[INFO] cloning repository https://github.com/CCBTony/rust_datastruct
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/CCBTony/rust_datastruct" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCCBTony%2Frust_datastruct"`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCCBTony%2Frust_datastruct'...
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 25b0fc476ee391f5c4a90961f1ea540285622ffe
[INFO] testing CCBTony/rust_datastruct against 1.44.0 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCCBTony%2Frust_datastruct" "/workspace/builds/worker-3/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/CCBTony/rust_datastruct on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/CCBTony/rust_datastruct
[INFO] finished tweaking git repo https://github.com/CCBTony/rust_datastruct
[INFO] tweaked toml for git repo https://github.com/CCBTony/rust_datastruct written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/CCBTony/rust_datastruct already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr] error: the lock file /workspace/builds/worker-3/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] [stderr] If you want to try to generate the lock file without accessing the network, use the --offline flag.
[INFO] the lockfile is outdated, regenerating it
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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=warn" "-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" "+1.44.0" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 5e8ad54ed58afe8309393061e0ee38815f369ef163ea072f8531e0d340d5d1db
[INFO] running `"docker" "start" "-a" "5e8ad54ed58afe8309393061e0ee38815f369ef163ea072f8531e0d340d5d1db"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling getset v0.0.7
[INFO] [stderr]    Compiling rust_study v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused import: `tree::*`
[INFO] [stderr]  --> src/main.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use tree::*;
[INFO] [stderr]   |     ^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `cur_p`
[INFO] [stderr]    --> src/tree.rs:434:21
[INFO] [stderr]     |
[INFO] [stderr] 434 |                 let cur_p = cur.as_ptr();
[INFO] [stderr]     |                     ^^^^^ help: if this is intentional, prefix it with an underscore: `_cur_p`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:555:25
[INFO] [stderr]     |
[INFO] [stderr] 555 |                     let mut k1 = Rc::clone(&root);
[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: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:556:25
[INFO] [stderr]     |
[INFO] [stderr] 556 |                     let mut k2 = link_right(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:557:25
[INFO] [stderr]     |
[INFO] [stderr] 557 |                     let mut y = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:567:25
[INFO] [stderr]     |
[INFO] [stderr] 567 |                     let mut k1 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:568:25
[INFO] [stderr]     |
[INFO] [stderr] 568 |                     let mut k3 = link_left(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:569:25
[INFO] [stderr]     |
[INFO] [stderr] 569 |                     let mut k2 = link_right(Rc::clone(&k3), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:570:25
[INFO] [stderr]     |
[INFO] [stderr] 570 |                     let mut b = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:571:25
[INFO] [stderr]     |
[INFO] [stderr] 571 |                     let mut c = link_right(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:583:25
[INFO] [stderr]     |
[INFO] [stderr] 583 |                     let mut k2 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:584:25
[INFO] [stderr]     |
[INFO] [stderr] 584 |                     let mut k1 = link_left(Rc::clone(&k2), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:585:25
[INFO] [stderr]     |
[INFO] [stderr] 585 |                     let mut y = link_left(Rc::clone(&k1), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:595:25
[INFO] [stderr]     |
[INFO] [stderr] 595 |                     let mut k3 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:596:25
[INFO] [stderr]     |
[INFO] [stderr] 596 |                     let mut k1 = link_left(Rc::clone(&k3), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:597:25
[INFO] [stderr]     |
[INFO] [stderr] 597 |                     let mut k2 = link_right(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:598:25
[INFO] [stderr]     |
[INFO] [stderr] 598 |                     let mut b = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:599:25
[INFO] [stderr]     |
[INFO] [stderr] 599 |                     let mut c = link_right(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/tree.rs:46:9
[INFO] [stderr]    |
[INFO] [stderr] 46 |         pub fn new(key: String, value: V) -> Self {
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `depth`
[INFO] [stderr]   --> src/tree.rs:56:9
[INFO] [stderr]    |
[INFO] [stderr] 56 |         pub fn depth(&self) -> i32 {
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `dumps`
