[INFO] cloning repository https://github.com/sh0623k/coding_interview
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/sh0623k/coding_interview" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsh0623k%2Fcoding_interview", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsh0623k%2Fcoding_interview'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 2ef72629016f5b7515d77ab2a94ef7f8fe2e55c8
[INFO] testing sh0623k/coding_interview against beta-2021-08-01 for beta-1.55-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsh0623k%2Fcoding_interview" "/workspace/builds/worker-46/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-46/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/sh0623k/coding_interview on toolchain beta-2021-08-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/sh0623k/coding_interview
[INFO] finished tweaking git repo https://github.com/sh0623k/coding_interview
[INFO] tweaked toml for git repo https://github.com/sh0623k/coding_interview written to /workspace/builds/worker-46/source/Cargo.toml
[INFO] crate git repo https://github.com/sh0623k/coding_interview already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-46/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-46/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] db0e943dbb53693f4686fd56b9d02aa92ee43284cfcec245af05b0b78fd52e54
[INFO] running `Command { std: "docker" "start" "-a" "db0e943dbb53693f4686fd56b9d02aa92ee43284cfcec245af05b0b78fd52e54", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "db0e943dbb53693f4686fd56b9d02aa92ee43284cfcec245af05b0b78fd52e54", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "db0e943dbb53693f4686fd56b9d02aa92ee43284cfcec245af05b0b78fd52e54", kill_on_drop: false }`
[INFO] [stdout] db0e943dbb53693f4686fd56b9d02aa92ee43284cfcec245af05b0b78fd52e54
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-46/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-46/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b78719a78bac48df88612258c7d98d6ff0d1f733fb018a9360aceef07c546c0b
[INFO] running `Command { std: "docker" "start" "-a" "b78719a78bac48df88612258c7d98d6ff0d1f733fb018a9360aceef07c546c0b", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling coding_interview v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/linked_list.rs:147:17
[INFO] [stdout]     |
[INFO] [stdout] 147 |                 &node.borrow_mut().remove();
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/bin/ch02p03.rs:13:13
[INFO] [stdout]    |
[INFO] [stdout] 13 |             &node.borrow_mut().remove();
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/bin/ch04p02.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let mut mbst = MinimalBinarySearchTree::<i32>::new(&arr);
[INFO] [stdout]   |         ----^^^^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `card`
[INFO] [stdout]    --> src/bin/ch07p01.rs:108:28
[INFO] [stdout]     |
[INFO] [stdout] 108 |     fn add_card(&mut self, card: BlackJackCard) {
[INFO] [stdout]     |                            ^^^^ help: if this is intentional, prefix it with an underscore: `_card`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/ch07p01.rs:87:13
[INFO] [stdout]    |
[INFO] [stdout] 87 |         let mut value = 0;
[INFO] [stdout]    |             ----^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/bin/ch07p01.rs:104:13
[INFO] [stdout]     |
[INFO] [stdout] 104 |         let mut score = 0;
[INFO] [stdout]     |             ----^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/bin/ch07p01.rs:132:13
[INFO] [stdout]     |
[INFO] [stdout] 132 |         let mut hand: Vec<BlackJackCard> = vec![];
[INFO] [stdout]     |             ----^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 16.15s
[INFO] running `Command { std: "docker" "inspect" "b78719a78bac48df88612258c7d98d6ff0d1f733fb018a9360aceef07c546c0b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b78719a78bac48df88612258c7d98d6ff0d1f733fb018a9360aceef07c546c0b", kill_on_drop: false }`
[INFO] [stdout] b78719a78bac48df88612258c7d98d6ff0d1f733fb018a9360aceef07c546c0b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-46/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-46/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4f808fc2c2ba44da767a603ec1b01508cc131787e1f3231b55ca38dc529a5d86
[INFO] running `Command { std: "docker" "start" "-a" "4f808fc2c2ba44da767a603ec1b01508cc131787e1f3231b55ca38dc529a5d86", kill_on_drop: false }`
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/linked_list.rs:147:17
[INFO] [stdout]     |
[INFO] [stdout] 147 |                 &node.borrow_mut().remove();
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling coding_interview v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/bin/ch04p02.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let mut mbst = MinimalBinarySearchTree::<i32>::new(&arr);
[INFO] [stdout]   |         ----^^^^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `card`
[INFO] [stdout]    --> src/bin/ch07p01.rs:108:28
[INFO] [stdout]     |
[INFO] [stdout] 108 |     fn add_card(&mut self, card: BlackJackCard) {
[INFO] [stdout]     |                            ^^^^ help: if this is intentional, prefix it with an underscore: `_card`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/ch07p01.rs:87:13
[INFO] [stdout]    |
[INFO] [stdout] 87 |         let mut value = 0;
[INFO] [stdout]    |             ----^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/bin/ch07p01.rs:104:13
[INFO] [stdout]     |
[INFO] [stdout] 104 |         let mut score = 0;
[INFO] [stdout]     |             ----^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/bin/ch07p01.rs:132:13
[INFO] [stdout]     |
[INFO] [stdout] 132 |         let mut hand: Vec<BlackJackCard> = vec![];
[INFO] [stdout]     |             ----^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/linked_list.rs:147:17
[INFO] [stdout]     |
[INFO] [stdout] 147 |                 &node.borrow_mut().remove();
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/linked_list.rs:405:17
[INFO] [stdout]     |
[INFO] [stdout] 405 |                 &node.borrow_mut().remove();
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/bin/ch02p03.rs:13:13
[INFO] [stdout]    |
[INFO] [stdout] 13 |             &node.borrow_mut().remove();
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `coding_interview`; 2 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustc --crate-name coding_interview --edition=2018 src/lib.rs --error-format=json --json=diagnostic-rendered-ansi --emit=dep-info,link -C embed-bitcode=no -C debuginfo=2 --test -C metadata=dc5a3c17d3789af0 -C extra-filename=-dc5a3c17d3789af0 --out-dir /opt/rustwide/target/debug/deps -L dependency=/opt/rustwide/target/debug/deps --cap-lints=warn` (signal: 9, SIGKILL: kill)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "4f808fc2c2ba44da767a603ec1b01508cc131787e1f3231b55ca38dc529a5d86", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4f808fc2c2ba44da767a603ec1b01508cc131787e1f3231b55ca38dc529a5d86", kill_on_drop: false }`
[INFO] [stdout] 4f808fc2c2ba44da767a603ec1b01508cc131787e1f3231b55ca38dc529a5d86
