[INFO] cloning repository https://github.com/zxiang77/lc-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/zxiang77/lc-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzxiang77%2Flc-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzxiang77%2Flc-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f934f613283d466141dbb5bb8f537e7613127271
[INFO] checking zxiang77/lc-rs against try#f47dd4da3ae8c32c9e65d307bfe640b143e674df for pr-77526
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzxiang77%2Flc-rs" "/workspace/builds/worker-1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/zxiang77/lc-rs on toolchain f47dd4da3ae8c32c9e65d307bfe640b143e674df
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/zxiang77/lc-rs
[INFO] finished tweaking git repo https://github.com/zxiang77/lc-rs
[INFO] tweaked toml for git repo https://github.com/zxiang77/lc-rs written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/zxiang77/lc-rs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "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] 34577fa346567559e6cf27879919bc974647f7d347884122cddc593cdc53cf07
[INFO] running `Command { std: "docker" "start" "-a" "34577fa346567559e6cf27879919bc974647f7d347884122cddc593cdc53cf07", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "34577fa346567559e6cf27879919bc974647f7d347884122cddc593cdc53cf07", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "34577fa346567559e6cf27879919bc974647f7d347884122cddc593cdc53cf07", kill_on_drop: false }`
[INFO] [stdout] 34577fa346567559e6cf27879919bc974647f7d347884122cddc593cdc53cf07
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 508cd2ccb767d67d50845e90bb7b37cb80ad5efad2e1ba01dac7cf4963ac8b5d
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "508cd2ccb767d67d50845e90bb7b37cb80ad5efad2e1ba01dac7cf4963ac8b5d", kill_on_drop: false }`
[INFO] [stderr]     Checking lc-rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `Ref`
[INFO] [stdout]  --> src/utils/node.rs:2:26
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cell::{RefCell, Ref};
[INFO] [stdout]   |                          ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `core::borrow::Borrow`
[INFO] [stdout]  --> src/utils/node.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use core::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::HashMap`
[INFO] [stdout]  --> src/sol/q1028.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::collections::HashMap;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `core::borrow::Borrow`
[INFO] [stdout]  --> src/sol/q1028.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use core::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cell::RefCell`
[INFO] [stdout]  --> src/main.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::cell::RefCell;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `dep`
[INFO] [stdout]   --> src/sol/q1028.rs:13:20
[INFO] [stdout]    |
[INFO] [stdout] 13 |         let (node, dep, mut remain) = Solution::parse_next(&s);
[INFO] [stdout]    |                    ^^^ help: if this is intentional, prefix it with an underscore: `_dep`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/sol/q1028.rs:32:25
[INFO] [stdout]    |
[INFO] [stdout] 32 |                     let mut cur = Solution::peek(&stack);
[INFO] [stdout]    |                         ----^^^
[INFO] [stdout]    |                         |
[INFO] [stdout]    |                         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Ref`
[INFO] [stdout]  --> src/utils/node.rs:2:26
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cell::{RefCell, Ref};
[INFO] [stdout]   |                          ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `core::borrow::Borrow`
[INFO] [stdout]  --> src/utils/node.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use core::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `core::borrow::Borrow`
[INFO] [stdout]  --> src/sol/q1028.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use core::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cell::RefCell`
[INFO] [stdout]  --> src/main.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::cell::RefCell;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> src/utils/node.rs:15:12
[INFO] [stdout]    |
