[INFO] cloning repository https://github.com/jwfy/rust-learn
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jwfy/rust-learn" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjwfy%2Frust-learn", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjwfy%2Frust-learn'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 323f8661e2cc328a424f020132079c17b239b3f9
[INFO] checking jwfy/rust-learn against try#39e1293fce4b650061e85dda88aa428f726a8444 for pr-88041
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjwfy%2Frust-learn" "/workspace/builds/worker-77/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-77/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jwfy/rust-learn on toolchain 39e1293fce4b650061e85dda88aa428f726a8444
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/jwfy/rust-learn
[INFO] finished tweaking git repo https://github.com/jwfy/rust-learn
[INFO] tweaked toml for git repo https://github.com/jwfy/rust-learn written to /workspace/builds/worker-77/source/Cargo.toml
[INFO] crate git repo https://github.com/jwfy/rust-learn already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "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-77/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-77/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" "+39e1293fce4b650061e85dda88aa428f726a8444" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 98ccacf2e14251db874adf29996df47205846a90d72c3f8c8c3fdb842451d4f0
[INFO] running `Command { std: "docker" "start" "-a" "98ccacf2e14251db874adf29996df47205846a90d72c3f8c8c3fdb842451d4f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "98ccacf2e14251db874adf29996df47205846a90d72c3f8c8c3fdb842451d4f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "98ccacf2e14251db874adf29996df47205846a90d72c3f8c8c3fdb842451d4f0", kill_on_drop: false }`
[INFO] [stdout] 98ccacf2e14251db874adf29996df47205846a90d72c3f8c8c3fdb842451d4f0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-77/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-77/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" "+39e1293fce4b650061e85dda88aa428f726a8444" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4307846242ec3a049ae6a83e3ad9088a083ac28b032b2cff23b7c3206166c914
[INFO] running `Command { std: "docker" "start" "-a" "4307846242ec3a049ae6a83e3ad9088a083ac28b032b2cff23b7c3206166c914", kill_on_drop: false }`
[INFO] [stderr]     Checking rust-learn v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field is never read: `id`
[INFO] [stdout]  --> src/threadpool/threadpool.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     id : usize,
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `thread`
[INFO] [stdout]  --> src/threadpool/threadpool.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 |     thread: JoinHandle<()>
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `workers`
[INFO] [stdout]   --> src/threadpool/threadpool.rs:29:5
[INFO] [stdout]    |
[INFO] [stdout] 29 |     workers: Vec<Worker>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `More`
[INFO] [stdout]   --> src/list/first.rs:39:3
[INFO] [stdout]    |
[INFO] [stdout] 39 |   More(Box<Node>),
[INFO] [stdout]    |   ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `iter`
[INFO] [stdout]   --> src/basic/iter.rs:57:13
[INFO] [stdout]    |
[INFO] [stdout] 57 |         let iter = v1.iter();
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_iter`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `iter`
[INFO] [stdout]   --> src/basic/iter.rs:58:13
[INFO] [stdout]    |
[INFO] [stdout] 58 |         let iter = &v1.iter();
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_iter`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `elem`
[INFO] [stdout]   --> src/list/first.rs:43:3
[INFO] [stdout]    |
[INFO] [stdout] 43 |   elem: i32,
[INFO] [stdout]    |   ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> src/list/first.rs:48:10
[INFO] [stdout]    |
[INFO] [stdout] 48 |   pub fn new() -> Self {
[INFO] [stdout]    |          ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `push`
[INFO] [stdout]   --> src/list/first.rs:53:10
[INFO] [stdout]    |
[INFO] [stdout] 53 |   pub fn push(&mut self, elem:i32) {
[INFO] [stdout]    |          ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `pop`
[INFO] [stdout]   --> src/list/first.rs:72:10
[INFO] [stdout]    |
[INFO] [stdout] 72 |   pub fn pop(&mut self) -> Option<i32> {
[INFO] [stdout]    |          ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> src/list/second.rs:30:12
[INFO] [stdout]    |
[INFO] [stdout] 30 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `push`
[INFO] [stdout]   --> src/list/second.rs:37:12
[INFO] [stdout]    |
[INFO] [stdout] 37 |     pub fn push(&mut self, elem: T) {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `peek`
[INFO] [stdout]   --> src/list/second.rs:70:12
[INFO] [stdout]    |
[INFO] [stdout] 70 |     pub fn peek(&self) -> Option<&T> {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `peek_mut`
[INFO] [stdout]   --> src/list/second.rs:81:12
[INFO] [stdout]    |
[INFO] [stdout] 81 |     pub fn peek_mut(&mut self) -> Option<&mut T> {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `into_iter`
[INFO] [stdout]   --> src/list/second.rs:88:12
[INFO] [stdout]    |
[INFO] [stdout] 88 |     pub fn into_iter(self) -> IntoIter<T> {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]  --> src/basic/iter.rs:7:8
[INFO] [stdout]   |
[INFO] [stdout] 7 |     fn new() -> Counter {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `piter`
[INFO] [stdout]   --> src/basic/iter.rs:28:4
[INFO] [stdout]    |
[INFO] [stdout] 28 | fn piter<U, T>(t : T)
[INFO] [stdout]    |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 15 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `id`
[INFO] [stdout]  --> src/threadpool/threadpool.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     id : usize,
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `thread`
[INFO] [stdout]  --> src/threadpool/threadpool.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 |     thread: JoinHandle<()>
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `workers`
[INFO] [stdout]   --> src/threadpool/threadpool.rs:29:5
[INFO] [stdout]    |
[INFO] [stdout] 29 |     workers: Vec<Worker>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `into_iter`
[INFO] [stdout]   --> src/list/second.rs:88:12
[INFO] [stdout]    |
[INFO] [stdout] 88 |     pub fn into_iter(self) -> IntoIter<T> {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.51s
[INFO] running `Command { std: "docker" "inspect" "4307846242ec3a049ae6a83e3ad9088a083ac28b032b2cff23b7c3206166c914", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4307846242ec3a049ae6a83e3ad9088a083ac28b032b2cff23b7c3206166c914", kill_on_drop: false }`
[INFO] [stdout] 4307846242ec3a049ae6a83e3ad9088a083ac28b032b2cff23b7c3206166c914