[INFO] [stderr]    --> src/tree.rs:316:12
[INFO] [stderr]     |
[INFO] [stderr] 316 |     pub fn dumps<V: Clone + Display>(node: Rc<RefCell<BinaryNode<V>>>, level: i32) {
[INFO] [stderr]     |            ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]    --> src/tree.rs:473:9
[INFO] [stderr]     |
[INFO] [stderr] 473 |         pub fn new() -> Self { Self { root: None } }
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `min_val`
[INFO] [stderr]    --> src/tree.rs:475:9
[INFO] [stderr]     |
[INFO] [stderr] 475 |         pub fn min_val(&self) -> Option<Rc<RefCell<V>>> {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `min_val_clone`
[INFO] [stderr]    --> src/tree.rs:493:9
[INFO] [stderr]     |
[INFO] [stderr] 493 |         pub fn min_val_clone(&self) -> Option<V> {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `max_val`
[INFO] [stderr]    --> src/tree.rs:500:9
[INFO] [stderr]     |
[INFO] [stderr] 500 |         pub fn max_val(&self) -> Option<Rc<RefCell<V>>> {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `max_val_clone`
[INFO] [stderr]    --> src/tree.rs:518:9
[INFO] [stderr]     |
[INFO] [stderr] 518 |         pub fn max_val_clone(&self) -> Option<V> {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `height`
[INFO] [stderr]    --> src/tree.rs:525:9
[INFO] [stderr]     |
[INFO] [stderr] 525 |         pub fn height(&self) -> i32 {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 27 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 13.41s
[INFO] running `"docker" "inspect" "5e8ad54ed58afe8309393061e0ee38815f369ef163ea072f8531e0d340d5d1db"`
[INFO] running `"docker" "rm" "-f" "5e8ad54ed58afe8309393061e0ee38815f369ef163ea072f8531e0d340d5d1db"`
[INFO] [stdout] 5e8ad54ed58afe8309393061e0ee38815f369ef163ea072f8531e0d340d5d1db
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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=warn" "-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" "+1.44.0" "test" "--frozen" "--no-run"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 1ec586979f431c8bcb544b017ed4fef53e42be0b748e66da2fe62c4eb88a07f9
[INFO] running `"docker" "start" "-a" "1ec586979f431c8bcb544b017ed4fef53e42be0b748e66da2fe62c4eb88a07f9"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling rust_study v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused import: `tree::*`
[INFO] [stderr]  --> src/main.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use tree::*;
[INFO] [stderr]   |     ^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `cur_p`
[INFO] [stderr]    --> src/tree.rs:434:21
[INFO] [stderr]     |
[INFO] [stderr] 434 |                 let cur_p = cur.as_ptr();
[INFO] [stderr]     |                     ^^^^^ help: if this is intentional, prefix it with an underscore: `_cur_p`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:555:25
[INFO] [stderr]     |
[INFO] [stderr] 555 |                     let mut k1 = Rc::clone(&root);
[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: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:556:25
[INFO] [stderr]     |
[INFO] [stderr] 556 |                     let mut k2 = link_right(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:557:25
[INFO] [stderr]     |
[INFO] [stderr] 557 |                     let mut y = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:567:25
[INFO] [stderr]     |
[INFO] [stderr] 567 |                     let mut k1 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:568:25
[INFO] [stderr]     |
[INFO] [stderr] 568 |                     let mut k3 = link_left(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:569:25
[INFO] [stderr]     |
[INFO] [stderr] 569 |                     let mut k2 = link_right(Rc::clone(&k3), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:570:25
[INFO] [stderr]     |
[INFO] [stderr] 570 |                     let mut b = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:571:25
[INFO] [stderr]     |
[INFO] [stderr] 571 |                     let mut c = link_right(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:583:25
[INFO] [stderr]     |
[INFO] [stderr] 583 |                     let mut k2 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:584:25
[INFO] [stderr]     |
[INFO] [stderr] 584 |                     let mut k1 = link_left(Rc::clone(&k2), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:585:25
[INFO] [stderr]     |
[INFO] [stderr] 585 |                     let mut y = link_left(Rc::clone(&k1), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:595:25
[INFO] [stderr]     |
[INFO] [stderr] 595 |                     let mut k3 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:596:25
[INFO] [stderr]     |
[INFO] [stderr] 596 |                     let mut k1 = link_left(Rc::clone(&k3), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:597:25
[INFO] [stderr]     |
[INFO] [stderr] 597 |                     let mut k2 = link_right(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:598:25
[INFO] [stderr]     |
[INFO] [stderr] 598 |                     let mut b = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:599:25
