[INFO] cloning repository https://github.com/johnshift/rust-ds
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/johnshift/rust-ds" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjohnshift%2Frust-ds", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjohnshift%2Frust-ds'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 4d0eb5cce1c49d5ec54312864f1ba295722b6432
[INFO] checking johnshift/rust-ds against master#0599f3403366d9c57f0625e6de3af214b5042a90 for pr-87710
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjohnshift%2Frust-ds" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/johnshift/rust-ds on toolchain 0599f3403366d9c57f0625e6de3af214b5042a90
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0599f3403366d9c57f0625e6de3af214b5042a90" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/johnshift/rust-ds
[INFO] finished tweaking git repo https://github.com/johnshift/rust-ds
[INFO] tweaked toml for git repo https://github.com/johnshift/rust-ds written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/johnshift/rust-ds already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0599f3403366d9c57f0625e6de3af214b5042a90" "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] [stderr]  Downloading crates ...
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[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+0599f3403366d9c57f0625e6de3af214b5042a90" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] e3cfaf8034207ee65fc3b45e9c1b90f3c658171f1b9b84cb783b9b2584563f63
[INFO] running `Command { std: "docker" "start" "-a" "e3cfaf8034207ee65fc3b45e9c1b90f3c658171f1b9b84cb783b9b2584563f63", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e3cfaf8034207ee65fc3b45e9c1b90f3c658171f1b9b84cb783b9b2584563f63", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e3cfaf8034207ee65fc3b45e9c1b90f3c658171f1b9b84cb783b9b2584563f63", kill_on_drop: false }`
[INFO] [stdout] e3cfaf8034207ee65fc3b45e9c1b90f3c658171f1b9b84cb783b9b2584563f63
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "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" "+0599f3403366d9c57f0625e6de3af214b5042a90" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] c6441160989b94e5094a602c65379ed78ce78787d500ffe629467ec8ac092759
[INFO] running `Command { std: "docker" "start" "-a" "c6441160989b94e5094a602c65379ed78ce78787d500ffe629467ec8ac092759", kill_on_drop: false }`
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]    Compiling crossbeam-utils v0.8.5
[INFO] [stderr]    Compiling libc v0.2.99
[INFO] [stderr]    Compiling proc-macro2 v1.0.28
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.5
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]    Compiling rayon-core v1.9.1
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]    Compiling serde_json v1.0.66
[INFO] [stderr]     Checking either v1.6.1
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]     Checking unicode-width v0.1.8
[INFO] [stderr]    Compiling serde_derive v1.0.127
[INFO] [stderr]     Checking half v1.7.1
[INFO] [stderr]     Checking bitflags v1.3.2
[INFO] [stderr]     Checking hashmap v0.1.0 (/opt/rustwide/workdir/hashmap)
[INFO] [stderr]     Checking ref-deref v0.1.0 (/opt/rustwide/workdir/ref-deref)
[INFO] [stderr]     Checking stacks-queues v0.1.0 (/opt/rustwide/workdir/stacks-queues)
[INFO] [stderr]     Checking linked-list v0.1.0 (/opt/rustwide/workdir/linked-list)
[INFO] [stderr]     Checking iterators v0.1.0 (/opt/rustwide/workdir/iterators)
[INFO] [stderr]     Checking fntools v0.1.0 (/opt/rustwide/workdir/fntools)
[INFO] [stderr]     Checking smart-pointers v0.1.0 (/opt/rustwide/workdir/smart-pointers)
[INFO] [stdout] warning: unused variable: `length`
[INFO] [stdout]   --> stacks-queues/src/stacks.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let length = self.elements.len();
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_length`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `TODO`
[INFO] [stdout]  --> ref-deref/src/lib.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 8 | struct TODO;
[INFO] [stdout]   |        ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Queue`
[INFO] [stdout]  --> stacks-queues/src/queues.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | struct Queue<T> {
[INFO] [stdout]   |        ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> stacks-queues/src/queues.rs:10:6
[INFO] [stdout]    |
[INFO] [stdout] 10 |   fn new() -> Self {
[INFO] [stdout]    |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `peek`
[INFO] [stdout]   --> stacks-queues/src/queues.rs:17:6
[INFO] [stdout]    |
[INFO] [stdout] 17 |   fn peek(&self) -> Option<&T> {
[INFO] [stdout]    |      ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `enqueue`
[INFO] [stdout]   --> stacks-queues/src/queues.rs:22:6
[INFO] [stdout]    |
