[INFO] cloning repository https://github.com/tony612/rust-by-example
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tony612/rust-by-example" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftony612%2Frust-by-example", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftony612%2Frust-by-example'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 12770c03945679fc114a5ef5accc51c6ecc0e8f9
[INFO] testing tony612/rust-by-example against master#733b47ea4b1b86216f14ef56e49440c33933f230+rustflags=-Copt-level=3 for pr-138759
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftony612%2Frust-by-example" "/workspace/builds/worker-1-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/tony612/rust-by-example
[INFO] finished tweaking git repo https://github.com/tony612/rust-by-example
[INFO] tweaked toml for git repo https://github.com/tony612/rust-by-example written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/tony612/rust-by-example on toolchain 733b47ea4b1b86216f14ef56e49440c33933f230
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+733b47ea4b1b86216f14ef56e49440c33933f230" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/tony612/rust-by-example 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" "+733b47ea4b1b86216f14ef56e49440c33933f230" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+733b47ea4b1b86216f14ef56e49440c33933f230" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e245f25466b224f4579cbeb969c7d557b4a378af416ed459784d86a1e4f053ea
[INFO] running `Command { std: "docker" "start" "-a" "e245f25466b224f4579cbeb969c7d557b4a378af416ed459784d86a1e4f053ea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e245f25466b224f4579cbeb969c7d557b4a378af416ed459784d86a1e4f053ea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e245f25466b224f4579cbeb969c7d557b4a378af416ed459784d86a1e4f053ea", kill_on_drop: false }`
[INFO] [stdout] e245f25466b224f4579cbeb969c7d557b4a378af416ed459784d86a1e4f053ea
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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 -Copt-level=3" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+733b47ea4b1b86216f14ef56e49440c33933f230" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 490e7bd722522c3489146567060ade8034ee71c78e3842a3f6c15b73b5c82c2f
[INFO] running `Command { std: "docker" "start" "-a" "490e7bd722522c3489146567060ade8034ee71c78e3842a3f6c15b73b5c82c2f", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.95
[INFO] [stderr]    Compiling syn v1.0.72
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]    Compiling anyhow v1.0.40
[INFO] [stderr]    Compiling pin-project-lite v0.2.6
[INFO] [stderr]    Compiling once_cell v1.7.2
[INFO] [stderr]    Compiling instant v0.1.9
[INFO] [stderr]    Compiling tokio v1.6.1
[INFO] [stderr]    Compiling parking_lot_core v0.8.3
[INFO] [stderr]    Compiling mio v0.7.11
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling signal-hook-registry v1.4.0
[INFO] [stderr]    Compiling parking_lot v0.11.1
[INFO] [stderr]    Compiling tokio-macros v1.2.0
[INFO] [stderr]    Compiling rust-by-example v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: function `longest` is never used
[INFO] [stdout]  --> src/lifetime/function.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn longest<'a>(s1: &'a String, s2: &'a String) -> &'a String {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `pick_first` is never used
[INFO] [stdout]   --> src/lifetime/function.rs:18:4
[INFO] [stdout]    |
[INFO] [stdout] 18 | fn pick_first<'a>(s1: &'a String, _s2: &String) -> &'a String {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `MyStruct` is never constructed
[INFO] [stdout]  --> src/lifetime/method.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct MyStruct {}
[INFO] [stdout]   |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `empty` and `msg` are never used
[INFO] [stdout]  --> src/lifetime/method.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | impl MyStruct {
[INFO] [stdout]   | ------------- methods in this implementation
[INFO] [stdout] 4 |     fn empty(&self, _msg: &str) -> &str {
[INFO] [stdout]   |        ^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 8 |     fn msg<'a>(&self, msg: &'a str) -> &'a str {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `MyStruct` is never constructed
[INFO] [stdout]  --> src/lifetime/struct.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct MyStruct<'a> {
