[INFO] cloning repository https://github.com/jheloper/rust-playground
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jheloper/rust-playground" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjheloper%2Frust-playground"`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjheloper%2Frust-playground'...
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 491b964c424a527ce070fbe760b201e4514f7d2d
[INFO] testing jheloper/rust-playground against beta-2020-06-03 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjheloper%2Frust-playground" "/workspace/builds/worker-4/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jheloper/rust-playground on toolchain beta-2020-06-03
[INFO] running `"/workspace/cargo-home/bin/cargo" "+beta-2020-06-03" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/jheloper/rust-playground
[INFO] finished tweaking git repo https://github.com/jheloper/rust-playground
[INFO] tweaked toml for git repo https://github.com/jheloper/rust-playground written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/jheloper/rust-playground already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+beta-2020-06-03" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-06-03" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 4a4493ce297e6548d455933d1d2a29d1d11d937a25f1c5cb9994744e90da6c76
[INFO] running `"docker" "start" "-a" "4a4493ce297e6548d455933d1d2a29d1d11d937a25f1c5cb9994744e90da6c76"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling rust-playground v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/function_example.rs:17:9
[INFO] [stderr]    |
[INFO] [stderr] 17 |     let x = 10;
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `reference_to_nothing`
[INFO] [stderr]   --> src/reference_example.rs:45:9
[INFO] [stderr]    |
[INFO] [stderr] 45 |     let reference_to_nothing = no_dangle();
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_reference_to_nothing`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `some_string`
[INFO] [stderr]   --> src/reference_example.rs:53:11
[INFO] [stderr]    |
[INFO] [stderr] 53 | fn change(some_string: &String) {
[INFO] [stderr]    |           ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `vector1`
[INFO] [stderr]  --> src/collection_example.rs:4:9
[INFO] [stderr]   |
[INFO] [stderr] 4 |     let vector1: Vec<i32> = Vec::new();
[INFO] [stderr]   |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_vector1`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `string1`
[INFO] [stderr]   --> src/collection_example.rs:59:9
[INFO] [stderr]    |
[INFO] [stderr] 59 |     let mut string1 = String::new();
[INFO] [stderr]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_string1`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `f`
[INFO] [stderr]   --> src/error_example.rs:16:9
[INFO] [stderr]    |
[INFO] [stderr] 16 |     let f = match f {
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `guess1`
[INFO] [stderr]   --> src/error_example.rs:41:9
[INFO] [stderr]    |
[INFO] [stderr] 41 |     let guess1 = Guess::new(101);
[INFO] [stderr]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_guess1`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/reference_example.rs:35:9
[INFO] [stderr]    |
[INFO] [stderr] 35 |     let mut s6 = String::from("hello");
[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: variable does not need to be mutable
[INFO] [stderr]   --> src/collection_example.rs:34:9
[INFO] [stderr]    |
[INFO] [stderr] 34 |     let mut vector4 = vec![1, 2, 3, 4, 5];
[INFO] [stderr]    |         ----^^^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/collection_example.rs:59:9
[INFO] [stderr]    |
[INFO] [stderr] 59 |     let mut string1 = String::new();
[INFO] [stderr]    |         ----^^^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_variable_and_mutability`
[INFO] [stderr]  --> src/variable_and_mutability_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_variable_and_mutability() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_data_type`
[INFO] [stderr]  --> src/data_type_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_data_type() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_function`
[INFO] [stderr]  --> src/function_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_function() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `another_function`
[INFO] [stderr]  --> src/function_example.rs:9:4
[INFO] [stderr]   |
[INFO] [stderr] 9 | fn another_function(x: i32, y: i32) {
[INFO] [stderr]   |    ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `block_expression`
[INFO] [stderr]   --> src/function_example.rs:16:4
[INFO] [stderr]    |
[INFO] [stderr] 16 | fn block_expression() {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `return_ten`
[INFO] [stderr]   --> src/function_example.rs:27:4
[INFO] [stderr]    |
[INFO] [stderr] 27 | fn return_ten() -> i32 {
[INFO] [stderr]    |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_control_flow`
[INFO] [stderr]  --> src/control_flow_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_control_flow() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_module`
[INFO] [stderr]  --> src/module_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_module() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_ownership`
[INFO] [stderr]  --> src/ownership_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_ownership() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `takes_ownership`
[INFO] [stderr]   --> src/ownership_example.rs:47:4
[INFO] [stderr]    |
[INFO] [stderr] 47 | fn takes_ownership(some_string: String) {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `makes_copy`
[INFO] [stderr]   --> src/ownership_example.rs:51:4
[INFO] [stderr]    |
[INFO] [stderr] 51 | fn makes_copy(some_integer: i32) {
[INFO] [stderr]    |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `gives_ownership`
[INFO] [stderr]   --> src/ownership_example.rs:55:4
[INFO] [stderr]    |
[INFO] [stderr] 55 | fn gives_ownership() -> String {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `takes_and_gives_back`
[INFO] [stderr]   --> src/ownership_example.rs:60:4
[INFO] [stderr]    |
[INFO] [stderr] 60 | fn takes_and_gives_back(a_string: String) -> String {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_reference`
