[INFO] cloning repository https://github.com/ray33ee/linkedstack
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ray33ee/linkedstack" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fray33ee%2Flinkedstack", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fray33ee%2Flinkedstack'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ccec475fce72c7b3f3753bd6feee663a61f55620
[INFO] checking ray33ee/linkedstack against try#15e8bc6907ab2b3623cb52acc726f4787458df64 for pr-141352
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fray33ee%2Flinkedstack" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ray33ee/linkedstack on toolchain 15e8bc6907ab2b3623cb52acc726f4787458df64
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+15e8bc6907ab2b3623cb52acc726f4787458df64" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ray33ee/linkedstack
[INFO] finished tweaking git repo https://github.com/ray33ee/linkedstack
[INFO] tweaked toml for git repo https://github.com/ray33ee/linkedstack written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/ray33ee/linkedstack 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" "+15e8bc6907ab2b3623cb52acc726f4787458df64" "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]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded tool v0.1.5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/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:eea15d5475069c3ef791f10c2c6b5af2ee421ef2da1e680ecce1cba46243983b" "/opt/rustwide/cargo-home/bin/cargo" "+15e8bc6907ab2b3623cb52acc726f4787458df64" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 58643e6375e7ac56ce7d109540d8586eaa5ca03ab544222d1f705335f2efba12
[INFO] running `Command { std: "docker" "start" "-a" "58643e6375e7ac56ce7d109540d8586eaa5ca03ab544222d1f705335f2efba12", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "58643e6375e7ac56ce7d109540d8586eaa5ca03ab544222d1f705335f2efba12", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "58643e6375e7ac56ce7d109540d8586eaa5ca03ab544222d1f705335f2efba12", kill_on_drop: false }`
[INFO] [stdout] 58643e6375e7ac56ce7d109540d8586eaa5ca03ab544222d1f705335f2efba12
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/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" "RUSTDOCFLAGS=--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:eea15d5475069c3ef791f10c2c6b5af2ee421ef2da1e680ecce1cba46243983b" "/opt/rustwide/cargo-home/bin/cargo" "+15e8bc6907ab2b3623cb52acc726f4787458df64" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 60dd31978b6961962b09ddd90f371656bca7387fad41392056a928eee5a20ef5
[INFO] running `Command { std: "docker" "start" "-a" "60dd31978b6961962b09ddd90f371656bca7387fad41392056a928eee5a20ef5", kill_on_drop: false }`
[INFO] [stderr]     Checking tool v0.1.5
[INFO] [stderr]     Checking linkedstack v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::borrow::Borrow`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::borrow::Borrow`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:97:51
[INFO] [stdout]    |
[INFO] [stdout] 97 |     fn recursive_clone(&self, re: &NodeOption<T>, mut clne: Self) -> Self {
[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/main.rs:97:51
[INFO] [stdout]    |
[INFO] [stdout] 97 |     fn recursive_clone(&self, re: &NodeOption<T>, mut clne: Self) -> Self {
[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: struct `Iter` is never constructed
[INFO] [stdout]   --> src/main.rs:20:8
[INFO] [stdout]    |
[INFO] [stdout] 20 | struct Iter<'a, T> {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `pop` and `len` are never used
[INFO] [stdout]   --> src/main.rs:67:12
[INFO] [stdout]    |
[INFO] [stdout] 42 | / impl<T> LinkedStack<T>
[INFO] [stdout] 43 | |     where T: Display + Clone
[INFO] [stdout]    | |____________________________- methods in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 67 |       pub fn pop(& mut self) -> Result<T, &str> {
[INFO] [stdout]    |              ^^^
[INFO] [stdout] ...
[INFO] [stdout] 80 |       pub fn len(&self) -> usize {
[INFO] [stdout]    |              ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Iter` is never constructed
[INFO] [stdout]   --> src/main.rs:20:8
[INFO] [stdout]    |
[INFO] [stdout] 20 | struct Iter<'a, T> {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `pop` and `len` are never used
[INFO] [stdout]   --> src/main.rs:67:12
[INFO] [stdout]    |
[INFO] [stdout] 42 | / impl<T> LinkedStack<T>
[INFO] [stdout] 43 | |     where T: Display + Clone
[INFO] [stdout]    | |____________________________- methods in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 67 |       pub fn pop(& mut self) -> Result<T, &str> {
[INFO] [stdout]    |              ^^^
[INFO] [stdout] ...
[INFO] [stdout] 80 |       pub fn len(&self) -> usize {
[INFO] [stdout]    |              ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.14s
[INFO] running `Command { std: "docker" "inspect" "60dd31978b6961962b09ddd90f371656bca7387fad41392056a928eee5a20ef5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "60dd31978b6961962b09ddd90f371656bca7387fad41392056a928eee5a20ef5", kill_on_drop: false }`
[INFO] [stdout] 60dd31978b6961962b09ddd90f371656bca7387fad41392056a928eee5a20ef5