[INFO] [stdout]   |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `empty` and `msg` are never used
[INFO] [stdout]   --> src/lifetime/struct.rs:6:8
[INFO] [stdout]    |
[INFO] [stdout] 5  | impl<'a> MyStruct<'a> {
[INFO] [stdout]    | --------------------- methods in this implementation
[INFO] [stdout] 6  |     fn empty(&self, _msg: &str) -> &str {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 10 |     fn msg<'b>(&self, msg: &'b str) -> &'b str {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `hygiene` is never used
[INFO] [stdout]  --> src/macro/hygiene.rs:8:4
[INFO] [stdout]   |
[INFO] [stdout] 8 | fn hygiene() -> usize {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `across_scope` is never used
[INFO] [stdout]   --> src/macro/hygiene.rs:22:4
[INFO] [stdout]    |
[INFO] [stdout] 22 | fn across_scope() -> usize {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `ref_mut` is never used
[INFO] [stdout]  --> src/pattern_match/ref.rs:2:4
[INFO] [stdout]   |
[INFO] [stdout] 2 | fn ref_mut(mut s: Option<&str>) -> Option<&str> {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `ref_mut2` is never used
[INFO] [stdout]   --> src/pattern_match/ref.rs:12:4
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn ref_mut2(mut s: Option<&str>) -> Option<&str> {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `ref_mut3` is never used
[INFO] [stdout]   --> src/pattern_match/ref.rs:20:4
[INFO] [stdout]    |
[INFO] [stdout] 20 | fn ref_mut3(s: Option<&str>) -> Option<&str> {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Foo` is never constructed
[INFO] [stdout]   --> src/pattern_match/ref.rs:31:8
[INFO] [stdout]    |
[INFO] [stdout] 31 | struct Foo {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `and_mut` is never used
[INFO] [stdout]   --> src/pattern_match/ref.rs:35:4
[INFO] [stdout]    |
[INFO] [stdout] 35 | fn and_mut(input: Option<&mut Foo>) -> Option<Foo> {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Cell` is never constructed
[INFO] [stdout]  --> src/pointer/cell.rs:4:12
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub struct Cell<T> {
[INFO] [stdout]   |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `set`, and `get` are never used
[INFO] [stdout]   --> src/pointer/cell.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 11 | impl<T> Cell<T> {
[INFO] [stdout]    | --------------- associated items in this implementation
[INFO] [stdout] 12 |     pub fn new(value: T) -> Cell<T> {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 18 |     pub fn set(&self, val: T) {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 27 |     pub fn get(&self) -> T
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `RcInner` is never constructed
[INFO] [stdout]  --> src/pointer/rc.rs:6:8
[INFO] [stdout]   |
[INFO] [stdout] 6 | struct RcInner<T> {
[INFO] [stdout]   |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Rc` is never constructed
[INFO] [stdout]   --> src/pointer/rc.rs:11:8
[INFO] [stdout]    |
[INFO] [stdout] 11 | struct Rc<T> {
[INFO] [stdout]    |        ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/pointer/rc.rs:17:8
[INFO] [stdout]    |
[INFO] [stdout] 16 | impl<T> Rc<T> {
[INFO] [stdout]    | ------------- associated function in this implementation
[INFO] [stdout] 17 |     fn new(value: T) -> Rc<T> {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `print_ref_copy` is never used
[INFO] [stdout]   --> src/pointer/rc.rs:50:4
[INFO] [stdout]    |
[INFO] [stdout] 50 | fn print_ref_copy<T>(copied_ref: &RcInner<T>) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `RefState` is never used
[INFO] [stdout]  --> src/pointer/refcell.rs:9:6
[INFO] [stdout]   |
[INFO] [stdout] 9 | enum RefState {
[INFO] [stdout]   |      ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `RefCell` is never constructed
[INFO] [stdout]   --> src/pointer/refcell.rs:15:8
[INFO] [stdout]    |
[INFO] [stdout] 15 | struct RefCell<T> {
[INFO] [stdout]    |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `borrow`, and `borrow_mut` are never used
[INFO] [stdout]   --> src/pointer/refcell.rs:21:8
[INFO] [stdout]    |
[INFO] [stdout] 20 | impl<T> RefCell<T> {
[INFO] [stdout]    | ------------------ associated items in this implementation
[INFO] [stdout] 21 |     fn new(value: T) -> RefCell<T> {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] ...
