[INFO] updating cached repository https://github.com/wucheng/leetcode-rust
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/mnt/big/crater/work/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] 31af7426ee4af600f3c11e98886b3cc44e46af88
[INFO] checking wucheng/leetcode-rust against master#c9edc02e8320a9e5799d185910ece7d491f524e6 for pr-64398
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fwucheng%2Fleetcode-rust" "work/builds/worker-1/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/wucheng/leetcode-rust on toolchain c9edc02e8320a9e5799d185910ece7d491f524e6-alt
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[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 work/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/wucheng/leetcode-rust already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/mnt/big/crater/work/builds/worker-1/source:/opt/rustwide/workdir:ro,Z" "-v" "/mnt/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-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" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 99228ff142117c94f18fd1aca45a30c255aabc802d8ae374d348909ee2214264
[INFO] running `"docker" "start" "-a" "99228ff142117c94f18fd1aca45a30c255aabc802d8ae374d348909ee2214264"`
[INFO] [stderr]     Checking leetcode_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unreachable expression
[INFO] [stderr]   --> src/s0617_merge_two_binary_trees/merge_two_binary_trees.rs:25:9
[INFO] [stderr]    |
[INFO] [stderr] 25 |         unreachable!()
[INFO] [stderr]    |         ^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stderr]    = note: this warning originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unreachable expression
[INFO] [stderr]   --> src/s0617_merge_two_binary_trees/merge_two_binary_trees.rs:25:9
[INFO] [stderr]    |
[INFO] [stderr] 25 |         unreachable!()
[INFO] [stderr]    |         ^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stderr]    = note: this warning originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Solution`
[INFO] [stderr]  --> src/s0206_reverse_linked_list/reverse_linked_list.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub struct Solution;
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `reverse_list`
[INFO] [stderr]  --> src/s0206_reverse_linked_list/reverse_linked_list.rs:6:5
[INFO] [stderr]   |
[INFO] [stderr] 6 |     pub fn reverse_list(head: Option<Box<ListNode>>) -> Option<Box<ListNode>> {
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Solution`
[INFO] [stderr]  --> src/s0617_merge_two_binary_trees/merge_two_binary_trees.rs:6:1
[INFO] [stderr]   |
[INFO] [stderr] 6 | pub struct Solution;
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `merge_trees`
[INFO] [stderr]  --> src/s0617_merge_two_binary_trees/merge_two_binary_trees.rs:8:5
[INFO] [stderr]   |
[INFO] [stderr] 8 |     pub fn merge_trees(t1: Option<Rc<RefCell<TreeNode>>>, t2: Option<Rc<RefCell<TreeNode>>>) -> Option<Rc<RefCell<TreeNode>>> {
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/s0206_reverse_linked_list/reverse_linked_list.rs:39:13
[INFO] [stderr]    |
[INFO] [stderr] 39 |         let mut third_node = ListNode::new(3);
[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]     Finished dev [unoptimized + debuginfo] target(s) in 0.69s
[INFO] running `"docker" "inspect" "99228ff142117c94f18fd1aca45a30c255aabc802d8ae374d348909ee2214264"`
[INFO] running `"docker" "rm" "-f" "99228ff142117c94f18fd1aca45a30c255aabc802d8ae374d348909ee2214264"`
[INFO] [stdout] 99228ff142117c94f18fd1aca45a30c255aabc802d8ae374d348909ee2214264