[INFO] [stdout] 15 |     pub fn new(val: i32) -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Solution`
[INFO] [stdout]  --> src/sol/q1028.rs:7:12
[INFO] [stdout]   |
[INFO] [stdout] 7 | pub struct Solution {
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `recover_from_preorder`
[INFO] [stdout]   --> src/sol/q1028.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 12 |     pub fn recover_from_preorder(s: String) -> Option<Rc<RefCell<TreeNode>>> {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `peek`
[INFO] [stdout]   --> src/sol/q1028.rs:47:8
[INFO] [stdout]    |
[INFO] [stdout] 47 |     fn peek(v: &Vec<Rc<RefCell<TreeNode>>>) -> Rc<RefCell<TreeNode>> {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `parse_next`
[INFO] [stdout]   --> src/sol/q1028.rs:53:8
[INFO] [stdout]    |
[INFO] [stdout] 53 |     fn parse_next(s: &str) -> (Option<Rc<RefCell<TreeNode>>>, usize, &str) {
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `TheDarkKnight`
[INFO] [stdout]  --> src/main.rs:7:8
[INFO] [stdout]   |
[INFO] [stdout] 7 | struct TheDarkKnight;
[INFO] [stdout]   |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `nothing_is_true`
[INFO] [stdout]   --> src/main.rs:10:8
[INFO] [stdout]    |
[INFO] [stdout] 10 |     fn nothing_is_true(self) {}
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 14 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `dep`
[INFO] [stdout]   --> src/sol/q1028.rs:13:20
[INFO] [stdout]    |
[INFO] [stdout] 13 |         let (node, dep, mut remain) = Solution::parse_next(&s);
[INFO] [stdout]    |                    ^^^ help: if this is intentional, prefix it with an underscore: `_dep`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/utils/node.rs:58:13
[INFO] [stdout]    |
[INFO] [stdout] 58 |         let mut node2 = TreeNode::new(6);
[INFO] [stdout]    |             ----^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/utils/node.rs:60:13
[INFO] [stdout]    |
[INFO] [stdout] 60 |         let mut node4 = TreeNode::new(3);
[INFO] [stdout]    |             ----^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/utils/node.rs:61:13
[INFO] [stdout]    |
[INFO] [stdout] 61 |         let mut node5 = TreeNode::new(2);
[INFO] [stdout]    |             ----^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/utils/node.rs:78:13
[INFO] [stdout]    |
[INFO] [stdout] 78 |         let mut node2 = TreeNode::new(6);
[INFO] [stdout]    |             ----^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/utils/node.rs:80:13
[INFO] [stdout]    |
[INFO] [stdout] 80 |         let mut node4 = TreeNode::new(4);
[INFO] [stdout]    |             ----^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/utils/node.rs:81:13
[INFO] [stdout]    |
[INFO] [stdout] 81 |         let mut node5 = TreeNode::new(3);
[INFO] [stdout]    |             ----^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/sol/q1028.rs:32:25
[INFO] [stdout]    |
[INFO] [stdout] 32 |                     let mut cur = Solution::peek(&stack);
[INFO] [stdout]    |                         ----^^^
[INFO] [stdout]    |                         |
[INFO] [stdout]    |                         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `get_single_node`
[INFO] [stdout]   --> src/utils/node.rs:90:8
[INFO] [stdout]    |
[INFO] [stdout] 90 |     fn get_single_node() -> TreeNode {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `test_single_node_tree`
[INFO] [stdout]   --> src/utils/node.rs:94:8
[INFO] [stdout]    |
[INFO] [stdout] 94 |     fn test_single_node_tree() {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `TheDarkKnight`
[INFO] [stdout]  --> src/main.rs:7:8
[INFO] [stdout]   |
[INFO] [stdout] 7 | struct TheDarkKnight;
[INFO] [stdout]   |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `nothing_is_true`
[INFO] [stdout]   --> src/main.rs:10:8
[INFO] [stdout]    |
[INFO] [stdout] 10 |     fn nothing_is_true(self) {}
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 16 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.75s
[INFO] running `Command { std: "docker" "inspect" "508cd2ccb767d67d50845e90bb7b37cb80ad5efad2e1ba01dac7cf4963ac8b5d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "508cd2ccb767d67d50845e90bb7b37cb80ad5efad2e1ba01dac7cf4963ac8b5d", kill_on_drop: false }`
[INFO] [stdout] 508cd2ccb767d67d50845e90bb7b37cb80ad5efad2e1ba01dac7cf4963ac8b5d