[INFO] [stdout] 28 |     fn borrow(&self) -> Option<Ref<T>>
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 45 |     fn borrow_mut(&self) -> Option<RefMut<T>>
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Ref` is never constructed
[INFO] [stdout]   --> src/pointer/refcell.rs:58:8
[INFO] [stdout]    |
[INFO] [stdout] 58 | struct Ref<'refcell, T> {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `RefMut` is never constructed
[INFO] [stdout]   --> src/pointer/refcell.rs:82:8
[INFO] [stdout]    |
[INFO] [stdout] 82 | struct RefMut<'refcell, T> {
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Sender` is never constructed
[INFO] [stdout]   --> src/sync/mpsc.rs:25:12
[INFO] [stdout]    |
[INFO] [stdout] 25 | pub struct Sender<T> {
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `send` is never used
[INFO] [stdout]   --> src/sync/mpsc.rs:30:8
[INFO] [stdout]    |
[INFO] [stdout] 29 | impl<T> Sender<T> {
[INFO] [stdout]    | ----------------- method in this implementation
[INFO] [stdout] 30 |     fn send(&self, v: T) {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Receiver` is never constructed
[INFO] [stdout]   --> src/sync/mpsc.rs:66:8
[INFO] [stdout]    |
[INFO] [stdout] 66 | struct Receiver<T> {
[INFO] [stdout]    |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `recv` is never used
[INFO] [stdout]   --> src/sync/mpsc.rs:72:8
[INFO] [stdout]    |
[INFO] [stdout] 71 | impl<T> Receiver<T> {
[INFO] [stdout]    | ------------------- method in this implementation
[INFO] [stdout] 72 |     fn recv(&mut self) -> Option<T> {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Inner` is never constructed
[INFO] [stdout]   --> src/sync/mpsc.rs:95:8
[INFO] [stdout]    |
[INFO] [stdout] 95 | struct Inner<T> {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Shared` is never constructed
[INFO] [stdout]    --> src/sync/mpsc.rs:100:8
[INFO] [stdout]     |
[INFO] [stdout] 100 | struct Shared<T> {
[INFO] [stdout]     |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `channel` is never used
[INFO] [stdout]    --> src/sync/mpsc.rs:105:4
[INFO] [stdout]     |
[INFO] [stdout] 105 | fn channel<T>() -> (Sender<T>, Receiver<T>) {
[INFO] [stdout]     |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Actor` is never used
[INFO] [stdout]  --> src/tokio/actor.rs:5:11
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub trait Actor {
[INFO] [stdout]   |           ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `ActorMessage` is never constructed
[INFO] [stdout]   --> src/tokio/actor.rs:11:12
[INFO] [stdout]    |
[INFO] [stdout] 11 | pub struct ActorMessage<Request, Reply> {
[INFO] [stdout]    |            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `spawn` is never used
[INFO] [stdout]   --> src/tokio/actor.rs:16:8
[INFO] [stdout]    |
[INFO] [stdout] 16 | pub fn spawn<A: Actor>(mut actor: A, mailbox: usize) -> Pid<A::Request, A::Reply>
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Pid` is never constructed
[INFO] [stdout]   --> src/tokio/actor.rs:36:12
[INFO] [stdout]    |
[INFO] [stdout] 36 | pub struct Pid<Request, Reply> {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `send` is never used
[INFO] [stdout]   --> src/tokio/actor.rs:41:18
[INFO] [stdout]    |
[INFO] [stdout] 40 | impl<Request, Reply> Pid<Request, Reply> {
[INFO] [stdout]    | ---------------------------------------- method in this implementation
[INFO] [stdout] 41 |     pub async fn send(&self, data: Request) -> Result<Reply> {
[INFO] [stdout]    |                  ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `watch` is never used
[INFO] [stdout]  --> src/tokio/watch.rs:4:10
[INFO] [stdout]   |
[INFO] [stdout] 4 | async fn watch() -> Result<()> {
[INFO] [stdout]   |          ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: calls to `std::mem::drop` with a reference instead of an owned value does nothing