[INFO] [stderr]     |
[INFO] [stderr] 599 |                     let mut c = link_right(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/tree.rs:46:9
[INFO] [stderr]    |
[INFO] [stderr] 46 |         pub fn new(key: String, value: V) -> Self {
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `depth`
[INFO] [stderr]   --> src/tree.rs:56:9
[INFO] [stderr]    |
[INFO] [stderr] 56 |         pub fn depth(&self) -> i32 {
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `dumps`
[INFO] [stderr]    --> src/tree.rs:316:12
[INFO] [stderr]     |
[INFO] [stderr] 316 |     pub fn dumps<V: Clone + Display>(node: Rc<RefCell<BinaryNode<V>>>, level: i32) {
[INFO] [stderr]     |            ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]    --> src/tree.rs:473:9
[INFO] [stderr]     |
[INFO] [stderr] 473 |         pub fn new() -> Self { Self { root: None } }
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `min_val`
[INFO] [stderr]    --> src/tree.rs:475:9
[INFO] [stderr]     |
[INFO] [stderr] 475 |         pub fn min_val(&self) -> Option<Rc<RefCell<V>>> {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `min_val_clone`
[INFO] [stderr]    --> src/tree.rs:493:9
[INFO] [stderr]     |
[INFO] [stderr] 493 |         pub fn min_val_clone(&self) -> Option<V> {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `max_val`
[INFO] [stderr]    --> src/tree.rs:500:9
[INFO] [stderr]     |
[INFO] [stderr] 500 |         pub fn max_val(&self) -> Option<Rc<RefCell<V>>> {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `max_val_clone`
[INFO] [stderr]    --> src/tree.rs:518:9
[INFO] [stderr]     |
[INFO] [stderr] 518 |         pub fn max_val_clone(&self) -> Option<V> {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `height`
[INFO] [stderr]    --> src/tree.rs:525:9
[INFO] [stderr]     |
[INFO] [stderr] 525 |         pub fn height(&self) -> i32 {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 27 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::search::*`
[INFO] [stderr]    --> src/tree.rs:655:13
[INFO] [stderr]     |
[INFO] [stderr] 655 |         use super::search::*;
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `tree::*`
[INFO] [stderr]  --> src/main.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use tree::*;
[INFO] [stderr]   |     ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::search`
[INFO] [stderr]    --> src/tree.rs:623:13
[INFO] [stderr]     |
[INFO] [stderr] 623 |         use super::search::*;
[INFO] [stderr]     |             ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `cur_p`
[INFO] [stderr]    --> src/tree.rs:434:21
[INFO] [stderr]     |
[INFO] [stderr] 434 |                 let cur_p = cur.as_ptr();
[INFO] [stderr]     |                     ^^^^^ help: if this is intentional, prefix it with an underscore: `_cur_p`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:555:25
[INFO] [stderr]     |
[INFO] [stderr] 555 |                     let mut k1 = Rc::clone(&root);
[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: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:556:25
[INFO] [stderr]     |
[INFO] [stderr] 556 |                     let mut k2 = link_right(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:557:25
[INFO] [stderr]     |
[INFO] [stderr] 557 |                     let mut y = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:567:25
[INFO] [stderr]     |
[INFO] [stderr] 567 |                     let mut k1 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:568:25
[INFO] [stderr]     |
[INFO] [stderr] 568 |                     let mut k3 = link_left(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:569:25
[INFO] [stderr]     |
[INFO] [stderr] 569 |                     let mut k2 = link_right(Rc::clone(&k3), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:570:25
[INFO] [stderr]     |
[INFO] [stderr] 570 |                     let mut b = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:571:25
[INFO] [stderr]     |
[INFO] [stderr] 571 |                     let mut c = link_right(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:583:25
[INFO] [stderr]     |
[INFO] [stderr] 583 |                     let mut k2 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:584:25
[INFO] [stderr]     |
[INFO] [stderr] 584 |                     let mut k1 = link_left(Rc::clone(&k2), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:585:25
[INFO] [stderr]     |
[INFO] [stderr] 585 |                     let mut y = link_left(Rc::clone(&k1), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:595:25
[INFO] [stderr]     |
[INFO] [stderr] 595 |                     let mut k3 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:596:25
[INFO] [stderr]     |
[INFO] [stderr] 596 |                     let mut k1 = link_left(Rc::clone(&k3), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:597:25
[INFO] [stderr]     |
[INFO] [stderr] 597 |                     let mut k2 = link_right(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:598:25
[INFO] [stderr]     |