[INFO] [stderr]  --> src/reference_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_reference() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `calculate_length`
[INFO] [stderr]   --> src/reference_example.rs:48:4
[INFO] [stderr]    |
[INFO] [stderr] 48 | fn calculate_length(s: &String) -> usize {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `change`
[INFO] [stderr]   --> src/reference_example.rs:53:4
[INFO] [stderr]    |
[INFO] [stderr] 53 | fn change(some_string: &String) {
[INFO] [stderr]    |    ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `change_mutable`
[INFO] [stderr]   --> src/reference_example.rs:58:4
[INFO] [stderr]    |
[INFO] [stderr] 58 | fn change_mutable(some_string: &mut String) {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `no_dangle`
[INFO] [stderr]   --> src/reference_example.rs:68:4
[INFO] [stderr]    |
[INFO] [stderr] 68 | fn no_dangle() -> String {
[INFO] [stderr]    |    ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_slices`
[INFO] [stderr]  --> src/slice_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_slices() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `first_word`
[INFO] [stderr]   --> src/slice_example.rs:45:4
[INFO] [stderr]    |
[INFO] [stderr] 45 | fn first_word(s: &String) -> usize {
[INFO] [stderr]    |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `first_word_slices`
[INFO] [stderr]   --> src/slice_example.rs:58:4
[INFO] [stderr]    |
[INFO] [stderr] 58 | fn first_word_slices(s: &str) -> &str {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `second_word_slices`
[INFO] [stderr]   --> src/slice_example.rs:71:4
[INFO] [stderr]    |
[INFO] [stderr] 71 | fn second_word_slices(s: &str) -> &str {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_struct`
[INFO] [stderr]  --> src/struct_example.rs:9:8
[INFO] [stderr]   |
[INFO] [stderr] 9 | pub fn example_struct() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `build_user`
[INFO] [stderr]   --> src/struct_example.rs:41:4
[INFO] [stderr]    |
[INFO] [stderr] 41 | fn build_user(email: String, username: String) -> User {
[INFO] [stderr]    |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_tuple_struct`
[INFO] [stderr]   --> src/struct_example.rs:57:4
[INFO] [stderr]    |
[INFO] [stderr] 57 | fn example_tuple_struct() {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_struct_rectangles`
[INFO] [stderr]  --> src/struct_rectangles_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_struct_rectangles() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `calculate_area`
[INFO] [stderr]   --> src/struct_rectangles_example.rs:29:4
[INFO] [stderr]    |
[INFO] [stderr] 29 | fn calculate_area(length: u32, width: u32) -> u32 {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `calculate_area_by_tuple`
[INFO] [stderr]   --> src/struct_rectangles_example.rs:33:4
[INFO] [stderr]    |
[INFO] [stderr] 33 | fn calculate_area_by_tuple(dimensions: (u32, u32)) -> u32 {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `calculate_area_by_struct`
[INFO] [stderr]   --> src/struct_rectangles_example.rs:45:4
[INFO] [stderr]    |
[INFO] [stderr] 45 | fn calculate_area_by_struct(rectangle: &Rectangle) -> u32 {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Rectangle`
[INFO] [stderr]  --> src/method_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | struct Rectangle {
[INFO] [stderr]   |        ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `calculate_area`
[INFO] [stderr]  --> src/method_example.rs:7:8
[INFO] [stderr]   |
[INFO] [stderr] 7 |     fn calculate_area(&self) -> u32 {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `can_hold`
[INFO] [stderr]   --> src/method_example.rs:11:8
[INFO] [stderr]    |
[INFO] [stderr] 11 |     fn can_hold(&self, other: &Rectangle) -> bool {
[INFO] [stderr]    |        ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `square`
[INFO] [stderr]   --> src/method_example.rs:15:8
[INFO] [stderr]    |
[INFO] [stderr] 15 |     fn square(size: u32) -> Rectangle {
[INFO] [stderr]    |        ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_method`
[INFO] [stderr]   --> src/method_example.rs:23:8
[INFO] [stderr]    |
[INFO] [stderr] 23 | pub fn example_method() {
[INFO] [stderr]    |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_enums`
[INFO] [stderr]  --> src/enums_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_enums() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `V4`
[INFO] [stderr]   --> src/enums_example.rs:57:5
[INFO] [stderr]    |
[INFO] [stderr] 57 |     V4,
[INFO] [stderr]    |     ^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `V6`
[INFO] [stderr]   --> src/enums_example.rs:58:5
[INFO] [stderr]    |
[INFO] [stderr] 58 |     V6,
[INFO] [stderr]    |     ^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `V4`
[INFO] [stderr]   --> src/enums_example.rs:69:5
[INFO] [stderr]    |
[INFO] [stderr] 69 |     V4(u8, u8, u8, u8),
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `V6`
[INFO] [stderr]   --> src/enums_example.rs:70:5
[INFO] [stderr]    |
[INFO] [stderr] 70 |     V6(String),
[INFO] [stderr]    |     ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Quit`
[INFO] [stderr]   --> src/enums_example.rs:75:5
[INFO] [stderr]    |
[INFO] [stderr] 75 |     Quit,
[INFO] [stderr]    |     ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Move`
[INFO] [stderr]   --> src/enums_example.rs:76:5
[INFO] [stderr]    |
[INFO] [stderr] 76 |     Move { x: i32, y: i32 },
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Write`
[INFO] [stderr]   --> src/enums_example.rs:77:5
[INFO] [stderr]    |
[INFO] [stderr] 77 |     Write(String),
[INFO] [stderr]    |     ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `ChangeColor`
[INFO] [stderr]   --> src/enums_example.rs:78:5
[INFO] [stderr]    |
[INFO] [stderr] 78 |     ChangeColor(i32, i32, i32),
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `call`
[INFO] [stderr]   --> src/enums_example.rs:82:8
[INFO] [stderr]    |
[INFO] [stderr] 82 |     fn call(&self) {
[INFO] [stderr]    |        ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_match`
[INFO] [stderr]  --> src/match_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_match() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Alabama`