[INFO] [stdout] 22 |   fn enqueue(&mut self, value: T) {
[INFO] [stdout]    |      ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `dequeue`
[INFO] [stdout]   --> stacks-queues/src/queues.rs:28:6
[INFO] [stdout]    |
[INFO] [stdout] 28 |   fn dequeue(&mut self) -> Option<T> {
[INFO] [stdout]    |      ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Stack`
[INFO] [stdout]  --> stacks-queues/src/stacks.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct Stack<T> {
[INFO] [stdout]   |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]  --> stacks-queues/src/stacks.rs:8:6
[INFO] [stdout]   |
[INFO] [stdout] 8 |   fn new() -> Self {
[INFO] [stdout]   |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `peek`
[INFO] [stdout]   --> stacks-queues/src/stacks.rs:15:6
[INFO] [stdout]    |
[INFO] [stdout] 15 |   fn peek(&self) -> Option<&T> {
[INFO] [stdout]    |      ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `push`
[INFO] [stdout]   --> stacks-queues/src/stacks.rs:25:6
[INFO] [stdout]    |
[INFO] [stdout] 25 |   fn push(&mut self, value: T) {
[INFO] [stdout]    |      ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `pop`
[INFO] [stdout]   --> stacks-queues/src/stacks.rs:30:6
[INFO] [stdout]    |
[INFO] [stdout] 30 |   fn pop(&mut self) -> Option<T> {
[INFO] [stdout]    |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 11 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `length`
[INFO] [stdout]   --> stacks-queues/src/stacks.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let length = self.elements.len();
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_length`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `TODO`
[INFO] [stdout]  --> ref-deref/src/lib.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 8 | struct TODO;
[INFO] [stdout]   |        ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking array v0.1.0 (/opt/rustwide/workdir/array)
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking trees v0.1.0 (/opt/rustwide/workdir/trees)
[INFO] [stdout] warning: field is never read: `value`
[INFO] [stdout]   --> linked-list/src/bad_linked_list.rs:17:3
[INFO] [stdout]    |
[INFO] [stdout] 17 |   value: i32, // 4 bytes
[INFO] [stdout]    |   ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `next`
[INFO] [stdout]   --> linked-list/src/bad_linked_list.rs:18:3
[INFO] [stdout]    |
[INFO] [stdout] 18 |   next: Link, // 8 bytes
[INFO] [stdout]    |   ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `head`
[INFO] [stdout]   --> linked-list/src/bad_linked_list.rs:23:3
[INFO] [stdout]    |
[INFO] [stdout] 23 |   head: Link, // Link -> 8 bytes
[INFO] [stdout]    |   ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> linked-list/src/bad_linked_list.rs:27:6
[INFO] [stdout]    |
[INFO] [stdout] 27 |   fn new() -> Self {
[INFO] [stdout]    |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `prepend`
[INFO] [stdout]   --> linked-list/src/bad_linked_list.rs:32:6
[INFO] [stdout]    |
[INFO] [stdout] 32 |   fn prepend(&mut self, value: i32) {
[INFO] [stdout]    |      ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `pop`
[INFO] [stdout]   --> linked-list/src/bad_linked_list.rs:51:6
[INFO] [stdout]    |
[INFO] [stdout] 51 |   fn pop(&mut self) -> Option<i32> {
[INFO] [stdout]    |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> linked-list/src/better_linked_list.rs:15:6
[INFO] [stdout]    |
[INFO] [stdout] 15 |   fn new() -> Self {
[INFO] [stdout]    |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `prepend`
[INFO] [stdout]   --> linked-list/src/better_linked_list.rs:21:6
[INFO] [stdout]    |
[INFO] [stdout] 21 |   fn prepend(&self, value: T) -> List<T> {
[INFO] [stdout]    |      ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `tail`
[INFO] [stdout]   --> linked-list/src/better_linked_list.rs:31:6
[INFO] [stdout]    |
[INFO] [stdout] 31 |   fn tail(&self) -> List<T> {
[INFO] [stdout]    |      ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `head`
[INFO] [stdout]   --> linked-list/src/better_linked_list.rs:38:6
[INFO] [stdout]    |
[INFO] [stdout] 38 |   fn head(&self) -> Option<&T> {
[INFO] [stdout]    |      ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> linked-list/src/ok_linked_list.rs:16:6
[INFO] [stdout]    |
[INFO] [stdout] 16 |   fn new() -> Self {
[INFO] [stdout]    |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `prepend`
[INFO] [stdout]   --> linked-list/src/ok_linked_list.rs:20:6
[INFO] [stdout]    |
[INFO] [stdout] 20 |   fn prepend(&mut self, value: T) {
[INFO] [stdout]    |      ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `peek`
[INFO] [stdout]   --> linked-list/src/ok_linked_list.rs:40:6
[INFO] [stdout]    |
[INFO] [stdout] 40 |   fn peek(&self) -> Option<&T> {
[INFO] [stdout]    |      ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `peek_mut`
