[INFO] updating cached repository https://github.com/modulitos/CtCI-rust
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 8bbaa49c3eca43a77cf1a2cea1b6f98071ad2c78
[INFO] checking modulitos/CtCI-rust against master#3dbade652ed8ebac70f903e01f51cd92c4e4302c for pr-69880
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmodulitos%2FCtCI-rust" "/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/modulitos/CtCI-rust on toolchain 3dbade652ed8ebac70f903e01f51cd92c4e4302c
[INFO] running `"/workspace/cargo-home/bin/cargo" "+3dbade652ed8ebac70f903e01f51cd92c4e4302c" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/modulitos/CtCI-rust
[INFO] finished tweaking git repo https://github.com/modulitos/CtCI-rust
[INFO] tweaked toml for git repo https://github.com/modulitos/CtCI-rust written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/modulitos/CtCI-rust already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+3dbade652ed8ebac70f903e01f51cd92c4e4302c" "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=forbid" "-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" "+3dbade652ed8ebac70f903e01f51cd92c4e4302c" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 06c4337019492b745b7fe721aab0d4a05deede47600f842d9c12c70f7594a58e
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `"docker" "start" "-a" "06c4337019492b745b7fe721aab0d4a05deede47600f842d9c12c70f7594a58e"`
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]    Compiling regex v1.3.1
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking rand v0.7.2
[INFO] [stderr]    Compiling derive_more v0.15.0
[INFO] [stderr]     Checking rust-solutions v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unnecessary parentheses around type
[INFO] [stderr]   --> src/linked_list/second.rs:11:27
[INFO] [stderr]    |
[INFO] [stderr] 11 | pub type Link<T> = Option<(Box<Node<T>>)>;
[INFO] [stderr]    |                           ^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::List`
[INFO] [stderr]    --> src/linked_list/second.rs:167:9
[INFO] [stderr]     |
[INFO] [stderr] 167 |     use super::List;
[INFO] [stderr]     |         ^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::collections::HashSet`
[INFO] [stderr]  --> src/linked_list/third.rs:1:5
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::collections::HashSet;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::collections::HashSet`
[INFO] [stderr]  --> src/linked_list/fifth.rs:3:5
[INFO] [stderr]   |
[INFO] [stderr] 3 | use std::collections::HashSet;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::collections::HashSet`
[INFO] [stderr]  --> src/linked_list/refcell_singly.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::collections::HashSet;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]    --> src/stack.rs:115:9
[INFO] [stderr]     |
[INFO] [stderr] 115 |     use super::*;
[INFO] [stderr]     |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]    --> src/binary_search_tree.rs:124:9
[INFO] [stderr]     |
[INFO] [stderr] 124 |     use super::*;
[INFO] [stderr]     |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `Ord`, `Ordering`
[INFO] [stderr]  --> src/graph.rs:1:16
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::cmp::{Ord, Ordering};
[INFO] [stderr]   |                ^^^  ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]    --> src/graph.rs:178:9
[INFO] [stderr]     |
[INFO] [stderr] 178 |     use super::*;
[INFO] [stderr]     |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]   --> src/binary_tree.rs:43:9
[INFO] [stderr]    |
[INFO] [stderr] 43 |     use super::*;
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]   --> src/binary_tree_refcell.rs:51:9
[INFO] [stderr]    |
[INFO] [stderr] 51 |     use super::*;
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]    --> src/binary_search_tree_refcell.rs:128:9
[INFO] [stderr]     |
[INFO] [stderr] 128 |     use super::*;
[INFO] [stderr]     |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around type
[INFO] [stderr]   --> src/linked_list/second.rs:11:27
[INFO] [stderr]    |
[INFO] [stderr] 11 | pub type Link<T> = Option<(Box<Node<T>>)>;
[INFO] [stderr]    |                           ^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::collections::HashSet`
