[INFO] cloning repository https://github.com/acseed/rust_practice
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/acseed/rust_practice" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Facseed%2Frust_practice", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Facseed%2Frust_practice'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3bd4f3a46fb6ed293440bb0ed57f563938e61a7e
[INFO] checking acseed/rust_practice/3bd4f3a46fb6ed293440bb0ed57f563938e61a7e against master#ab869e094a907cc5d19b4080f22eccaf347f1f95 for pr-129604
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Facseed%2Frust_practice" "/workspace/builds/worker-3-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/acseed/rust_practice on toolchain ab869e094a907cc5d19b4080f22eccaf347f1f95
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/acseed/rust_practice
[INFO] finished tweaking git repo https://github.com/acseed/rust_practice
[INFO] tweaked toml for git repo https://github.com/acseed/rust_practice written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/acseed/rust_practice already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4a2eba97e0ab1d885f6d5227232a6f1117595e691f9d7a9546fa0d1ecd96950d
[INFO] running `Command { std: "docker" "start" "-a" "4a2eba97e0ab1d885f6d5227232a6f1117595e691f9d7a9546fa0d1ecd96950d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4a2eba97e0ab1d885f6d5227232a6f1117595e691f9d7a9546fa0d1ecd96950d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4a2eba97e0ab1d885f6d5227232a6f1117595e691f9d7a9546fa0d1ecd96950d", kill_on_drop: false }`
[INFO] [stdout] 4a2eba97e0ab1d885f6d5227232a6f1117595e691f9d7a9546fa0d1ecd96950d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f7ab0dd7c770601ea74fab75ec16a19d7e27a3281e57f1a4d8c0db4c625cadf8
[INFO] running `Command { std: "docker" "start" "-a" "f7ab0dd7c770601ea74fab75ec16a19d7e27a3281e57f1a4d8c0db4c625cadf8", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_practice v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: methods `size`, `get`, `maximum`, and `minimum` are never used
[INFO] [stdout]    --> src/ds/rbtree.rs:132:12
[INFO] [stdout]     |
[INFO] [stdout] 114 | impl<K, V> RBTree<K, V> where K: Ord + Clone + Display + ToString, V: Clone + Display + ToString {
[INFO] [stdout]     | ------------------------------------------------------------------------------------------------ methods in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 132 |     pub fn size(&self) -> usize {
[INFO] [stdout]     |            ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 138 |     pub fn get(&self, key: &K) -> Option<&V> {
[INFO] [stdout]     |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 151 |     pub fn maximum(&self) -> Option<(&K,&V)> {
[INFO] [stdout]     |            ^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 156 |     pub fn minimum(&self) -> Option<(&K,&V)> {
[INFO] [stdout]     |            ^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.33s
[INFO] running `Command { std: "docker" "inspect" "f7ab0dd7c770601ea74fab75ec16a19d7e27a3281e57f1a4d8c0db4c625cadf8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f7ab0dd7c770601ea74fab75ec16a19d7e27a3281e57f1a4d8c0db4c625cadf8", kill_on_drop: false }`
[INFO] [stdout] f7ab0dd7c770601ea74fab75ec16a19d7e27a3281e57f1a4d8c0db4c625cadf8