[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] [stderr] /workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs: No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 1)
[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] [stderr] /workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs/objects/info: No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 2)
[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] [stderr] error: copy-fd: write returned: No space left on device
[INFO] [stderr] fatal: cannot copy '/usr/share/git-core/templates/hooks/prepare-commit-msg.sample' to '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs/hooks/prepare-commit-msg.sample': No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 3)
[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] [stderr] error: copy-fd: write returned: No space left on device
[INFO] [stderr] fatal: cannot copy '/usr/share/git-core/templates/hooks/pre-rebase.sample' to '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs/hooks/pre-rebase.sample': No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 4)
[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] [stderr] /workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs: No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 5)
[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] [stderr] /workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs: No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 6)
[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] [stderr] /workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs: No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 7)
[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] [stderr] /workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs: No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 8)
[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] [stderr] /workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs: No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 9)
[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] [stderr] /workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs: No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 10)
[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] [stderr] /workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs: No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 11)
[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] [stderr] /workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs: No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 12)
[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] [stderr] /workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs: No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 13)
[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] [stderr] /workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs: No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 14)
[INFO] cloning repository https://github.com/perryqh/ph-data-structures-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/perryqh/ph-data-structures-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] bc28ab47baebb2db369abd526079b8847153ab8a
[INFO] checking perryqh/ph-data-structures-rs against try#1bd50d4315eb15970d395b6be5823f9384707693 for pr-140151
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fperryqh%2Fph-data-structures-rs" "/workspace/builds/worker-3-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/perryqh/ph-data-structures-rs on toolchain 1bd50d4315eb15970d395b6be5823f9384707693
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1bd50d4315eb15970d395b6be5823f9384707693" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/perryqh/ph-data-structures-rs
[INFO] finished tweaking git repo https://github.com/perryqh/ph-data-structures-rs
[INFO] tweaked toml for git repo https://github.com/perryqh/ph-data-structures-rs written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/perryqh/ph-data-structures-rs 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" "+1bd50d4315eb15970d395b6be5823f9384707693" "fetch" "--manifest-path" "Cargo.toml", 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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:b0b074c097205a61b89e8ad263052f976b2b332c4dc5f02aef1fe52501660d6e" "/opt/rustwide/cargo-home/bin/cargo" "+1bd50d4315eb15970d395b6be5823f9384707693" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d5906a7227ba4956b3a3bfcb076c1da666b54113469f1c32403a8bbc4176472f
[INFO] running `Command { std: "docker" "start" "-a" "d5906a7227ba4956b3a3bfcb076c1da666b54113469f1c32403a8bbc4176472f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d5906a7227ba4956b3a3bfcb076c1da666b54113469f1c32403a8bbc4176472f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d5906a7227ba4956b3a3bfcb076c1da666b54113469f1c32403a8bbc4176472f", kill_on_drop: false }`
[INFO] [stdout] d5906a7227ba4956b3a3bfcb076c1da666b54113469f1c32403a8bbc4176472f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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:b0b074c097205a61b89e8ad263052f976b2b332c4dc5f02aef1fe52501660d6e" "/opt/rustwide/cargo-home/bin/cargo" "+1bd50d4315eb15970d395b6be5823f9384707693" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a6891b567f1aa4cd2c8050a0e74ef40a06fe429992dc99f00fabdf4893374915