[INFO] [stdout]   --> src/pointer/rc.rs:66:13
[INFO] [stdout]    |
[INFO] [stdout] 66 |             drop(inner);
[INFO] [stdout]    |             ^^^^^-----^
[INFO] [stdout]    |                  |
[INFO] [stdout]    |                  argument has type `&RcInner<T>`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dropping_references)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the expression or result
[INFO] [stdout]    |
[INFO] [stdout] 66 -             drop(inner);
[INFO] [stdout] 66 +             let _ = inner;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Box::<T>::from_raw` that must be used
[INFO] [stdout]   --> src/pointer/rc.rs:76:26
[INFO] [stdout]    |
[INFO] [stdout] 76 |                 unsafe { Box::from_raw(self.inner.as_ptr()) };
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: call `drop(Box::from_raw(ptr))` if you intend to drop the `Box`
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 76 |                 unsafe { let _ = Box::from_raw(self.inner.as_ptr()); };
[INFO] [stdout]    |                          +++++++                                   +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]   --> src/pointer/refcell.rs:28:15
[INFO] [stdout]    |
[INFO] [stdout] 28 |     fn borrow(&self) -> Option<Ref<T>>
[INFO] [stdout]    |               ^^^^^            ------ the lifetime gets resolved as `'_`
[INFO] [stdout]    |               |
[INFO] [stdout]    |               this lifetime flows to the output
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]    |
[INFO] [stdout] 28 |     fn borrow(&self) -> Option<Ref<'_, T>>
[INFO] [stdout]    |                                    +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]   --> src/pointer/refcell.rs:45:19
[INFO] [stdout]    |
[INFO] [stdout] 45 |     fn borrow_mut(&self) -> Option<RefMut<T>>
[INFO] [stdout]    |                   ^^^^^            --------- the lifetime gets resolved as `'_`
[INFO] [stdout]    |                   |
[INFO] [stdout]    |                   this lifetime flows to the output
[INFO] [stdout]    |
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]    |
[INFO] [stdout] 45 |     fn borrow_mut(&self) -> Option<RefMut<'_, T>>
[INFO] [stdout]    |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 40.75s
[INFO] running `Command { std: "docker" "inspect" "490e7bd722522c3489146567060ade8034ee71c78e3842a3f6c15b73b5c82c2f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "490e7bd722522c3489146567060ade8034ee71c78e3842a3f6c15b73b5c82c2f", kill_on_drop: false }`
[INFO] [stdout] 490e7bd722522c3489146567060ade8034ee71c78e3842a3f6c15b73b5c82c2f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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 -Copt-level=3" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+733b47ea4b1b86216f14ef56e49440c33933f230" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4ee5fdef07db9f974b4af378a1a6f5f59d92451126c582e3c8f3f83eae94edf4
[INFO] running `Command { std: "docker" "start" "-a" "4ee5fdef07db9f974b4af378a1a6f5f59d92451126c582e3c8f3f83eae94edf4", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust-by-example v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: calls to `std::mem::drop` with a reference instead of an owned value does nothing
[INFO] [stdout]   --> src/pointer/rc.rs:66:13
[INFO] [stdout]    |
[INFO] [stdout] 66 |             drop(inner);
[INFO] [stdout]    |             ^^^^^-----^
[INFO] [stdout]    |                  |
[INFO] [stdout]    |                  argument has type `&RcInner<T>`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dropping_references)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the expression or result
[INFO] [stdout]    |
[INFO] [stdout] 66 -             drop(inner);
[INFO] [stdout] 66 +             let _ = inner;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Box::<T>::from_raw` that must be used