[INFO] [stdout]   --> linked-list/src/ok_linked_list.rs:45:6
[INFO] [stdout]    |
[INFO] [stdout] 45 |   fn peek_mut(&mut self) -> Option<&mut T> {
[INFO] [stdout]    |      ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `SinglyLinkedList`
[INFO] [stdout]   --> linked-list/src/lib.rs:24:8
[INFO] [stdout]    |
[INFO] [stdout] 24 | struct SinglyLinkedList<T> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> linked-list/src/lib.rs:29:6
[INFO] [stdout]    |
[INFO] [stdout] 29 |   fn new(value: T) -> Self {
[INFO] [stdout]    |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `len`
[INFO] [stdout]   --> linked-list/src/lib.rs:35:6
[INFO] [stdout]    |
[INFO] [stdout] 35 |   fn len(&self) -> usize {
[INFO] [stdout]    |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `head`
[INFO] [stdout]   --> linked-list/src/lib.rs:42:6
[INFO] [stdout]    |
[INFO] [stdout] 42 |   fn head(&self) -> Option<&T> {
[INFO] [stdout]    |      ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `tail`
[INFO] [stdout]   --> linked-list/src/lib.rs:52:6
[INFO] [stdout]    |
[INFO] [stdout] 52 |   fn tail(&self) -> Option<&T> {
[INFO] [stdout]    |      ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `append`
[INFO] [stdout]   --> linked-list/src/lib.rs:61:6
[INFO] [stdout]    |
[INFO] [stdout] 61 |   fn append(&mut self, value: T) {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `prepend`
[INFO] [stdout]   --> linked-list/src/lib.rs:66:6
[INFO] [stdout]    |
[INFO] [stdout] 66 |   fn prepend(&mut self, value: T) {
[INFO] [stdout]    |      ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `insert`
[INFO] [stdout]   --> linked-list/src/lib.rs:73:6
[INFO] [stdout]    |
[INFO] [stdout] 73 |   fn insert(&mut self, index: usize, value: T) {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `remove`
[INFO] [stdout]   --> linked-list/src/lib.rs:78:6
[INFO] [stdout]    |
[INFO] [stdout] 78 |   fn remove(&mut self, index: usize) {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `reverse`
[INFO] [stdout]   --> linked-list/src/lib.rs:83:6
[INFO] [stdout]    |
[INFO] [stdout] 83 |   fn reverse(&mut self) {
[INFO] [stdout]    |      ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `TODO`
[INFO] [stdout]   --> iterators/src/lib.rs:19:8
[INFO] [stdout]    |
[INFO] [stdout] 19 | struct TODO;
[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] [stdout] warning: 24 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `TODO`
[INFO] [stdout]   --> iterators/src/lib.rs:19:8
[INFO] [stdout]    |
[INFO] [stdout] 19 | struct TODO;
[INFO] [stdout]    |        ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `list`
[INFO] [stdout]   --> smart-pointers/src/boxx.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let list = Cons(1, Box::new(Cons(2, Box::new(Cons(3, Box::new(Nil))))));
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_list`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `box_demo`
[INFO] [stdout]  --> smart-pointers/src/boxx.rs:8:4
[INFO] [stdout]   |
[INFO] [stdout] 8 | fn box_demo() {
[INFO] [stdout]   |    ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `ConsList`
[INFO] [stdout]   --> smart-pointers/src/boxx.rs:20:6
[INFO] [stdout]    |
[INFO] [stdout] 20 | enum ConsList {
[INFO] [stdout]    |      ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `box_cons`
[INFO] [stdout]   --> smart-pointers/src/boxx.rs:25:4
[INFO] [stdout]    |
[INFO] [stdout] 25 | fn box_cons() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `SomeStruct`
[INFO] [stdout]   --> smart-pointers/src/cell.rs:10:8
[INFO] [stdout]    |
[INFO] [stdout] 10 | struct SomeStruct {
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]  --> smart-pointers/src/deref.rs:6:6
[INFO] [stdout]   |
[INFO] [stdout] 6 |   fn new(x: T) -> Custom<T> {
[INFO] [stdout]   |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `ConsList`
[INFO] [stdout]   --> smart-pointers/src/rc.rs:19:6
[INFO] [stdout]    |
[INFO] [stdout] 19 | enum ConsList {
[INFO] [stdout]    |      ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Cons`
[INFO] [stdout]   --> smart-pointers/src/refcell.rs:13:3
[INFO] [stdout]    |
[INFO] [stdout] 13 |   Cons(Rc<RefCell<i32>>, Rc<ConsList>),
[INFO] [stdout]    |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Nil`
[INFO] [stdout]   --> smart-pointers/src/refcell.rs:14:3
[INFO] [stdout]    |
[INFO] [stdout] 14 |   Nil,
[INFO] [stdout]    |   ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `array_exercise1`
[INFO] [stdout]  --> array/src/exercise.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn array_exercise1<T: Ord>(a1: Vec<T>, a2: Vec<T>) -> Vec<T> {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `MyArray`
[INFO] [stdout]   --> array/src/lib.rs:10:8
[INFO] [stdout]    |