[INFO] [stderr]   --> src/match_example.rs:50:5
[INFO] [stderr]    |
[INFO] [stderr] 50 |     Alabama,
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Alaska`
[INFO] [stderr]   --> src/match_example.rs:51:5
[INFO] [stderr]    |
[INFO] [stderr] 51 |     Alaska,
[INFO] [stderr]    |     ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Washington`
[INFO] [stderr]   --> src/match_example.rs:52:5
[INFO] [stderr]    |
[INFO] [stderr] 52 |     Washington,
[INFO] [stderr]    |     ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Ohio`
[INFO] [stderr]   --> src/match_example.rs:53:5
[INFO] [stderr]    |
[INFO] [stderr] 53 |     Ohio,
[INFO] [stderr]    |     ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: enum is never used: `Coin`
[INFO] [stderr]   --> src/match_example.rs:56:6
[INFO] [stderr]    |
[INFO] [stderr] 56 | enum Coin {
[INFO] [stderr]    |      ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `value_in_cents`
[INFO] [stderr]   --> src/match_example.rs:63:4
[INFO] [stderr]    |
[INFO] [stderr] 63 | fn value_in_cents(coin: Coin) -> u32 {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `plus_one`
[INFO] [stderr]   --> src/match_example.rs:78:4
[INFO] [stderr]    |
[INFO] [stderr] 78 | fn plus_one(x: Option<i32>) -> Option<i32> {
[INFO] [stderr]    |    ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_collection`
[INFO] [stderr]  --> src/collection_example.rs:3:8
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub fn example_collection() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Int`
[INFO] [stderr]    --> src/collection_example.rs:169:5
[INFO] [stderr]     |
[INFO] [stderr] 169 |     Int(i32),
[INFO] [stderr]     |     ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Float`
[INFO] [stderr]    --> src/collection_example.rs:170:5
[INFO] [stderr]     |
[INFO] [stderr] 170 |     Float(f64),
[INFO] [stderr]     |     ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Text`
[INFO] [stderr]    --> src/collection_example.rs:171:5
[INFO] [stderr]     |
[INFO] [stderr] 171 |     Text(String),
[INFO] [stderr]     |     ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_error`
[INFO] [stderr]  --> src/error_example.rs:6:8
[INFO] [stderr]   |
[INFO] [stderr] 6 | pub fn example_error() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `read_username_from_file`
[INFO] [stderr]   --> src/error_example.rs:48:4
[INFO] [stderr]    |
[INFO] [stderr] 48 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `read_username_from_file2`
[INFO] [stderr]   --> src/error_example.rs:63:4
[INFO] [stderr]    |
[INFO] [stderr] 63 | fn read_username_from_file2() -> Result<String, io::Error> {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Guess`
[INFO] [stderr]   --> src/error_example.rs:76:12
[INFO] [stderr]    |
[INFO] [stderr] 76 | pub struct Guess {
[INFO] [stderr]    |            ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `new`
[INFO] [stderr]   --> src/error_example.rs:81:12
[INFO] [stderr]    |
[INFO] [stderr] 81 |     pub fn new(value: u32) -> Guess {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `value`
[INFO] [stderr]   --> src/error_example.rs:89:12
[INFO] [stderr]    |
[INFO] [stderr] 89 |     pub fn value(&self) -> u32 {
[INFO] [stderr]    |            ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_generic`
[INFO] [stderr]  --> src/generic_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_generic() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `largest`
[INFO] [stderr]   --> src/generic_example.rs:44:4
[INFO] [stderr]    |
[INFO] [stderr] 44 | fn largest(list: &[i32]) -> i32 {
[INFO] [stderr]    |    ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `largest_i32`
[INFO] [stderr]   --> src/generic_example.rs:56:4
[INFO] [stderr]    |
[INFO] [stderr] 56 | fn largest_i32(list: &[i32]) -> i32 {
[INFO] [stderr]    |    ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `largest_char`
[INFO] [stderr]   --> src/generic_example.rs:68:4
[INFO] [stderr]    |
[INFO] [stderr] 68 | fn largest_char(list: &[char]) -> char {
[INFO] [stderr]    |    ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `x`
[INFO] [stderr]   --> src/generic_example.rs:87:8
[INFO] [stderr]    |
[INFO] [stderr] 87 |     fn x(&self) -> &T {
[INFO] [stderr]    |        ^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `mixup`
[INFO] [stderr]   --> src/generic_example.rs:99:8
[INFO] [stderr]    |
[INFO] [stderr] 99 |     fn mixup<V, W>(self, other: Point2<V, W>) -> Point2<T, W> {
[INFO] [stderr]    |        ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 78 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.18s
[INFO] running `"docker" "inspect" "4a4493ce297e6548d455933d1d2a29d1d11d937a25f1c5cb9994744e90da6c76"`
[INFO] running `"docker" "rm" "-f" "4a4493ce297e6548d455933d1d2a29d1d11d937a25f1c5cb9994744e90da6c76"`
[INFO] [stdout] 4a4493ce297e6548d455933d1d2a29d1d11d937a25f1c5cb9994744e90da6c76
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-06-03" "test" "--frozen" "--no-run"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 27b8c57d2a3b1b2b95bd0bc96bdb65be4f414e87ed8a5656fff3dc51abe41c13
[INFO] running `"docker" "start" "-a" "27b8c57d2a3b1b2b95bd0bc96bdb65be4f414e87ed8a5656fff3dc51abe41c13"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling rust-playground v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/function_example.rs:17:9
[INFO] [stderr]    |
[INFO] [stderr] 17 |     let x = 10;
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `reference_to_nothing`
[INFO] [stderr]   --> src/reference_example.rs:45:9
[INFO] [stderr]    |
[INFO] [stderr] 45 |     let reference_to_nothing = no_dangle();
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_reference_to_nothing`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `some_string`
[INFO] [stderr]   --> src/reference_example.rs:53:11
[INFO] [stderr]    |
[INFO] [stderr] 53 | fn change(some_string: &String) {
[INFO] [stderr]    |           ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `vector1`
[INFO] [stderr]  --> src/collection_example.rs:4:9
[INFO] [stderr]   |
[INFO] [stderr] 4 |     let vector1: Vec<i32> = Vec::new();
[INFO] [stderr]   |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_vector1`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `string1`