[INFO] [stdout]   --> src/pointer/rc.rs:76:26
[INFO] [stdout]    |
[INFO] [stdout] 76 |                 unsafe { Box::from_raw(self.inner.as_ptr()) };
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: call `drop(Box::from_raw(ptr))` if you intend to drop the `Box`
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 76 |                 unsafe { let _ = Box::from_raw(self.inner.as_ptr()); };
[INFO] [stdout]    |                          +++++++                                   +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]   --> src/pointer/refcell.rs:28:15
[INFO] [stdout]    |
[INFO] [stdout] 28 |     fn borrow(&self) -> Option<Ref<T>>
[INFO] [stdout]    |               ^^^^^            ------ the lifetime gets resolved as `'_`
[INFO] [stdout]    |               |
[INFO] [stdout]    |               this lifetime flows to the output
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]    |
[INFO] [stdout] 28 |     fn borrow(&self) -> Option<Ref<'_, T>>
[INFO] [stdout]    |                                    +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stdout]   --> src/pointer/refcell.rs:45:19
[INFO] [stdout]    |
[INFO] [stdout] 45 |     fn borrow_mut(&self) -> Option<RefMut<T>>
[INFO] [stdout]    |                   ^^^^^            --------- the lifetime gets resolved as `'_`
[INFO] [stdout]    |                   |
[INFO] [stdout]    |                   this lifetime flows to the output
[INFO] [stdout]    |
[INFO] [stdout] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stdout]    |
[INFO] [stdout] 45 |     fn borrow_mut(&self) -> Option<RefMut<'_, T>>
[INFO] [stdout]    |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 3.29s
[INFO] running `Command { std: "docker" "inspect" "4ee5fdef07db9f974b4af378a1a6f5f59d92451126c582e3c8f3f83eae94edf4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4ee5fdef07db9f974b4af378a1a6f5f59d92451126c582e3c8f3f83eae94edf4", kill_on_drop: false }`
[INFO] [stdout] 4ee5fdef07db9f974b4af378a1a6f5f59d92451126c582e3c8f3f83eae94edf4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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 -Copt-level=3" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+733b47ea4b1b86216f14ef56e49440c33933f230" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 0dc8c165f0d53c3beaefd18c055ec857e4c1cf69e1221ba6e23bbcf9e42db894
[INFO] running `Command { std: "docker" "start" "-a" "0dc8c165f0d53c3beaefd18c055ec857e4c1cf69e1221ba6e23bbcf9e42db894", kill_on_drop: false }`
[INFO] [stderr] warning: calls to `std::mem::drop` with a reference instead of an owned value does nothing
[INFO] [stderr]   --> src/pointer/rc.rs:66:13
[INFO] [stderr]    |
[INFO] [stderr] 66 |             drop(inner);
[INFO] [stderr]    |             ^^^^^-----^
[INFO] [stderr]    |                  |
[INFO] [stderr]    |                  argument has type `&RcInner<T>`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dropping_references)]` on by default
[INFO] [stderr] help: use `let _ = ...` to ignore the expression or result
[INFO] [stderr]    |
[INFO] [stderr] 66 -             drop(inner);
[INFO] [stderr] 66 +             let _ = inner;
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: unused return value of `Box::<T>::from_raw` that must be used
[INFO] [stderr]   --> src/pointer/rc.rs:76:26
[INFO] [stderr]    |
[INFO] [stderr] 76 |                 unsafe { Box::from_raw(self.inner.as_ptr()) };
[INFO] [stderr]    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: call `drop(Box::from_raw(ptr))` if you intend to drop the `Box`
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]    |
[INFO] [stderr] 76 |                 unsafe { let _ = Box::from_raw(self.inner.as_ptr()); };
[INFO] [stderr]    |                          +++++++                                   +
[INFO] [stderr] 
[INFO] [stderr] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stderr]   --> src/pointer/refcell.rs:28:15
