [stdout]     |
[INFO] [stdout] 506 | fn first_word(s: &str) -> &str {
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `change`
[INFO] [stdout]    --> src/main.rs:516:4
[INFO] [stdout]     |
[INFO] [stdout] 516 | fn change(s: &mut String) {
[INFO] [stdout]     |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `calculate_length_with_reference`
[INFO] [stdout]    --> src/main.rs:520:4
[INFO] [stdout]     |
[INFO] [stdout] 520 | fn calculate_length_with_reference(s: &String) -> usize {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `gives_ownership`
[INFO] [stdout]    --> src/main.rs:524:4
[INFO] [stdout]     |
[INFO] [stdout] 524 | fn gives_ownership() -> String {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `takes_and_gives_back_ownership`
[INFO] [stdout]    --> src/main.rs:529:4
[INFO] [stdout]     |
[INFO] [stdout] 529 | fn takes_and_gives_back_ownership(a_string: String) -> String {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait method `notifymultipleTraitsWithPLusSign` should have a snake case name
[INFO] [stdout]   --> src/main.rs:32:12
[INFO] [stdout]    |
[INFO] [stdout] 32 |         fn notifymultipleTraitsWithPLusSign(item: impl Summary + Display) {}
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert the identifier to snake case: `notifymultiple_traits_with_plus_sign`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 42 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.95s
[INFO] running `Command { std: "docker" "inspect" "4daff3b3f66c5ae6ba78e0f09ebd7c0b19e0bc1d2fc302da575882095fdf8ffb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4daff3b3f66c5ae6ba78e0f09ebd7c0b19e0bc1d2fc302da575882095fdf8ffb", kill_on_drop: false }`
[INFO] [stdout] 4daff3b3f66c5ae6ba78e0f09ebd7c0b19e0bc1d2fc302da575882095fdf8ffb