[INFO] [stderr]   --> src/collection_example.rs:59:9
[INFO] [stderr]    |
[INFO] [stderr] 59 |     let mut string1 = String::new();
[INFO] [stderr]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_string1`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `f`
[INFO] [stderr]   --> src/error_example.rs:16:9
[INFO] [stderr]    |
[INFO] [stderr] 16 |     let f = match f {
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `guess1`
[INFO] [stderr]   --> src/error_example.rs:41:9
[INFO] [stderr]    |
[INFO] [stderr] 41 |     let guess1 = Guess::new(101);
[INFO] [stderr]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_guess1`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/reference_example.rs:35:9
[INFO] [stderr]    |
[INFO] [stderr] 35 |     let mut s6 = String::from("hello");
[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: variable does not need to be mutable
[INFO] [stderr]   --> src/collection_example.rs:34:9
[INFO] [stderr]    |
[INFO] [stderr] 34 |     let mut vector4 = vec![1, 2, 3, 4, 5];
[INFO] [stderr]    |         ----^^^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/collection_example.rs:59:9
[INFO] [stderr]    |
[INFO] [stderr] 59 |     let mut string1 = String::new();
[INFO] [stderr]    |         ----^^^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_variable_and_mutability`
[INFO] [stderr]  --> src/variable_and_mutability_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_variable_and_mutability() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_data_type`
[INFO] [stderr]  --> src/data_type_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_data_type() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_function`
[INFO] [stderr]  --> src/function_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_function() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `another_function`
[INFO] [stderr]  --> src/function_example.rs:9:4
[INFO] [stderr]   |
[INFO] [stderr] 9 | fn another_function(x: i32, y: i32) {
[INFO] [stderr]   |    ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `block_expression`
[INFO] [stderr]   --> src/function_example.rs:16:4
[INFO] [stderr]    |
[INFO] [stderr] 16 | fn block_expression() {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `return_ten`
[INFO] [stderr]   --> src/function_example.rs:27:4
[INFO] [stderr]    |
[INFO] [stderr] 27 | fn return_ten() -> i32 {
[INFO] [stderr]    |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_control_flow`
[INFO] [stderr]  --> src/control_flow_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_control_flow() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_module`
[INFO] [stderr]  --> src/module_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_module() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_ownership`
[INFO] [stderr]  --> src/ownership_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_ownership() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `takes_ownership`
[INFO] [stderr]   --> src/ownership_example.rs:47:4
[INFO] [stderr]    |
[INFO] [stderr] 47 | fn takes_ownership(some_string: String) {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `makes_copy`
[INFO] [stderr]   --> src/ownership_example.rs:51:4
[INFO] [stderr]    |
[INFO] [stderr] 51 | fn makes_copy(some_integer: i32) {
[INFO] [stderr]    |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `gives_ownership`
[INFO] [stderr]   --> src/ownership_example.rs:55:4
[INFO] [stderr]    |
[INFO] [stderr] 55 | fn gives_ownership() -> String {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `takes_and_gives_back`
[INFO] [stderr]   --> src/ownership_example.rs:60:4
[INFO] [stderr]    |
[INFO] [stderr] 60 | fn takes_and_gives_back(a_string: String) -> String {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_reference`
[INFO] [stderr]  --> src/reference_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_reference() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `calculate_length`
[INFO] [stderr]   --> src/reference_example.rs:48:4
[INFO] [stderr]    |
[INFO] [stderr] 48 | fn calculate_length(s: &String) -> usize {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `change`
[INFO] [stderr]   --> src/reference_example.rs:53:4
[INFO] [stderr]    |
[INFO] [stderr] 53 | fn change(some_string: &String) {
[INFO] [stderr]    |    ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `change_mutable`
[INFO] [stderr]   --> src/reference_example.rs:58:4
[INFO] [stderr]    |
[INFO] [stderr] 58 | fn change_mutable(some_string: &mut String) {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `no_dangle`
[INFO] [stderr]   --> src/reference_example.rs:68:4
[INFO] [stderr]    |
[INFO] [stderr] 68 | fn no_dangle() -> String {
[INFO] [stderr]    |    ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_slices`
[INFO] [stderr]  --> src/slice_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_slices() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `first_word`
[INFO] [stderr]   --> src/slice_example.rs:45:4
[INFO] [stderr]    |
[INFO] [stderr] 45 | fn first_word(s: &String) -> usize {
[INFO] [stderr]    |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `first_word_slices`
[INFO] [stderr]   --> src/slice_example.rs:58:4
[INFO] [stderr]    |
[INFO] [stderr] 58 | fn first_word_slices(s: &str) -> &str {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `second_word_slices`
[INFO] [stderr]   --> src/slice_example.rs:71:4
[INFO] [stderr]    |
[INFO] [stderr] 71 | fn second_word_slices(s: &str) -> &str {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_struct`
[INFO] [stderr]  --> src/struct_example.rs:9:8
[INFO] [stderr]   |
[INFO] [stderr] 9 | pub fn example_struct() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `build_user`
[INFO] [stderr]   --> src/struct_example.rs:41:4
[INFO] [stderr]    |
[INFO] [stderr] 41 | fn build_user(email: String, username: String) -> User {
[INFO] [stderr]    |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_tuple_struct`
[INFO] [stderr]   --> src/struct_example.rs:57:4
[INFO] [stderr]    |
[INFO] [stderr] 57 | fn example_tuple_struct() {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_struct_rectangles`
[INFO] [stderr]  --> src/struct_rectangles_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_struct_rectangles() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `calculate_area`
