[INFO] updating cached repository https://github.com/jheloper/rust-playground
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] [stderr] From https://github.com/jheloper/rust-playground
[INFO] [stderr]    0cb9bc8..0fa6373  master     -> master
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 0fa63735f6992212e89c8a82b545a41d92d75d39
[INFO] checking jheloper/rust-playground against try#1a608893c03d7722effeb0058e82770bd36b4b3c for pr-66504-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjheloper%2Frust-playground" "/workspace/builds/worker-8/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jheloper/rust-playground on toolchain 1a608893c03d7722effeb0058e82770bd36b4b3c
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1a608893c03d7722effeb0058e82770bd36b4b3c" "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-8/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" "+1a608893c03d7722effeb0058e82770bd36b4b3c" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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=forbid" "-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" "+1a608893c03d7722effeb0058e82770bd36b4b3c" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] d3d8ff25ddef13e0347cdc2745f56f68f71072f6feb27f085c1f87f112f62625
[INFO] running `"docker" "start" "-a" "d3d8ff25ddef13e0347cdc2745f56f68f71072f6feb27f085c1f87f112f62625"`
[INFO] [stderr]     Checking 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: consider prefixing 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: consider prefixing 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: consider prefixing with an underscore: `_some_string`
[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: 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: method is never used: `calculate_area`
[INFO] [stderr]  --> src/method_example.rs:7:5
[INFO] [stderr]   |
[INFO] [stderr] 7 |     fn calculate_area(&self) -> u32 {
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `can_hold`
[INFO] [stderr]   --> src/method_example.rs:11:5
[INFO] [stderr]    |
[INFO] [stderr] 11 |     fn can_hold(&self, other: &Rectangle) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `square`
[INFO] [stderr]   --> src/method_example.rs:15:5
[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: unused variable: `x`
[INFO] [stderr]   --> src/function_example.rs:17:9
[INFO] [stderr]    |
[INFO] [stderr] 17 |     let x = 10;
[INFO] [stderr]    |         ^ help: consider prefixing 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: consider prefixing 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: consider prefixing with an underscore: `_some_string`
[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: 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: method is never used: `calculate_area`
[INFO] [stderr]  --> src/method_example.rs:7:5
[INFO] [stderr]   |
[INFO] [stderr] 7 |     fn calculate_area(&self) -> u32 {
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `can_hold`
[INFO] [stderr]   --> src/method_example.rs:11:5
[INFO] [stderr]    |
[INFO] [stderr] 11 |     fn can_hold(&self, other: &Rectangle) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `square`
[INFO] [stderr]   --> src/method_example.rs:15:5
[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]     Finished dev [unoptimized + debuginfo] target(s) in 1.41s
[INFO] running `"docker" "inspect" "d3d8ff25ddef13e0347cdc2745f56f68f71072f6feb27f085c1f87f112f62625"`
[INFO] running `"docker" "rm" "-f" "d3d8ff25ddef13e0347cdc2745f56f68f71072f6feb27f085c1f87f112f62625"`
[INFO] [stdout] d3d8ff25ddef13e0347cdc2745f56f68f71072f6feb27f085c1f87f112f62625