[INFO] [stdout] 10 | struct MyArray<T> {
[INFO] [stdout]    |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> array/src/lib.rs:16:6
[INFO] [stdout]    |
[INFO] [stdout] 16 |   fn new(data: Vec<T>) -> Self {
[INFO] [stdout]    |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `get`
[INFO] [stdout]   --> array/src/lib.rs:23:6
[INFO] [stdout]    |
[INFO] [stdout] 23 |   fn get(&self, index: usize) -> Option<&T> {
[INFO] [stdout]    |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `push`
[INFO] [stdout]   --> array/src/lib.rs:28:6
[INFO] [stdout]    |
[INFO] [stdout] 28 |   fn push(&mut self, item: T) -> usize {
[INFO] [stdout]    |      ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `pop`
[INFO] [stdout]   --> array/src/lib.rs:35:6
[INFO] [stdout]    |
[INFO] [stdout] 35 |   fn pop(&mut self) -> Option<T> {
[INFO] [stdout]    |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `delete`
[INFO] [stdout]   --> array/src/lib.rs:40:6
[INFO] [stdout]    |
[INFO] [stdout] 40 |   fn delete(&mut self, index: usize) -> Option<T> {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `list`
[INFO] [stdout]   --> smart-pointers/src/boxx.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let list = Cons(1, Box::new(Cons(2, Box::new(Cons(3, Box::new(Nil))))));
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_list`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `d`
[INFO] [stdout]   --> smart-pointers/src/drop.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let d = Custom {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_d`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> smart-pointers/src/rc.rs:40:9
[INFO] [stdout]    |
[INFO] [stdout] 40 |     let b = Cons(3, Rc::clone(&a));
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> smart-pointers/src/rc.rs:41:9
[INFO] [stdout]    |
[INFO] [stdout] 41 |     let c = Cons(4, Rc::clone(&a));
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `ConsList`
[INFO] [stdout]   --> smart-pointers/src/boxx.rs:20:6
[INFO] [stdout]    |
[INFO] [stdout] 20 | enum ConsList {
[INFO] [stdout]    |      ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `box_cons`
[INFO] [stdout]   --> smart-pointers/src/boxx.rs:25:4
[INFO] [stdout]    |
[INFO] [stdout] 25 | fn box_cons() {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `regular_field`
[INFO] [stdout]   --> smart-pointers/src/cell.rs:11:3
[INFO] [stdout]    |
[INFO] [stdout] 11 |   regular_field: u8,
[INFO] [stdout]    |   ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling memoffset v0.6.4
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling rayon v1.5.1
[INFO] [stdout] warning: 9 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking itertools v0.10.1
[INFO] [stdout] warning: unused import: `std::borrow::BorrowMut`
[INFO] [stdout]  --> trees/src/binary_tree.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::borrow::BorrowMut;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `filter_demo`
[INFO] [stdout]  --> fntools/src/filter.rs:4:4
[INFO] [stdout]   |
[INFO] [stdout] 4 | fn filter_demo(start: usize, end: usize, x: usize) -> Vec<usize> {
[INFO] [stdout]   |    ^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `fold_startend`
[INFO] [stdout]  --> fntools/src/fold.rs:5:4
[INFO] [stdout]   |
[INFO] [stdout] 5 | fn fold_startend(start: i32, end: i32) -> i32 {
[INFO] [stdout]   |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `map_squared`
[INFO] [stdout]  --> fntools/src/map.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn map_squared(a: Vec<i32>) -> Vec<i32> {
[INFO] [stdout]   |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `reverse`
[INFO] [stdout]  --> fntools/src/rev.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn reverse<T>(arr: Vec<T>) -> Vec<T> {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `zip_demo`
[INFO] [stdout]  --> fntools/src/zip.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn zip_demo<T>(arr1: Vec<T>, arr2: Vec<T>)
[INFO] [stdout]   |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `zip_merge`
[INFO] [stdout]   --> fntools/src/zip.rs:17:8
[INFO] [stdout]    |
[INFO] [stdout] 17 | pub fn zip_merge<T>(arr1: Vec<T>, arr2: Vec<T>) -> Vec<T>
[INFO] [stdout]    |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::borrow::BorrowMut`
[INFO] [stdout]  --> trees/src/binary_tree.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::borrow::BorrowMut;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking serde_cbor v0.11.2
[INFO] [stdout] error[E0506]: cannot assign to `current_node` because it is borrowed
[INFO] [stdout]   --> trees/src/binary_tree.rs:67:15
[INFO] [stdout]    |
[INFO] [stdout] 49 |       if let Some(ref node) = current_node {
[INFO] [stdout]    |                   -------- borrow of `current_node` occurs here
[INFO] [stdout] ...