[INFO] [stderr]   --> src/struct_rectangles_example.rs:29:4
[INFO] [stderr]    |
[INFO] [stderr] 29 | fn calculate_area(length: u32, width: u32) -> u32 {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `calculate_area_by_tuple`
[INFO] [stderr]   --> src/struct_rectangles_example.rs:33:4
[INFO] [stderr]    |
[INFO] [stderr] 33 | fn calculate_area_by_tuple(dimensions: (u32, u32)) -> u32 {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `calculate_area_by_struct`
[INFO] [stderr]   --> src/struct_rectangles_example.rs:45:4
[INFO] [stderr]    |
[INFO] [stderr] 45 | fn calculate_area_by_struct(rectangle: &Rectangle) -> u32 {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Rectangle`
[INFO] [stderr]  --> src/method_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | struct Rectangle {
[INFO] [stderr]   |        ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `calculate_area`
[INFO] [stderr]  --> src/method_example.rs:7:8
[INFO] [stderr]   |
[INFO] [stderr] 7 |     fn calculate_area(&self) -> u32 {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `can_hold`
[INFO] [stderr]   --> src/method_example.rs:11:8
[INFO] [stderr]    |
[INFO] [stderr] 11 |     fn can_hold(&self, other: &Rectangle) -> bool {
[INFO] [stderr]    |        ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `square`
[INFO] [stderr]   --> src/method_example.rs:15:8
[INFO] [stderr]    |
[INFO] [stderr] 15 |     fn square(size: u32) -> Rectangle {
[INFO] [stderr]    |        ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_method`
[INFO] [stderr]   --> src/method_example.rs:23:8
[INFO] [stderr]    |
[INFO] [stderr] 23 | pub fn example_method() {
[INFO] [stderr]    |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_enums`
[INFO] [stderr]  --> src/enums_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_enums() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `V4`
[INFO] [stderr]   --> src/enums_example.rs:57:5
[INFO] [stderr]    |
[INFO] [stderr] 57 |     V4,
[INFO] [stderr]    |     ^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `V6`
[INFO] [stderr]   --> src/enums_example.rs:58:5
[INFO] [stderr]    |
[INFO] [stderr] 58 |     V6,
[INFO] [stderr]    |     ^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `V4`
[INFO] [stderr]   --> src/enums_example.rs:69:5
[INFO] [stderr]    |
[INFO] [stderr] 69 |     V4(u8, u8, u8, u8),
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `V6`
[INFO] [stderr]   --> src/enums_example.rs:70:5
[INFO] [stderr]    |
[INFO] [stderr] 70 |     V6(String),
[INFO] [stderr]    |     ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Quit`
[INFO] [stderr]   --> src/enums_example.rs:75:5
[INFO] [stderr]    |
[INFO] [stderr] 75 |     Quit,
[INFO] [stderr]    |     ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Move`
[INFO] [stderr]   --> src/enums_example.rs:76:5
[INFO] [stderr]    |
[INFO] [stderr] 76 |     Move { x: i32, y: i32 },
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Write`
[INFO] [stderr]   --> src/enums_example.rs:77:5
[INFO] [stderr]    |
[INFO] [stderr] 77 |     Write(String),
[INFO] [stderr]    |     ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `ChangeColor`
[INFO] [stderr]   --> src/enums_example.rs:78:5
[INFO] [stderr]    |
[INFO] [stderr] 78 |     ChangeColor(i32, i32, i32),
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `call`
[INFO] [stderr]   --> src/enums_example.rs:82:8
[INFO] [stderr]    |
[INFO] [stderr] 82 |     fn call(&self) {
[INFO] [stderr]    |        ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_match`
[INFO] [stderr]  --> src/match_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_match() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Alabama`
[INFO] [stderr]   --> src/match_example.rs:50:5
[INFO] [stderr]    |
[INFO] [stderr] 50 |     Alabama,
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Alaska`
[INFO] [stderr]   --> src/match_example.rs:51:5
[INFO] [stderr]    |
[INFO] [stderr] 51 |     Alaska,
[INFO] [stderr]    |     ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Washington`
[INFO] [stderr]   --> src/match_example.rs:52:5
[INFO] [stderr]    |
[INFO] [stderr] 52 |     Washington,
[INFO] [stderr]    |     ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Ohio`
[INFO] [stderr]   --> src/match_example.rs:53:5
[INFO] [stderr]    |
[INFO] [stderr] 53 |     Ohio,
[INFO] [stderr]    |     ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: enum is never used: `Coin`
[INFO] [stderr]   --> src/match_example.rs:56:6
[INFO] [stderr]    |
[INFO] [stderr] 56 | enum Coin {
[INFO] [stderr]    |      ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `value_in_cents`
[INFO] [stderr]   --> src/match_example.rs:63:4
[INFO] [stderr]    |
[INFO] [stderr] 63 | fn value_in_cents(coin: Coin) -> u32 {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `plus_one`
[INFO] [stderr]   --> src/match_example.rs:78:4
[INFO] [stderr]    |
[INFO] [stderr] 78 | fn plus_one(x: Option<i32>) -> Option<i32> {
[INFO] [stderr]    |    ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_collection`
[INFO] [stderr]  --> src/collection_example.rs:3:8
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub fn example_collection() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Int`
[INFO] [stderr]    --> src/collection_example.rs:169:5
[INFO] [stderr]     |
[INFO] [stderr] 169 |     Int(i32),
[INFO] [stderr]     |     ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Float`
[INFO] [stderr]    --> src/collection_example.rs:170:5
[INFO] [stderr]     |
[INFO] [stderr] 170 |     Float(f64),
[INFO] [stderr]     |     ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Text`
[INFO] [stderr]    --> src/collection_example.rs:171:5
[INFO] [stderr]     |
[INFO] [stderr] 171 |     Text(String),
[INFO] [stderr]     |     ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_error`
[INFO] [stderr]  --> src/error_example.rs:6:8
[INFO] [stderr]   |
[INFO] [stderr] 6 | pub fn example_error() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `read_username_from_file`
[INFO] [stderr]   --> src/error_example.rs:48:4
[INFO] [stderr]    |
[INFO] [stderr] 48 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `read_username_from_file2`