[INFO] running `Command { std: "docker" "start" "-a" "a6891b567f1aa4cd2c8050a0e74ef40a06fe429992dc99f00fabdf4893374915", kill_on_drop: false }`
[INFO] [stderr]     Checking ph-data-structures v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/linked_list.rs:35:13
[INFO] [stdout]    |
[INFO] [stdout] 35 |         let mut node = self.head.take(); // self.head is now none
[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: `head`
[INFO] [stdout]   --> src/lru_cache.rs:57:25
[INFO] [stdout]    |
[INFO] [stdout] 57 |                     let head = self.list.pop_front();
[INFO] [stdout]    |                         ^^^^ help: if this is intentional, prefix it with an underscore: `_head`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Tree` is never constructed
[INFO] [stdout]  --> src/binary_tree.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct Tree {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `value`, `left`, and `right` are never read
[INFO] [stdout]   --> src/binary_tree.rs:9:5
[INFO] [stdout]    |
[INFO] [stdout] 8  | struct Node {
[INFO] [stdout]    |        ---- fields in this struct
[INFO] [stdout] 9  |     value: i32,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 10 |     left: Option<Box<Node>>,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 11 |     right: Option<Box<Node>>,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Node` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/binary_tree.rs:15:8
[INFO] [stdout]    |
[INFO] [stdout] 14 | impl Node {
[INFO] [stdout]    | --------- associated function in this implementation
[INFO] [stdout] 15 |     fn new(value: i32) -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `insert`, `insert_iterative`, and `insert_recursive` are never used
[INFO] [stdout]   --> src/binary_tree.rs:31:8
[INFO] [stdout]    |
[INFO] [stdout] 30 | impl Tree {
[INFO] [stdout]    | --------- associated items in this implementation
[INFO] [stdout] 31 |     fn new() -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] ...
[INFO] [stdout] 35 |     fn insert(&mut self, value: i32) {
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 48 |     fn insert_iterative(&mut self, value: i32) {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 83 |     fn insert_recursive(node: &mut Box<Node>, value: i32) {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `LinkedList` is never constructed
[INFO] [stdout]  --> src/linked_list.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct LinkedList<T> {
[INFO] [stdout]   |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `value` and `next` are never read
[INFO] [stdout]  --> src/linked_list.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | struct Node<T> {
[INFO] [stdout]   |        ---- fields in this struct
[INFO] [stdout] 6 |     value: T,
[INFO] [stdout]   |     ^^^^^
[INFO] [stdout] 7 |     next: Option<Box<Node<T>>>,
[INFO] [stdout]   |     ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/linked_list.rs:18:12
[INFO] [stdout]    |
[INFO] [stdout] 17 | impl<T: Copy> Node<T> {
[INFO] [stdout]    | --------------------- associated function in this implementation
[INFO] [stdout] 18 |     pub fn new(value: T) -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `push_front`, and `pop_front` are never used
[INFO] [stdout]   --> src/linked_list.rs:24:12
[INFO] [stdout]    |
[INFO] [stdout] 23 | impl<T: Copy> LinkedList<T> {
[INFO] [stdout]    | --------------------------- associated items in this implementation
[INFO] [stdout] 24 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 28 |     pub fn push_front(&mut self, value: T) {
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 34 |     pub fn pop_front(&mut self) -> Option<T> {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/linked_list.rs:35:13
[INFO] [stdout]    |
[INFO] [stdout] 35 |         let mut node = self.head.take(); // self.head is now none
[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: `head`
[INFO] [stdout]   --> src/lru_cache.rs:57:25
[INFO] [stdout]    |
[INFO] [stdout] 57 |                     let head = self.list.pop_front();
[INFO] [stdout]    |                         ^^^^ help: if this is intentional, prefix it with an underscore: `_head`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `insert_iterative` is never used
[INFO] [stdout]   --> src/binary_tree.rs:48:8
[INFO] [stdout]    |
[INFO] [stdout] 30 | impl Tree {
[INFO] [stdout]    | --------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 48 |     fn insert_iterative(&mut self, value: i32) {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.20s
[INFO] running `Command { std: "docker" "inspect" "a6891b567f1aa4cd2c8050a0e74ef40a06fe429992dc99f00fabdf4893374915", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a6891b567f1aa4cd2c8050a0e74ef40a06fe429992dc99f00fabdf4893374915", kill_on_drop: false }`
[INFO] [stdout] a6891b567f1aa4cd2c8050a0e74ef40a06fe429992dc99f00fabdf4893374915