[INFO] [stderr]    |
[INFO] [stderr] 28 |     fn borrow(&self) -> Option<Ref<T>>
[INFO] [stderr]    |               ^^^^^            ------ the lifetime gets resolved as `'_`
[INFO] [stderr]    |               |
[INFO] [stderr]    |               this lifetime flows to the output
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stderr] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stderr]    |
[INFO] [stderr] 28 |     fn borrow(&self) -> Option<Ref<'_, T>>
[INFO] [stderr]    |                                    +++
[INFO] [stderr] 
[INFO] [stderr] warning: lifetime flowing from input to output with different syntax can be confusing
[INFO] [stderr]   --> src/pointer/refcell.rs:45:19
[INFO] [stderr]    |
[INFO] [stderr] 45 |     fn borrow_mut(&self) -> Option<RefMut<T>>
[INFO] [stderr]    |                   ^^^^^            --------- the lifetime gets resolved as `'_`
[INFO] [stderr]    |                   |
[INFO] [stderr]    |                   this lifetime flows to the output
[INFO] [stderr]    |
[INFO] [stderr] help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
[INFO] [stderr]    |
[INFO] [stderr] 45 |     fn borrow_mut(&self) -> Option<RefMut<'_, T>>
[INFO] [stderr]    |                                           +++
[INFO] [stderr] 
[INFO] [stderr] warning: `rust-by-example` (bin "rust-by-example" test) generated 4 warnings
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.05s
[INFO] [stderr]      Running unittests src/main.rs (/opt/rustwide/target/debug/deps/rust_by_example-4df2eefcf5e02643)
[INFO] [stdout] 
[INFO] [stdout] running 31 tests
[INFO] [stdout] test lifetime::function::tests::test_invalid ... ok
[INFO] [stdout] test lifetime::function::tests::test_valid ... ok
[INFO] [stdout] test lifetime::method::tests::test_self_lifetime ... ok
[INFO] [stdout] test pattern_match::r#ref::it_works ... ok
[INFO] [stdout] test pointer::refcell::test::borrow_after_mut ... ok
[INFO] [stdout] test pattern_match::r#ref::it_works2 ... ok
[INFO] [stdout] test pointer::refcell::test::mut_after_borrow ... ok
[INFO] [stdout] test pointer::refcell::test::mut_after_borrow_drop ... ok
[INFO] [stdout] test lifetime::r#struct::tests::test_lifetime ... ok
[INFO] [stdout] test lifetime::function::tests::test_partial_mark ... ok
[INFO] [stdout] test pointer::refcell::test::mut_after_one_borrow_drop ... ok
[INFO] [stdout] test r#macro::hygiene::test_across_scope ... ok
[INFO] [stdout] test r#macro::hygiene::test_hygiene ... ok
[INFO] [stdout] test r#macro::vec::test_empty ... ok
[INFO] [stdout] test r#macro::vec::test_multiple ... ok
[INFO] [stdout] test r#macro::vec::test_repeat ... ok
[INFO] [stdout] test r#macro::vec::test_repeat_non_literal ... ok
[INFO] [stdout] test r#macro::vec::test_tailing ... ok
[INFO] [stdout] test sync::mpsc::test::rx_close ... ok
[INFO] [stdout] test sync::mpsc::test::tx_close ... ok
[INFO] [stdout] test tokio::watch::test_watch ... ok
[INFO] [stdout] test sync::mpsc::test::works ... ok
[INFO] [stdout] test tokio::actor::tests::it_works ... ok
[INFO] [stdout] test lifetime::method::tests::test_other_lifetime ... ok
[INFO] [stdout] test pointer::cell::test::works ... ok
[INFO] [stdout] test pointer::rc::test::clone ... ok
[INFO] [stderr] tcache_thread_shutdown(): unaligned tcache chunk detected
[INFO] [stderr] error: test failed, to rerun pass `--bin rust-by-example`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/target/debug/deps/rust_by_example-4df2eefcf5e02643` (signal: 6, SIGABRT: process abort signal)
[INFO] running `Command { std: "docker" "inspect" "0dc8c165f0d53c3beaefd18c055ec857e4c1cf69e1221ba6e23bbcf9e42db894", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0dc8c165f0d53c3beaefd18c055ec857e4c1cf69e1221ba6e23bbcf9e42db894", kill_on_drop: false }`
[INFO] [stdout] 0dc8c165f0d53c3beaefd18c055ec857e4c1cf69e1221ba6e23bbcf9e42db894