[INFO] [stderr]  --> src/linked_list/third.rs:1:5
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::collections::HashSet;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::collections::HashSet`
[INFO] [stderr]  --> src/linked_list/fifth.rs:3:5
[INFO] [stderr]   |
[INFO] [stderr] 3 | use std::collections::HashSet;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `Ord`, `Ordering`
[INFO] [stderr]  --> src/graph.rs:1:16
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::cmp::{Ord, Ordering};
[INFO] [stderr]   |                ^^^  ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/linked_list/second.rs:67:5
[INFO] [stderr]    |
[INFO] [stderr] 67 |     pub fn new() -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `into_iter`
[INFO] [stderr]   --> src/linked_list/second.rs:71:5
[INFO] [stderr]    |
[INFO] [stderr] 71 |     pub fn into_iter(self) -> IntoIter<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `iter`
[INFO] [stderr]   --> src/linked_list/second.rs:76:5
[INFO] [stderr]    |
[INFO] [stderr] 76 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `iter_mut`
[INFO] [stderr]   --> src/linked_list/second.rs:84:5
[INFO] [stderr]    |
[INFO] [stderr] 84 |     pub fn iter_mut(&mut self) -> IterMut<'_, T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `push`
[INFO] [stderr]   --> src/linked_list/second.rs:90:5
[INFO] [stderr]    |
[INFO] [stderr] 90 |     pub fn push(&mut self, elem: T) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `peek`
[INFO] [stderr]    --> src/linked_list/second.rs:119:5
[INFO] [stderr]     |
[INFO] [stderr] 119 |     pub fn peek(&self) -> Option<&T> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `peek_mut`
[INFO] [stderr]    --> src/linked_list/second.rs:123:5
[INFO] [stderr]     |
[INFO] [stderr] 123 |     pub fn peek_mut(&mut self) -> Option<&mut T> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/linked_list/third.rs:21:5
[INFO] [stderr]    |
[INFO] [stderr] 21 |     pub fn new() -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `append`
[INFO] [stderr]   --> src/linked_list/third.rs:25:5
[INFO] [stderr]    |
[INFO] [stderr] 25 |     pub fn append(&mut self, elem: T) -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `tail`
[INFO] [stderr]   --> src/linked_list/third.rs:35:5
[INFO] [stderr]    |
[INFO] [stderr] 35 |     pub fn tail(&self) -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `head`
[INFO] [stderr]   --> src/linked_list/third.rs:40:5
[INFO] [stderr]    |
[INFO] [stderr] 40 |     pub fn head(&self) -> Option<&T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `iter`
[INFO] [stderr]    --> src/linked_list/third.rs:107:5
[INFO] [stderr]     |
[INFO] [stderr] 107 |     pub fn iter(&self) -> Iter<'_, T> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/linked_list/fourth.rs:19:5
[INFO] [stderr]    |
[INFO] [stderr] 19 |     fn new(elem: T) -> Rc<RefCell<Self>> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/linked_list/fourth.rs:29:5
[INFO] [stderr]    |
[INFO] [stderr] 29 |     pub fn new() -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `push_front`
[INFO] [stderr]   --> src/linked_list/fourth.rs:35:5
[INFO] [stderr]    |
[INFO] [stderr] 35 |     pub fn push_front(&mut self, elem: T) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `peek_front`
[INFO] [stderr]   --> src/linked_list/fourth.rs:76:5
[INFO] [stderr]    |
[INFO] [stderr] 76 |     pub fn peek_front(&self) -> Option<Ref<T>> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `prev`
[INFO] [stderr]   --> src/linked_list/brandon.rs:25:5
[INFO] [stderr]    |
[INFO] [stderr] 25 |     prev: Option<NodeRef<T>>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `tail`
[INFO] [stderr]   --> src/linked_list/brandon.rs:39:5
[INFO] [stderr]    |
[INFO] [stderr] 39 |     fn tail(node: &NodeRef<T>) -> Option<NodeRef<T>> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `remove`
[INFO] [stderr]   --> src/linked_list/brandon.rs:46:5
[INFO] [stderr]    |
[INFO] [stderr] 46 |     fn remove(&mut self) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/linked_list/brandon.rs:64:5
[INFO] [stderr]    |
[INFO] [stderr] 64 |     fn new() -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `append`