[INFO] [stderr] 598 |                     let mut b = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:599:25
[INFO] [stderr]     |
[INFO] [stderr] 599 |                     let mut c = link_right(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: 20 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 2.00s
[INFO] running `"docker" "inspect" "1ec586979f431c8bcb544b017ed4fef53e42be0b748e66da2fe62c4eb88a07f9"`
[INFO] running `"docker" "rm" "-f" "1ec586979f431c8bcb544b017ed4fef53e42be0b748e66da2fe62c4eb88a07f9"`
[INFO] [stdout] 1ec586979f431c8bcb544b017ed4fef53e42be0b748e66da2fe62c4eb88a07f9
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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=warn" "-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" "+1.44.0" "test" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 91dbeee47200c46b03ef9e248c85892cf0b2de74f3aaec3eb78d3e5c1ce19b6f
[INFO] running `"docker" "start" "-a" "91dbeee47200c46b03ef9e248c85892cf0b2de74f3aaec3eb78d3e5c1ce19b6f"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr] warning: unused import: `tree::*`
[INFO] [stderr]  --> src/main.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use tree::*;
[INFO] [stderr]   |     ^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `cur_p`
[INFO] [stderr]    --> src/tree.rs:434:21
[INFO] [stderr]     |
[INFO] [stderr] 434 |                 let cur_p = cur.as_ptr();
[INFO] [stderr]     |                     ^^^^^ help: if this is intentional, prefix it with an underscore: `_cur_p`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:555:25
[INFO] [stderr]     |
[INFO] [stderr] 555 |                     let mut k1 = Rc::clone(&root);
[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: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:556:25
[INFO] [stderr]     |
[INFO] [stderr] 556 |                     let mut k2 = link_right(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:557:25
[INFO] [stderr]     |
[INFO] [stderr] 557 |                     let mut y = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:567:25
[INFO] [stderr]     |
[INFO] [stderr] 567 |                     let mut k1 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::search::*`
[INFO] [stderr]    --> src/tree.rs:655:13
[INFO] [stderr]     |
[INFO] [stderr] 655 |         use super::search::*;
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:568:25
[INFO] [stderr]     |
[INFO] [stderr] 568 |                     let mut k3 = link_left(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `tree::*`
[INFO] [stderr]  --> src/main.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use tree::*;
[INFO] [stderr]   |     ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:569:25
[INFO] [stderr]     |
[INFO] [stderr] 569 |                     let mut k2 = link_right(Rc::clone(&k3), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::search`
[INFO] [stderr]    --> src/tree.rs:623:13
[INFO] [stderr]     |
[INFO] [stderr] 623 |         use super::search::*;
[INFO] [stderr]     |             ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:570:25
[INFO] [stderr]     |
[INFO] [stderr] 570 |                     let mut b = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:571:25
[INFO] [stderr]     |
[INFO] [stderr] 571 |                     let mut c = link_right(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `cur_p`
[INFO] [stderr]    --> src/tree.rs:434:21
[INFO] [stderr]     |
[INFO] [stderr] 434 |                 let cur_p = cur.as_ptr();
[INFO] [stderr]     |                     ^^^^^ help: if this is intentional, prefix it with an underscore: `_cur_p`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:583:25
[INFO] [stderr]     |
[INFO] [stderr] 583 |                     let mut k2 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:584:25
[INFO] [stderr]     |
[INFO] [stderr] 584 |                     let mut k1 = link_left(Rc::clone(&k2), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:555:25
[INFO] [stderr]     |
[INFO] [stderr] 555 |                     let mut k1 = Rc::clone(&root);
[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: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:585:25
[INFO] [stderr]     |
[INFO] [stderr] 585 |                     let mut y = link_left(Rc::clone(&k1), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:595:25
[INFO] [stderr]     |
[INFO] [stderr] 595 |                     let mut k3 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:556:25
[INFO] [stderr]     |
[INFO] [stderr] 556 |                     let mut k2 = link_right(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:596:25
[INFO] [stderr]     |
[INFO] [stderr] 596 |                     let mut k1 = link_left(Rc::clone(&k3), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:557:25
[INFO] [stderr]     |
[INFO] [stderr] 557 |                     let mut y = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:597:25
[INFO] [stderr]     |
[INFO] [stderr] 597 |                     let mut k2 = link_right(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:567:25
[INFO] [stderr]     |
