[INFO] cloning repository https://github.com/halfzebra/rust-smart-pointers-examples
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/halfzebra/rust-smart-pointers-examples" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhalfzebra%2Frust-smart-pointers-examples", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhalfzebra%2Frust-smart-pointers-examples'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d0f57ba42e7466e89ac79f06a9ce5a0f97765967
[INFO] checking halfzebra/rust-smart-pointers-examples against master#936f2600b6c903b04387f74ed5cbce88bb06d243 for pr-91141
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhalfzebra%2Frust-smart-pointers-examples" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/halfzebra/rust-smart-pointers-examples on toolchain 936f2600b6c903b04387f74ed5cbce88bb06d243
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/halfzebra/rust-smart-pointers-examples
[INFO] finished tweaking git repo https://github.com/halfzebra/rust-smart-pointers-examples
[INFO] tweaked toml for git repo https://github.com/halfzebra/rust-smart-pointers-examples written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/halfzebra/rust-smart-pointers-examples already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2e4b2b2a511620b9d4d25b4a1b4418c62697087c52c6e07cbee7fa03039392c8
[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" "2e4b2b2a511620b9d4d25b4a1b4418c62697087c52c6e07cbee7fa03039392c8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2e4b2b2a511620b9d4d25b4a1b4418c62697087c52c6e07cbee7fa03039392c8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2e4b2b2a511620b9d4d25b4a1b4418c62697087c52c6e07cbee7fa03039392c8", kill_on_drop: false }`
[INFO] [stdout] 2e4b2b2a511620b9d4d25b4a1b4418c62697087c52c6e07cbee7fa03039392c8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 26e0a6e35cbde8b11bd84cdcc94fde103c310541fba4ac5cb6857db6d314fcf0
[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" "26e0a6e35cbde8b11bd84cdcc94fde103c310541fba4ac5cb6857db6d314fcf0", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking rust-smart-pointers-examples v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field is never read: `messenger`
[INFO] [stdout]  --> src/limit_tracker.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 |     messenger: &'a T,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `value`
[INFO] [stdout]  --> src/limit_tracker.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     value: usize,
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `max`
[INFO] [stdout]  --> src/limit_tracker.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 |     max: usize,
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> src/limit_tracker.rs:14:12
[INFO] [stdout]    |
[INFO] [stdout] 14 |     pub fn new(messenger: &T, max: usize) -> LimitTracker<T> {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `set_value`
[INFO] [stdout]   --> src/limit_tracker.rs:22:12
[INFO] [stdout]    |
[INFO] [stdout] 22 |     pub fn set_value(&mut self, value: usize) {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/limit_tracker.rs:62:13
[INFO] [stdout]    |
[INFO] [stdout] 62 |             &self.sent_messages.borrow_mut().push(String::from(message));
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 62 |             let _ = &self.sent_messages.borrow_mut().push(String::from(message));
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `value`
[INFO] [stdout]  --> src/reference_cycle_tree.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     value: i32,
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `children`
[INFO] [stdout]  --> src/reference_cycle_tree.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 |     children: RefCell<Vec<Rc<Node>>>,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `value`
[INFO] [stdout]   --> src/main.rs:33:5
[INFO] [stdout]    |
[INFO] [stdout] 33 |     value: T,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `value`
[INFO] [stdout]  --> src/reference_cycle_tree.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     value: i32,
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `children`
[INFO] [stdout]  --> src/reference_cycle_tree.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 |     children: RefCell<Vec<Rc<Node>>>,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `value`
[INFO] [stdout]   --> src/main.rs:33:5
[INFO] [stdout]    |
[INFO] [stdout] 33 |     value: T,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.95s
[INFO] running `Command { std: "docker" "inspect" "26e0a6e35cbde8b11bd84cdcc94fde103c310541fba4ac5cb6857db6d314fcf0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "26e0a6e35cbde8b11bd84cdcc94fde103c310541fba4ac5cb6857db6d314fcf0", kill_on_drop: false }`
[INFO] [stdout] 26e0a6e35cbde8b11bd84cdcc94fde103c310541fba4ac5cb6857db6d314fcf0