[INFO] cloning repository https://github.com/wucheng/leetcode-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/wucheng/leetcode-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fwucheng%2Fleetcode-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fwucheng%2Fleetcode-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 31af7426ee4af600f3c11e98886b3cc44e46af88
[INFO] checking wucheng/leetcode-rust against master#ab26b175979ee7b2cb3302dce204b99df96f7efb for pr-157696
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fwucheng%2Fleetcode-rust" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/wucheng/leetcode-rust
[INFO] finished tweaking git repo https://github.com/wucheng/leetcode-rust
[INFO] tweaked toml for git repo https://github.com/wucheng/leetcode-rust written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/wucheng/leetcode-rust on toolchain ab26b175979ee7b2cb3302dce204b99df96f7efb
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ab26b175979ee7b2cb3302dce204b99df96f7efb" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/wucheng/leetcode-rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ab26b175979ee7b2cb3302dce204b99df96f7efb" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded rand_pcg v0.1.1
[INFO] [stderr]   Downloaded rand_core v0.3.0
[INFO] [stderr]   Downloaded rand_os v0.1.1
[INFO] [stderr]   Downloaded rand v0.6.4
[INFO] [stderr]   Downloaded libc v0.2.47
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,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" "-m" "1610612736" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:3a6becf2bc8dde7f3fa57ede90e4f284e72d296796fc446bbb1e2c7cc0530151" "sleep" "infinity", kill_on_drop: false }`
[INFO] [stdout] f96dbc90c11fd5b5b7c62527ea640faed08072486238bdfbd4660e7e142a5147
[INFO] running `Command { std: "docker" "start" "f96dbc90c11fd5b5b7c62527ea640faed08072486238bdfbd4660e7e142a5147", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-w" "/opt/rustwide/workdir" "--user" "0:0" "f96dbc90c11fd5b5b7c62527ea640faed08072486238bdfbd4660e7e142a5147" "/opt/rustwide/cargo-home/bin/cargo" "+ab26b175979ee7b2cb3302dce204b99df96f7efb" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f96dbc90c11fd5b5b7c62527ea640faed08072486238bdfbd4660e7e142a5147", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-w" "/opt/rustwide/workdir" "--user" "0:0" "f96dbc90c11fd5b5b7c62527ea640faed08072486238bdfbd4660e7e142a5147" "/opt/rustwide/cargo-home/bin/cargo" "+ab26b175979ee7b2cb3302dce204b99df96f7efb" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr]     Checking rand_core v0.3.0
[INFO] [stderr]    Compiling autocfg v0.1.2
[INFO] [stderr]    Compiling libc v0.2.47
[INFO] [stderr]    Compiling rand_pcg v0.1.1
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand v0.6.4
[INFO] [stderr]     Checking rand_xorshift v0.1.1
[INFO] [stderr]     Checking rand_hc v0.1.0
[INFO] [stderr]     Checking rand_isaac v0.1.1
[INFO] [stderr]     Checking rand_os v0.1.1
[INFO] [stderr]     Checking leetcode_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused attribute `warn`
[INFO] [stdout]   --> src/s0617_merge_two_binary_trees/merge_two_binary_trees.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |         #[warn(unreachable_code)]
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] note: the built-in attribute `warn` will be ignored, since it's applied to the macro invocation `unreachable`
[INFO] [stdout]   --> src/s0617_merge_two_binary_trees/merge_two_binary_trees.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |         unreachable!()
[INFO] [stdout]    |         ^^^^^^^^^^^
[INFO] [stdout]    = note: `#[warn(unused_attributes)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused attribute `warn`
[INFO] [stdout]   --> src/s0617_merge_two_binary_trees/merge_two_binary_trees.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |         #[warn(unreachable_code)]