[INFO] [stderr]   --> src/linked_list/brandon.rs:68:5
[INFO] [stderr]    |
[INFO] [stderr] 68 |     fn append(&mut self, new_value: T) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `tail`
[INFO] [stderr]   --> src/linked_list/brandon.rs:85:5
[INFO] [stderr]    |
[INFO] [stderr] 85 |     fn tail(&self) -> Option<NodeRef<T>> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `iter`
[INFO] [stderr]   --> src/linked_list/brandon.rs:96:5
[INFO] [stderr]    |
[INFO] [stderr] 96 |     fn iter(&self) -> Iter<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `list_has_duplicates`
[INFO] [stderr]    --> src/linked_list/brandon.rs:102:5
[INFO] [stderr]     |
[INFO] [stderr] 102 |     fn list_has_duplicates(&self) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `remove_duplicates`
[INFO] [stderr]    --> src/linked_list/brandon.rs:117:5
[INFO] [stderr]     |
[INFO] [stderr] 117 |     fn remove_duplicates(&mut self) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/linked_list/brandon.rs:228:4
[INFO] [stderr]     |
[INFO] [stderr] 228 | fn main() {
[INFO] [stderr]     |    ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/linked_list/fifth.rs:24:5
[INFO] [stderr]    |
[INFO] [stderr] 24 |     pub fn new() -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `push`
[INFO] [stderr]   --> src/linked_list/fifth.rs:31:5
[INFO] [stderr]    |
[INFO] [stderr] 31 |     pub fn push(&mut self, elem: T) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `pop`
[INFO] [stderr]   --> src/linked_list/fifth.rs:53:5
[INFO] [stderr]    |
[INFO] [stderr] 53 |     pub fn pop(&mut self) -> Option<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `BTreeNode as Node`, `BinaryTree`
[INFO] [stderr]   --> src/bin/ch4-p10_check-subtree.rs:11:31
[INFO] [stderr]    |
[INFO] [stderr] 11 | use cracking::{BTree as Tree, BTreeNode as Node, BinaryTree};
[INFO] [stderr]    |                               ^^^^^^^^^^^^^^^^^  ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]   --> src/bin/ch4-p10_check-subtree.rs:66:9
[INFO] [stderr]    |
[INFO] [stderr] 66 |     use super::*;
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0601]: `main` function not found in crate `ch4_p10_check_subtree`
[INFO] [stderr]    --> src/bin/ch4-p10_check-subtree.rs:11:1
[INFO] [stderr]     |
[INFO] [stderr] 11  | / use cracking::{BTree as Tree, BTreeNode as Node, BinaryTree};
[INFO] [stderr] 12  | |
[INFO] [stderr] 13  | | // Uses a string comparison approach - serialize the trees into
[INFO] [stderr] 14  | | // strings, then check whether the substree's string is contained
[INFO] [stderr] ...   |
[INFO] [stderr] 124 | |     }
[INFO] [stderr] 125 | | }
[INFO] [stderr]     | |_^ consider adding a `main` function to `src/bin/ch4-p10_check-subtree.rs`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0601`.
[INFO] [stderr] error: could not compile `rust-solutions`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] warning: unused import: `Node`
[INFO] [stderr]   --> src/bin/ch2-p7_check-intersection.rs:11:48
[INFO] [stderr]    |
[INFO] [stderr] 11 | use cracking::{SinglyLinkedList as LinkedList, Node};
[INFO] [stderr]    |                                                ^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::cell::RefCell`
[INFO] [stderr]   --> src/bin/ch2-p7_check-intersection.rs:14:5
[INFO] [stderr]    |
[INFO] [stderr] 14 | use std::cell::RefCell;
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]   --> src/bin/ch2-p7_check-intersection.rs:56:9
[INFO] [stderr]    |
[INFO] [stderr] 56 |     use super::*;
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0601]: `main` function not found in crate `ch2_p7_check_intersection`
[INFO] [stderr]    --> src/bin/ch2-p7_check-intersection.rs:10:1
[INFO] [stderr]     |
[INFO] [stderr] 10  | / extern crate cracking;
[INFO] [stderr] 11  | | use cracking::{SinglyLinkedList as LinkedList, Node};
[INFO] [stderr] 12  | |
[INFO] [stderr] 13  | | use std::rc::Rc;
[INFO] [stderr] ...   |
[INFO] [stderr] 145 | |     }
[INFO] [stderr] 146 | | }
[INFO] [stderr]     | |_^ consider adding a `main` function to `src/bin/ch2-p7_check-intersection.rs`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0601`.