[INFO] [stderr]   --> src/error_example.rs:63:4
[INFO] [stderr]    |
[INFO] [stderr] 63 | fn read_username_from_file2() -> Result<String, io::Error> {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Guess`
[INFO] [stderr]   --> src/error_example.rs:76:12
[INFO] [stderr]    |
[INFO] [stderr] 76 | pub struct Guess {
[INFO] [stderr]    |            ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `new`
[INFO] [stderr]   --> src/error_example.rs:81:12
[INFO] [stderr]    |
[INFO] [stderr] 81 |     pub fn new(value: u32) -> Guess {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `value`
[INFO] [stderr]   --> src/error_example.rs:89:12
[INFO] [stderr]    |
[INFO] [stderr] 89 |     pub fn value(&self) -> u32 {
[INFO] [stderr]    |            ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_generic`
[INFO] [stderr]  --> src/generic_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_generic() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `largest`
[INFO] [stderr]   --> src/generic_example.rs:44:4
[INFO] [stderr]    |
[INFO] [stderr] 44 | fn largest(list: &[i32]) -> i32 {
[INFO] [stderr]    |    ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `largest_i32`
[INFO] [stderr]   --> src/generic_example.rs:56:4
[INFO] [stderr]    |
[INFO] [stderr] 56 | fn largest_i32(list: &[i32]) -> i32 {
[INFO] [stderr]    |    ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `largest_char`
[INFO] [stderr]   --> src/generic_example.rs:68:4
[INFO] [stderr]    |
[INFO] [stderr] 68 | fn largest_char(list: &[char]) -> char {
[INFO] [stderr]    |    ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `x`
[INFO] [stderr]   --> src/generic_example.rs:87:8
[INFO] [stderr]    |
[INFO] [stderr] 87 |     fn x(&self) -> &T {
[INFO] [stderr]    |        ^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `mixup`
[INFO] [stderr]   --> src/generic_example.rs:99:8
[INFO] [stderr]    |
[INFO] [stderr] 99 |     fn mixup<V, W>(self, other: Point2<V, W>) -> Point2<T, W> {
[INFO] [stderr]    |        ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 78 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 1.01s
[INFO] running `"docker" "inspect" "27b8c57d2a3b1b2b95bd0bc96bdb65be4f414e87ed8a5656fff3dc51abe41c13"`
[INFO] running `"docker" "rm" "-f" "27b8c57d2a3b1b2b95bd0bc96bdb65be4f414e87ed8a5656fff3dc51abe41c13"`
[INFO] [stdout] 27b8c57d2a3b1b2b95bd0bc96bdb65be4f414e87ed8a5656fff3dc51abe41c13
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-06-03" "test" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 16ff00de20d8c06b16bfb06a11df5924d18169ae7d624ad402c4d3e94e8ff784
[INFO] running `"docker" "start" "-a" "16ff00de20d8c06b16bfb06a11df5924d18169ae7d624ad402c4d3e94e8ff784"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/function_example.rs:17:9
[INFO] [stderr]    |
[INFO] [stderr] 17 |     let x = 10;
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `reference_to_nothing`
[INFO] [stderr]   --> src/reference_example.rs:45:9
[INFO] [stderr]    |
[INFO] [stderr] 45 |     let reference_to_nothing = no_dangle();
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_reference_to_nothing`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `some_string`
[INFO] [stderr]   --> src/reference_example.rs:53:11
[INFO] [stderr]    |
[INFO] [stderr] 53 | fn change(some_string: &String) {
[INFO] [stderr]    |           ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `vector1`
[INFO] [stderr]  --> src/collection_example.rs:4:9
[INFO] [stderr]   |
[INFO] [stderr] 4 |     let vector1: Vec<i32> = Vec::new();
[INFO] [stderr]   |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_vector1`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `string1`
[INFO] [stderr]   --> src/collection_example.rs:59:9
[INFO] [stderr]    |
[INFO] [stderr] 59 |     let mut string1 = String::new();
[INFO] [stderr]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_string1`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `f`
[INFO] [stderr]   --> src/error_example.rs:16:9
[INFO] [stderr]    |
[INFO] [stderr] 16 |     let f = match f {
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `guess1`
[INFO] [stderr]   --> src/error_example.rs:41:9
[INFO] [stderr]    |
[INFO] [stderr] 41 |     let guess1 = Guess::new(101);
[INFO] [stderr]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_guess1`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/reference_example.rs:35:9
[INFO] [stderr]    |
[INFO] [stderr] 35 |     let mut s6 = String::from("hello");
[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: variable does not need to be mutable
[INFO] [stderr]   --> src/collection_example.rs:34:9
[INFO] [stderr]    |
[INFO] [stderr] 34 |     let mut vector4 = vec![1, 2, 3, 4, 5];
[INFO] [stderr]    |         ----^^^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/collection_example.rs:59:9
[INFO] [stderr]    |
[INFO] [stderr] 59 |     let mut string1 = String::new();
[INFO] [stderr]    |         ----^^^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_variable_and_mutability`
[INFO] [stderr]  --> src/variable_and_mutability_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_variable_and_mutability() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_data_type`
[INFO] [stderr]  --> src/data_type_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_data_type() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_function`
[INFO] [stderr]  --> src/function_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_function() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `another_function`
[INFO] [stderr]  --> src/function_example.rs:9:4
[INFO] [stderr]   |
[INFO] [stderr] 9 | fn another_function(x: i32, y: i32) {
[INFO] [stderr]   |    ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `block_expression`
[INFO] [stderr]   --> src/function_example.rs:16:4
[INFO] [stderr]    |
[INFO] [stderr] 16 | fn block_expression() {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `return_ten`
[INFO] [stderr]   --> src/function_example.rs:27:4
[INFO] [stderr]    |
[INFO] [stderr] 27 | fn return_ten() -> i32 {
[INFO] [stderr]    |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_control_flow`
[INFO] [stderr]  --> src/control_flow_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_control_flow() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_module`
