[INFO] updating cached repository https://github.com/clD11/rust-katas
[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] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 2c92c5c8c675ac2054d3a84dc7ce4d67085fe3c0
[INFO] checking clD11/rust-katas against master#45d050cde277b22a755847338f2acc2c7b834141 for pr-71393
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FclD11%2Frust-katas" "/workspace/builds/worker-6/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/clD11/rust-katas on toolchain 45d050cde277b22a755847338f2acc2c7b834141
[INFO] running `"/workspace/cargo-home/bin/cargo" "+45d050cde277b22a755847338f2acc2c7b834141" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/clD11/rust-katas
[INFO] finished tweaking git repo https://github.com/clD11/rust-katas
[INFO] tweaked toml for git repo https://github.com/clD11/rust-katas written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/clD11/rust-katas already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+45d050cde277b22a755847338f2acc2c7b834141" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "+45d050cde277b22a755847338f2acc2c7b834141" "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] ec3d84eb6c2c2a19c5620b4e73a3f56a93ea38b945a9c47085d8f1432feeea60
[INFO] running `"docker" "start" "-a" "ec3d84eb6c2c2a19c5620b4e73a3f56a93ea38b945a9c47085d8f1432feeea60"`
[INFO] [stderr]     Checking getrandom v0.1.14
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking rust-katas v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused import: `std::string::String`
[INFO] [stderr]  --> src/rust_book/slice.rs:6:5
[INFO] [stderr]   |
[INFO] [stderr] 6 | use std::string::String;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `cat_and_mouse`
[INFO] [stderr]  --> src/hackerrank/problem_solving/cat_mouse.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn cat_and_mouse(x: i32, y: i32, z: i32) -> &'static str {
[INFO] [stderr]   |        ^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `divisible_sum_pairs`
[INFO] [stderr]  --> src/hackerrank/problem_solving/divisible_sum_pairs.rs:1:9
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn  divisible_sum_pairs(n: usize, k: u32, ar: &[u32]) -> u32 {
[INFO] [stderr]   |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `sum`
[INFO] [stderr]  --> src/hackerrank/problem_solving/distinct_pairs.rs:4:8
[INFO] [stderr]   |
[INFO] [stderr] 4 | pub fn sum(nums: &[u32], target: u32) -> u32 {
[INFO] [stderr]   |        ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `to_roman_numeral`
[INFO] [stderr]   --> src/hackerrank/problem_solving/number_converter.rs:26:8
[INFO] [stderr]    |
[INFO] [stderr] 26 | pub fn to_roman_numeral(number: u32) -> String {
[INFO] [stderr]    |        ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: enum is never used: `IpAddrKind`
[INFO] [stderr]  --> src/rust_book/defining_enums.rs:1:6
[INFO] [stderr]   |
[INFO] [stderr] 1 | enum IpAddrKind {
[INFO] [stderr]   |      ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `guess`
[INFO] [stderr]  --> src/rust_book/guessing_game.rs:5:8
[INFO] [stderr]   |
[INFO] [stderr] 5 | pub fn guess() {
[INFO] [stderr]   |        ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `square`
[INFO] [stderr]   --> src/rust_book/rectangle.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 |     fn square(d: i32) -> Rectangle {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `area`
[INFO] [stderr]   --> src/rust_book/rectangle.rs:20:5
[INFO] [stderr]    |
[INFO] [stderr] 20 |     fn area(&self) -> i32 {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `can_hold`
[INFO] [stderr]   --> src/rust_book/rectangle.rs:24:5
[INFO] [stderr]    |
[INFO] [stderr] 24 |     fn can_hold(&self, rectangle: &Rectangle) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `find_first_word`
[INFO] [stderr]  --> src/rust_book/slice.rs:8:8
[INFO] [stderr]   |
[INFO] [stderr] 8 | pub fn find_first_word(s: &str) -> &str {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 11 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: irrefutable if-let pattern
[INFO] [stderr]   --> src/rust_book/defining_enums.rs:9:5
[INFO] [stderr]    |
[INFO] [stderr] 9  | /     if let IpAddrKind::V4(actual) = V4 {
[INFO] [stderr] 10 | |         assert_eq!(actual, expected);
[INFO] [stderr] 11 | |     }
[INFO] [stderr]    | |_____^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `guess`
[INFO] [stderr]  --> src/rust_book/guessing_game.rs:5:8
[INFO] [stderr]   |
[INFO] [stderr] 5 | pub fn guess() {
[INFO] [stderr]   |        ^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function `test_V4` should have a snake case name
[INFO] [stderr]  --> src/rust_book/defining_enums.rs:6:4
[INFO] [stderr]   |
[INFO] [stderr] 6 | fn test_V4() {
[INFO] [stderr]   |    ^^^^^^^ help: convert the identifier to snake case (notice the capitalization): `test_v4`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(non_snake_case)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable `V4` should have a snake case name
[INFO] [stderr]  --> src/rust_book/defining_enums.rs:8:9
[INFO] [stderr]   |
[INFO] [stderr] 8 |     let V4 = IpAddrKind::V4(String::from("127.0.0.1"));
[INFO] [stderr]   |         ^^ help: convert the identifier to snake case (notice the capitalization): `v4`
[INFO] [stderr] 
[INFO] [stderr] warning: 4 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.32s
[INFO] running `"docker" "inspect" "ec3d84eb6c2c2a19c5620b4e73a3f56a93ea38b945a9c47085d8f1432feeea60"`
[INFO] running `"docker" "rm" "-f" "ec3d84eb6c2c2a19c5620b4e73a3f56a93ea38b945a9c47085d8f1432feeea60"`
[INFO] [stdout] ec3d84eb6c2c2a19c5620b4e73a3f56a93ea38b945a9c47085d8f1432feeea60