[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] checking tony612/rust-by-example against master#5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f for pr-87248
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftony612%2Frust-by-example" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tony612/rust-by-example on toolchain 5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[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-2/source/Cargo.toml
[INFO] crate git repo https://github.com/tony612/rust-by-example already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 35a558494426276514687606afb44fa3b971794898f3d032347343437af18c9d
[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" "35a558494426276514687606afb44fa3b971794898f3d032347343437af18c9d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "35a558494426276514687606afb44fa3b971794898f3d032347343437af18c9d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "35a558494426276514687606afb44fa3b971794898f3d032347343437af18c9d", kill_on_drop: false }`
[INFO] [stdout] 35a558494426276514687606afb44fa3b971794898f3d032347343437af18c9d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 22d3a89da60f41b964a521899047ac233a25d5d5b6181487b92fa3b25059df8d
[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" "22d3a89da60f41b964a521899047ac233a25d5d5b6181487b92fa3b25059df8d", kill_on_drop: false }`
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]    Compiling anyhow v1.0.40
[INFO] [stderr]     Checking pin-project-lite v0.2.6
[INFO] [stderr]     Checking bytes v1.0.1
[INFO] [stderr]    Compiling tokio v1.6.1
[INFO] [stderr]     Checking parking_lot_core v0.8.3
[INFO] [stderr]     Checking signal-hook-registry v1.4.0
[INFO] [stderr]     Checking lock_api v0.4.4
[INFO] [stderr]    Compiling proc-macro2 v1.0.27
[INFO] [stderr]     Checking parking_lot v0.11.1
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking mio v0.7.11
[INFO] [stderr]    Compiling syn v1.0.72
[INFO] [stderr]    Compiling tokio-macros v1.2.0
[INFO] [stderr]     Checking rust-by-example v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: function is never used: `longest`
[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 is never used: `pick_first`
[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 is never constructed: `MyStruct`
[INFO] [stdout]  --> src/lifetime/method.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct MyStruct {}
[INFO] [stdout]   |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `empty`
[INFO] [stdout]  --> src/lifetime/method.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 |     fn empty(&self, _msg: &str) -> &str {
[INFO] [stdout]   |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `msg`
[INFO] [stdout]  --> src/lifetime/method.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 8 |     fn msg<'a>(&self, msg: &'a str) -> &'a str {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `MyStruct`
[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: associated function is never used: `empty`
[INFO] [stdout]  --> src/lifetime/struct.rs:6:8
[INFO] [stdout]   |
[INFO] [stdout] 6 |     fn empty(&self, _msg: &str) -> &str {
[INFO] [stdout]   |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `msg`
[INFO] [stdout]   --> src/lifetime/struct.rs:10:8
[INFO] [stdout]    |
[INFO] [stdout] 10 |     fn msg<'b>(&self, msg: &'b str) -> &'b str {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `hygiene`
[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 is never used: `across_scope`
[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 is never used: `ref_mut`
[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 is never used: `ref_mut2`
[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 is never used: `ref_mut3`
[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: function is never used: `and_mut`
[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: associated function is never used: `new`
[INFO] [stdout]   --> src/pointer/cell.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 12 |     pub fn new(value: T) -> Cell<T> {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> src/pointer/rc.rs:17:8
[INFO] [stdout]    |
[INFO] [stdout] 17 |     fn new(value: T) -> Rc<T> {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Shared`
[INFO] [stdout]   --> src/pointer/refcell.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 11 |     Shared(usize),
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Exclusive`
[INFO] [stdout]   --> src/pointer/refcell.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     Exclusive,
[INFO] [stdout]    |     ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> src/pointer/refcell.rs:21:8
[INFO] [stdout]    |
[INFO] [stdout] 21 |     fn new(value: T) -> RefCell<T> {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `borrow`
[INFO] [stdout]   --> src/pointer/refcell.rs:28:8
[INFO] [stdout]    |
[INFO] [stdout] 28 |     fn borrow(&self) -> Option<Ref<T>>
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `borrow_mut`
[INFO] [stdout]   --> src/pointer/refcell.rs:45:8
[INFO] [stdout]    |
[INFO] [stdout] 45 |     fn borrow_mut(&self) -> Option<RefMut<T>>
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `send`
[INFO] [stdout]   --> src/sync/mpsc.rs:30:8
[INFO] [stdout]    |
[INFO] [stdout] 30 |     fn send(&self, v: T) {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Receiver`
[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: associated function is never used: `recv`
[INFO] [stdout]   --> src/sync/mpsc.rs:72:8
[INFO] [stdout]    |
[INFO] [stdout] 72 |     fn recv(&mut self) -> Option<T> {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `queue`
[INFO] [stdout]   --> src/sync/mpsc.rs:96:5
[INFO] [stdout]    |
[INFO] [stdout] 96 |     queue: VecDeque<T>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `channel`
[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: field is never read: `data`
[INFO] [stdout]   --> src/tokio/actor.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     data: Request,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `sender`
[INFO] [stdout]   --> src/tokio/actor.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     sender: oneshot::Sender<Reply>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `spawn`
[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: associated function is never used: `send`
[INFO] [stdout]   --> src/tokio/actor.rs:41:18
[INFO] [stdout]    |
[INFO] [stdout] 41 |     pub async fn send(&self, data: Request) -> Result<Reply> {
[INFO] [stdout]    |                  ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `watch`
[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: 31 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 28.30s
[INFO] running `Command { std: "docker" "inspect" "22d3a89da60f41b964a521899047ac233a25d5d5b6181487b92fa3b25059df8d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "22d3a89da60f41b964a521899047ac233a25d5d5b6181487b92fa3b25059df8d", kill_on_drop: false }`
[INFO] [stdout] 22d3a89da60f41b964a521899047ac233a25d5d5b6181487b92fa3b25059df8d