[INFO] [stderr] error: could not compile `rust-solutions`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] warning: unused import: `TreeNode`
[INFO] [stderr]  --> src/bin/ch4-p5_validate-bst.rs:8:40
[INFO] [stderr]   |
[INFO] [stderr] 8 | use cracking::{BinarySearchTree, Tree, TreeNode};
[INFO] [stderr]   |                                        ^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]   --> src/bin/ch4-p5_validate-bst.rs:88:9
[INFO] [stderr]    |
[INFO] [stderr] 88 |     use super::*;
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0601]: `main` function not found in crate `ch4_p5_validate_bst`
[INFO] [stderr]    --> src/bin/ch4-p5_validate-bst.rs:8:1
[INFO] [stderr]     |
[INFO] [stderr] 8   | / use cracking::{BinarySearchTree, Tree, TreeNode};
[INFO] [stderr] 9   | |
[INFO] [stderr] 10  | | trait ValidateBST<T> {
[INFO] [stderr] 11  | |     fn validate_bst(&self) -> bool;
[INFO] [stderr] ...   |
[INFO] [stderr] 192 | |     }
[INFO] [stderr] 193 | | }
[INFO] [stderr]     | |_^ consider adding a `main` function to `src/bin/ch4-p5_validate-bst.rs`
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `RCBTreeNode as Node`
[INFO] [stderr]  --> src/bin/ch4-p8_first-common-ancestor.rs:6:33
[INFO] [stderr]   |
[INFO] [stderr] 6 | use cracking::{RCBTree as Tree, RCBTreeNode as Node, RCBinaryTree as BinaryTree};
[INFO] [stderr]   |                                 ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]    --> src/bin/ch4-p8_first-common-ancestor.rs:104:9
[INFO] [stderr]     |
[INFO] [stderr] 104 |     use super::*;
[INFO] [stderr]     |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0601]: `main` function not found in crate `ch4_p8_first_common_ancestor`
[INFO] [stderr]    --> src/bin/ch4-p8_first-common-ancestor.rs:6:1
[INFO] [stderr]     |
[INFO] [stderr] 6   | / use cracking::{RCBTree as Tree, RCBTreeNode as Node, RCBinaryTree as BinaryTree};
[INFO] [stderr] 7   | | use std::rc::Rc;
[INFO] [stderr] 8   | |
[INFO] [stderr] 9   | | trait FirstCommonAncestor<T> {
[INFO] [stderr] ...   |
[INFO] [stderr] 242 | |     }
[INFO] [stderr] 243 | | }
[INFO] [stderr]     | |_^ consider adding a `main` function to `src/bin/ch4-p8_first-common-ancestor.rs`
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `urlify_2`
[INFO] [stderr]   --> src/bin/ch1-p2_urlify.rs:36:4
[INFO] [stderr]    |
[INFO] [stderr] 36 | fn urlify_2(url: &str) -> String {
[INFO] [stderr]    |    ^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]   --> src/bin/ch4-p1_route-between-nodes.rs:68:9
[INFO] [stderr]    |
[INFO] [stderr] 68 |     use super::*;
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] error[E0601]: `main` function not found in crate `ch4_p1_route_between_nodes`
[INFO] [stderr]    --> src/bin/ch4-p1_route-between-nodes.rs:4:1
[INFO] [stderr]     |
[INFO] [stderr] 4   | / use std::collections::HashSet;
[INFO] [stderr] 5   | | use std::collections::VecDeque;
[INFO] [stderr] 6   | |
[INFO] [stderr] 7   | | struct ASimpleGraph {
[INFO] [stderr] ...   |
[INFO] [stderr] 110 | |     }
[INFO] [stderr] 111 | | }
[INFO] [stderr]     | |_^ consider adding a `main` function to `src/bin/ch4-p1_route-between-nodes.rs`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0601`.
[INFO] [stderr] error: could not compile `rust-solutions`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0601`.
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0601`.
[INFO] [stderr] error: could not compile `rust-solutions`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `rust-solutions`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/stack.rs:153:13
[INFO] [stderr]     |
[INFO] [stderr] 153 |         let mut s: Stack<u64> = Stack::new();
[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: method is never used: `list_has_duplicates`
[INFO] [stderr]    --> src/linked_list/brandon.rs:102:5
[INFO] [stderr]     |
[INFO] [stderr] 102 |     fn list_has_duplicates(&self) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/linked_list/brandon.rs:228:4
[INFO] [stderr]     |
[INFO] [stderr] 228 | fn main() {
[INFO] [stderr]     |    ^^^^
[INFO] [stderr] 
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "06c4337019492b745b7fe721aab0d4a05deede47600f842d9c12c70f7594a58e"`
[INFO] running `"docker" "rm" "-f" "06c4337019492b745b7fe721aab0d4a05deede47600f842d9c12c70f7594a58e"`
[INFO] [stdout] 06c4337019492b745b7fe721aab0d4a05deede47600f842d9c12c70f7594a58e