[INFO] [stderr]  --> src/module_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_module() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_ownership`
[INFO] [stderr]  --> src/ownership_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_ownership() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `takes_ownership`
[INFO] [stderr]   --> src/ownership_example.rs:47:4
[INFO] [stderr]    |
[INFO] [stderr] 47 | fn takes_ownership(some_string: String) {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `makes_copy`
[INFO] [stderr]   --> src/ownership_example.rs:51:4
[INFO] [stderr]    |
[INFO] [stderr] 51 | fn makes_copy(some_integer: i32) {
[INFO] [stderr]    |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `gives_ownership`
[INFO] [stderr]   --> src/ownership_example.rs:55:4
[INFO] [stderr]    |
[INFO] [stderr] 55 | fn gives_ownership() -> String {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `takes_and_gives_back`
[INFO] [stderr]   --> src/ownership_example.rs:60:4
[INFO] [stderr]    |
[INFO] [stderr] 60 | fn takes_and_gives_back(a_string: String) -> String {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_reference`
[INFO] [stderr]  --> src/reference_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_reference() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `calculate_length`
[INFO] [stderr]   --> src/reference_example.rs:48:4
[INFO] [stderr]    |
[INFO] [stderr] 48 | fn calculate_length(s: &String) -> usize {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `change`
[INFO] [stderr]   --> src/reference_example.rs:53:4
[INFO] [stderr]    |
[INFO] [stderr] 53 | fn change(some_string: &String) {
[INFO] [stderr]    |    ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `change_mutable`
[INFO] [stderr]   --> src/reference_example.rs:58:4
[INFO] [stderr]    |
[INFO] [stderr] 58 | fn change_mutable(some_string: &mut String) {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `no_dangle`
[INFO] [stderr]   --> src/reference_example.rs:68:4
[INFO] [stderr]    |
[INFO] [stderr] 68 | fn no_dangle() -> String {
[INFO] [stderr]    |    ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_slices`
[INFO] [stderr]  --> src/slice_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_slices() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `first_word`
[INFO] [stderr]   --> src/slice_example.rs:45:4
[INFO] [stderr]    |
[INFO] [stderr] 45 | fn first_word(s: &String) -> usize {
[INFO] [stderr]    |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `first_word_slices`
[INFO] [stderr]   --> src/slice_example.rs:58:4
[INFO] [stderr]    |
[INFO] [stderr] 58 | fn first_word_slices(s: &str) -> &str {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `second_word_slices`
[INFO] [stderr]   --> src/slice_example.rs:71:4
[INFO] [stderr]    |
[INFO] [stderr] 71 | fn second_word_slices(s: &str) -> &str {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_struct`
[INFO] [stderr]  --> src/struct_example.rs:9:8
[INFO] [stderr]   |
[INFO] [stderr] 9 | pub fn example_struct() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `build_user`
[INFO] [stderr]   --> src/struct_example.rs:41:4
[INFO] [stderr]    |
[INFO] [stderr] 41 | fn build_user(email: String, username: String) -> User {
[INFO] [stderr]    |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_tuple_struct`
[INFO] [stderr]   --> src/struct_example.rs:57:4
[INFO] [stderr]    |
[INFO] [stderr] 57 | fn example_tuple_struct() {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_struct_rectangles`
[INFO] [stderr]  --> src/struct_rectangles_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_struct_rectangles() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `calculate_area`
[INFO] [stderr]   --> src/struct_rectangles_example.rs:29:4
[INFO] [stderr]    |
[INFO] [stderr] 29 | fn calculate_area(length: u32, width: u32) -> u32 {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `calculate_area_by_tuple`
[INFO] [stderr]   --> src/struct_rectangles_example.rs:33:4
[INFO] [stderr]    |
[INFO] [stderr] 33 | fn calculate_area_by_tuple(dimensions: (u32, u32)) -> u32 {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `calculate_area_by_struct`
[INFO] [stderr]   --> src/struct_rectangles_example.rs:45:4
[INFO] [stderr]    |
[INFO] [stderr] 45 | fn calculate_area_by_struct(rectangle: &Rectangle) -> u32 {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Rectangle`
[INFO] [stderr]  --> src/method_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | struct Rectangle {
[INFO] [stderr]   |        ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `calculate_area`
[INFO] [stderr]  --> src/method_example.rs:7:8
[INFO] [stderr]   |
[INFO] [stderr] 7 |     fn calculate_area(&self) -> u32 {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `can_hold`
[INFO] [stderr]   --> src/method_example.rs:11:8
[INFO] [stderr]    |
[INFO] [stderr] 11 |     fn can_hold(&self, other: &Rectangle) -> bool {
[INFO] [stderr]    |        ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `square`
[INFO] [stderr]   --> src/method_example.rs:15:8
[INFO] [stderr]    |
[INFO] [stderr] 15 |     fn square(size: u32) -> Rectangle {
[INFO] [stderr]    |        ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_method`
[INFO] [stderr]   --> src/method_example.rs:23:8
[INFO] [stderr]    |
[INFO] [stderr] 23 | pub fn example_method() {
[INFO] [stderr]    |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_enums`
[INFO] [stderr]  --> src/enums_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_enums() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `V4`
[INFO] [stderr]   --> src/enums_example.rs:57:5
[INFO] [stderr]    |
[INFO] [stderr] 57 |     V4,
[INFO] [stderr]    |     ^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `V6`
[INFO] [stderr]   --> src/enums_example.rs:58:5
[INFO] [stderr]    |
[INFO] [stderr] 58 |     V6,
[INFO] [stderr]    |     ^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `V4`
[INFO] [stderr]   --> src/enums_example.rs:69:5
[INFO] [stderr]    |
[INFO] [stderr] 69 |     V4(u8, u8, u8, u8),
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `V6`
[INFO] [stderr]   --> src/enums_example.rs:70:5
[INFO] [stderr]    |
[INFO] [stderr] 70 |     V6(String),