[INFO] [stdout] 53 |           match &node.borrow().left {
[INFO] [stdout]    |                  ------------- a temporary with access to the borrow is created here ...
[INFO] [stdout] ...
[INFO] [stdout] 67 |               current_node = (*n.as_ref().borrow_mut()).left;
[INFO] [stdout]    |               ^^^^^^^^^^^^ assignment to borrowed `current_node` occurs here
[INFO] [stdout] 68 |             }
[INFO] [stdout] 69 |           };
[INFO] [stdout]    |            - ... and the borrow might be used here, when that temporary is dropped and runs the destructor for type `Ref<'_, Node<T>>`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0507]: cannot move out of dereference of `RefMut<'_, Node<T>>`
[INFO] [stdout]   --> trees/src/binary_tree.rs:67:30
[INFO] [stdout]    |
[INFO] [stdout] 67 |               current_node = (*n.as_ref().borrow_mut()).left;
[INFO] [stdout]    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ move occurs because value has type `Option<Rc<RefCell<Node<T>>>>`, which does not implement the `Copy` trait
[INFO] [stdout]    |
[INFO] [stdout] help: consider borrowing the `Option`'s content
[INFO] [stdout]    |
[INFO] [stdout] 67 |               current_node = (*n.as_ref().borrow_mut()).left.as_ref();
[INFO] [stdout]    |                                                             +++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking bstr v0.2.16
[INFO] [stdout] Some errors have detailed explanations: E0506, E0507.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0506`.
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0506]: cannot assign to `current_node` because it is borrowed
[INFO] [stdout]   --> trees/src/binary_tree.rs:67:15
[INFO] [stdout]    |
[INFO] [stdout] 49 |       if let Some(ref node) = current_node {
[INFO] [stdout]    |                   -------- borrow of `current_node` occurs here
[INFO] [stdout] ...
[INFO] [stdout] 53 |           match &node.borrow().left {
[INFO] [stdout]    |                  ------------- a temporary with access to the borrow is created here ...
[INFO] [stdout] ...
[INFO] [stdout] 67 |               current_node = (*n.as_ref().borrow_mut()).left;
[INFO] [stdout]    |               ^^^^^^^^^^^^ assignment to borrowed `current_node` occurs here
[INFO] [stdout] 68 |             }
[INFO] [stdout] 69 |           };
[INFO] [stdout]    |            - ... and the borrow might be used here, when that temporary is dropped and runs the destructor for type `Ref<'_, Node<T>>`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `trees` due to 3 previous errors; 1 warning emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error[E0507]: cannot move out of dereference of `RefMut<'_, Node<T>>`
[INFO] [stdout]   --> trees/src/binary_tree.rs:67:30
[INFO] [stdout]    |
[INFO] [stdout] 67 |               current_node = (*n.as_ref().borrow_mut()).left;
[INFO] [stdout]    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ move occurs because value has type `Option<Rc<RefCell<Node<T>>>>`, which does not implement the `Copy` trait
[INFO] [stdout]    |
[INFO] [stdout] help: consider borrowing the `Option`'s content
[INFO] [stdout]    |
[INFO] [stdout] 67 |               current_node = (*n.as_ref().borrow_mut()).left.as_ref();
[INFO] [stdout]    |                                                             +++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0506, E0507.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0506`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "c6441160989b94e5094a602c65379ed78ce78787d500ffe629467ec8ac092759", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c6441160989b94e5094a602c65379ed78ce78787d500ffe629467ec8ac092759", kill_on_drop: false }`
[INFO] [stdout] c6441160989b94e5094a602c65379ed78ce78787d500ffe629467ec8ac092759