[INFO] [stderr] 567 |                     let mut k1 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:598:25
[INFO] [stderr]     |
[INFO] [stderr] 598 |                     let mut b = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:599:25
[INFO] [stderr]     |
[INFO] [stderr] 599 |                     let mut c = link_right(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:568:25
[INFO] [stderr]     |
[INFO] [stderr] 568 |                     let mut k3 = link_left(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/tree.rs:46:9
[INFO] [stderr]    |
[INFO] [stderr] 46 |         pub fn new(key: String, value: V) -> Self {
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `depth`
[INFO] [stderr]   --> src/tree.rs:56:9
[INFO] [stderr]    |
[INFO] [stderr] 56 |         pub fn depth(&self) -> i32 {
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:569:25
[INFO] [stderr]     |
[INFO] [stderr] 569 |                     let mut k2 = link_right(Rc::clone(&k3), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `dumps`
[INFO] [stderr]    --> src/tree.rs:316:12
[INFO] [stderr]     |
[INFO] [stderr] 316 |     pub fn dumps<V: Clone + Display>(node: Rc<RefCell<BinaryNode<V>>>, level: i32) {
[INFO] [stderr]     |            ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]    --> src/tree.rs:473:9
[INFO] [stderr]     |
[INFO] [stderr] 473 |         pub fn new() -> Self { Self { root: None } }
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:570:25
[INFO] [stderr]     |
[INFO] [stderr] 570 |                     let mut b = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `min_val`
[INFO] [stderr]    --> src/tree.rs:475:9
[INFO] [stderr]     |
[INFO] [stderr] 475 |         pub fn min_val(&self) -> Option<Rc<RefCell<V>>> {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `min_val_clone`
[INFO] [stderr]    --> src/tree.rs:493:9
[INFO] [stderr]     |
[INFO] [stderr] 493 |         pub fn min_val_clone(&self) -> Option<V> {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:571:25
[INFO] [stderr]     |
[INFO] [stderr] 571 |                     let mut c = link_right(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `max_val`
[INFO] [stderr]    --> src/tree.rs:500:9
[INFO] [stderr]     |
[INFO] [stderr] 500 |         pub fn max_val(&self) -> Option<Rc<RefCell<V>>> {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `max_val_clone`
[INFO] [stderr]    --> src/tree.rs:518:9
[INFO] [stderr]     |
[INFO] [stderr] 518 |         pub fn max_val_clone(&self) -> Option<V> {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:583:25
[INFO] [stderr]     |
[INFO] [stderr] 583 |                     let mut k2 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `height`
[INFO] [stderr]    --> src/tree.rs:525:9
[INFO] [stderr]     |
[INFO] [stderr] 525 |         pub fn height(&self) -> i32 {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 27 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:584:25
[INFO] [stderr]     |
[INFO] [stderr] 584 |                     let mut k1 = link_left(Rc::clone(&k2), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:585:25
[INFO] [stderr]     |
[INFO] [stderr] 585 |                     let mut y = link_left(Rc::clone(&k1), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:595:25
[INFO] [stderr]     |
[INFO] [stderr] 595 |                     let mut k3 = Rc::clone(&root);
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:596:25
[INFO] [stderr]     |
[INFO] [stderr] 596 |                     let mut k1 = link_left(Rc::clone(&k3), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:597:25
[INFO] [stderr]     |
[INFO] [stderr] 597 |                     let mut k2 = link_right(Rc::clone(&k1), None).unwrap();
[INFO] [stderr]     |                         ----^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:598:25
[INFO] [stderr]     |
[INFO] [stderr] 598 |                     let mut b = link_left(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/tree.rs:599:25
[INFO] [stderr]     |
[INFO] [stderr] 599 |                     let mut c = link_right(Rc::clone(&k2), None);
[INFO] [stderr]     |                         ----^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: 20 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.07s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/rust_study-0db4c6d4db3ab80c
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/t-cc8feb1b4aa628b8
[INFO] [stdout] 
[INFO] [stdout] running 3 tests
[INFO] [stdout] test tree::tests::link_test ... ok
[INFO] [stdout] test tree::tests::create_avl_tree ... ok
[INFO] [stdout] test tree::tests::binary_node ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 3 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] [stdout] test test ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `"docker" "inspect" "91dbeee47200c46b03ef9e248c85892cf0b2de74f3aaec3eb78d3e5c1ce19b6f"`
[INFO] running `"docker" "rm" "-f" "91dbeee47200c46b03ef9e248c85892cf0b2de74f3aaec3eb78d3e5c1ce19b6f"`
[INFO] [stdout] 91dbeee47200c46b03ef9e248c85892cf0b2de74f3aaec3eb78d3e5c1ce19b6f