[INFO] [stderr]    |     ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Quit`
[INFO] [stderr]   --> src/enums_example.rs:75:5
[INFO] [stderr]    |
[INFO] [stderr] 75 |     Quit,
[INFO] [stderr]    |     ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Move`
[INFO] [stderr]   --> src/enums_example.rs:76:5
[INFO] [stderr]    |
[INFO] [stderr] 76 |     Move { x: i32, y: i32 },
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Write`
[INFO] [stderr]   --> src/enums_example.rs:77:5
[INFO] [stderr]    |
[INFO] [stderr] 77 |     Write(String),
[INFO] [stderr]    |     ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `ChangeColor`
[INFO] [stderr]   --> src/enums_example.rs:78:5
[INFO] [stderr]    |
[INFO] [stderr] 78 |     ChangeColor(i32, i32, i32),
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `call`
[INFO] [stderr]   --> src/enums_example.rs:82:8
[INFO] [stderr]    |
[INFO] [stderr] 82 |     fn call(&self) {
[INFO] [stderr]    |        ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_match`
[INFO] [stderr]  --> src/match_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_match() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Alabama`
[INFO] [stderr]   --> src/match_example.rs:50:5
[INFO] [stderr]    |
[INFO] [stderr] 50 |     Alabama,
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Alaska`
[INFO] [stderr]   --> src/match_example.rs:51:5
[INFO] [stderr]    |
[INFO] [stderr] 51 |     Alaska,
[INFO] [stderr]    |     ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Washington`
[INFO] [stderr]   --> src/match_example.rs:52:5
[INFO] [stderr]    |
[INFO] [stderr] 52 |     Washington,
[INFO] [stderr]    |     ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Ohio`
[INFO] [stderr]   --> src/match_example.rs:53:5
[INFO] [stderr]    |
[INFO] [stderr] 53 |     Ohio,
[INFO] [stderr]    |     ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: enum is never used: `Coin`
[INFO] [stderr]   --> src/match_example.rs:56:6
[INFO] [stderr]    |
[INFO] [stderr] 56 | enum Coin {
[INFO] [stderr]    |      ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `value_in_cents`
[INFO] [stderr]   --> src/match_example.rs:63:4
[INFO] [stderr]    |
[INFO] [stderr] 63 | fn value_in_cents(coin: Coin) -> u32 {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `plus_one`
[INFO] [stderr]   --> src/match_example.rs:78:4
[INFO] [stderr]    |
[INFO] [stderr] 78 | fn plus_one(x: Option<i32>) -> Option<i32> {
[INFO] [stderr]    |    ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_collection`
[INFO] [stderr]  --> src/collection_example.rs:3:8
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub fn example_collection() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Int`
[INFO] [stderr]    --> src/collection_example.rs:169:5
[INFO] [stderr]     |
[INFO] [stderr] 169 |     Int(i32),
[INFO] [stderr]     |     ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Float`
[INFO] [stderr]    --> src/collection_example.rs:170:5
[INFO] [stderr]     |
[INFO] [stderr] 170 |     Float(f64),
[INFO] [stderr]     |     ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Text`
[INFO] [stderr]    --> src/collection_example.rs:171:5
[INFO] [stderr]     |
[INFO] [stderr] 171 |     Text(String),
[INFO] [stderr]     |     ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_error`
[INFO] [stderr]  --> src/error_example.rs:6:8
[INFO] [stderr]   |
[INFO] [stderr] 6 | pub fn example_error() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `read_username_from_file`
[INFO] [stderr]   --> src/error_example.rs:48:4
[INFO] [stderr]    |
[INFO] [stderr] 48 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `read_username_from_file2`
[INFO] [stderr]   --> src/error_example.rs:63:4
[INFO] [stderr]    |
[INFO] [stderr] 63 | fn read_username_from_file2() -> Result<String, io::Error> {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Guess`
[INFO] [stderr]   --> src/error_example.rs:76:12
[INFO] [stderr]    |
[INFO] [stderr] 76 | pub struct Guess {
[INFO] [stderr]    |            ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `new`
[INFO] [stderr]   --> src/error_example.rs:81:12
[INFO] [stderr]    |
[INFO] [stderr] 81 |     pub fn new(value: u32) -> Guess {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `value`
[INFO] [stderr]   --> src/error_example.rs:89:12
[INFO] [stderr]    |
[INFO] [stderr] 89 |     pub fn value(&self) -> u32 {
[INFO] [stderr]    |            ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `example_generic`
[INFO] [stderr]  --> src/generic_example.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn example_generic() {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `largest`
[INFO] [stderr]   --> src/generic_example.rs:44:4
[INFO] [stderr]    |
[INFO] [stderr] 44 | fn largest(list: &[i32]) -> i32 {
[INFO] [stderr]    |    ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `largest_i32`
[INFO] [stderr]   --> src/generic_example.rs:56:4
[INFO] [stderr]    |
[INFO] [stderr] 56 | fn largest_i32(list: &[i32]) -> i32 {
[INFO] [stderr]    |    ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `largest_char`
[INFO] [stderr]   --> src/generic_example.rs:68:4
[INFO] [stderr]    |
[INFO] [stderr] 68 | fn largest_char(list: &[char]) -> char {
[INFO] [stderr]    |    ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `x`
[INFO] [stderr]   --> src/generic_example.rs:87:8
[INFO] [stderr]    |
[INFO] [stderr] 87 |     fn x(&self) -> &T {
[INFO] [stderr]    |        ^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `mixup`
[INFO] [stderr]   --> src/generic_example.rs:99:8
[INFO] [stderr]    |
[INFO] [stderr] 99 |     fn mixup<V, W>(self, other: Point2<V, W>) -> Point2<T, W> {
[INFO] [stderr]    |        ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 78 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.02s
[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
[INFO] [stdout] 
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/rust_playground-9f7c2c21d97d9c7d
[INFO] running `"docker" "inspect" "16ff00de20d8c06b16bfb06a11df5924d18169ae7d624ad402c4d3e94e8ff784"`
[INFO] running `"docker" "rm" "-f" "16ff00de20d8c06b16bfb06a11df5924d18169ae7d624ad402c4d3e94e8ff784"`
[INFO] [stdout] 16ff00de20d8c06b16bfb06a11df5924d18169ae7d624ad402c4d3e94e8ff784