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] note: the built-in attribute `warn` will be ignored, since it's applied to the macro invocation `unreachable`
[INFO] [stdout]   --> src/s0617_merge_two_binary_trees/merge_two_binary_trees.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |         unreachable!()
[INFO] [stdout]    |         ^^^^^^^^^^^
[INFO] [stdout]    = note: `#[warn(unused_attributes)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> src/s0617_merge_two_binary_trees/merge_two_binary_trees.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout]  9 | /         match (t1, t2) {
[INFO] [stdout] 10 | |             (None, None) => return None,
[INFO] [stdout] 11 | |             (Some(t1_rc), None) => return Some(t1_rc.clone()),
[INFO] [stdout] 12 | |             (None, Some(t2_rc)) => return Some(t2_rc.clone()),
[INFO] [stdout] ...  |
[INFO] [stdout] 23 | |         }
[INFO] [stdout]    | |_________- any code following this `match` expression is unreachable, as all arms diverge
[INFO] [stdout] 24 |           #[warn(unreachable_code)]
[INFO] [stdout] 25 |           unreachable!()
[INFO] [stdout]    |           ^^^^^^^^^^^^^^ unreachable expression
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Solution` is never constructed
[INFO] [stdout]  --> src/s0206_reverse_linked_list/reverse_linked_list.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct Solution;
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `reverse_list` is never used
[INFO] [stdout]  --> src/s0206_reverse_linked_list/reverse_linked_list.rs:6:12
[INFO] [stdout]   |
[INFO] [stdout] 5 | impl Solution {
[INFO] [stdout]   | ------------- associated function in this implementation
[INFO] [stdout] 6 |     pub fn reverse_list(head: Option<Box<ListNode>>) -> Option<Box<ListNode>> {
[INFO] [stdout]   |            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Solution` is never constructed
[INFO] [stdout]  --> src/s0617_merge_two_binary_trees/merge_two_binary_trees.rs:6:12
[INFO] [stdout]   |
[INFO] [stdout] 6 | pub struct Solution;
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `merge_trees` is never used
[INFO] [stdout]  --> src/s0617_merge_two_binary_trees/merge_two_binary_trees.rs:8:12
[INFO] [stdout]   |
[INFO] [stdout] 7 | impl Solution {
[INFO] [stdout]   | ------------- associated function in this implementation
[INFO] [stdout] 8 |     pub fn merge_trees(t1: Option<Rc<RefCell<TreeNode>>>, t2: Option<Rc<RefCell<TreeNode>>>) -> Option<Rc<RefCell<TreeNode>>> {
[INFO] [stdout]   |            ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> src/s0617_merge_two_binary_trees/merge_two_binary_trees.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout]  9 | /         match (t1, t2) {
[INFO] [stdout] 10 | |             (None, None) => return None,
[INFO] [stdout] 11 | |             (Some(t1_rc), None) => return Some(t1_rc.clone()),
[INFO] [stdout] 12 | |             (None, Some(t2_rc)) => return Some(t2_rc.clone()),
[INFO] [stdout] ...  |
[INFO] [stdout] 23 | |         }
[INFO] [stdout]    | |_________- any code following this `match` expression is unreachable, as all arms diverge
[INFO] [stdout] 24 |           #[warn(unreachable_code)]
[INFO] [stdout] 25 |           unreachable!()
[INFO] [stdout]    |           ^^^^^^^^^^^^^^ unreachable expression
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/s0206_reverse_linked_list/reverse_linked_list.rs:39:13
[INFO] [stdout]    |
[INFO] [stdout] 39 |         let mut third_node = ListNode::new(3);
[INFO] [stdout]    |             ----^^^^^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.40s
[INFO] running `Command { std: "docker" "inspect" "f96dbc90c11fd5b5b7c62527ea640faed08072486238bdfbd4660e7e142a5147", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f96dbc90c11fd5b5b7c62527ea640faed08072486238bdfbd4660e7e142a5147", kill_on_drop: false }`
[INFO] [stdout] f96dbc90c11fd5b5b7c62527ea640faed08072486238bdfbd4660e7e142a5147
