[INFO] fetching crate closure_with_lee_study 0.1.0...
[INFO] checking closure_with_lee_study-0.1.0 against try#0611f7de057c584b8771102fde7aed6c70c71d3b for pr-146440
[INFO] extracting crate closure_with_lee_study 0.1.0 into /workspace/builds/worker-5-tc2/source
[INFO] started tweaking crates.io crate closure_with_lee_study 0.1.0
[INFO] finished tweaking crates.io crate closure_with_lee_study 0.1.0
[INFO] tweaked toml for crates.io crate closure_with_lee_study 0.1.0 written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate closure_with_lee_study 0.1.0 on toolchain 0611f7de057c584b8771102fde7aed6c70c71d3b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+0611f7de057c584b8771102fde7aed6c70c71d3b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate closure_with_lee_study 0.1.0 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" "+0611f7de057c584b8771102fde7aed6c70c71d3b" "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-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+0611f7de057c584b8771102fde7aed6c70c71d3b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7679b203002a79cda19af2cda906099284c0914c5cfbd1675bc5f6e7c1f40786
[INFO] running `Command { std: "docker" "start" "-a" "7679b203002a79cda19af2cda906099284c0914c5cfbd1675bc5f6e7c1f40786", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7679b203002a79cda19af2cda906099284c0914c5cfbd1675bc5f6e7c1f40786", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7679b203002a79cda19af2cda906099284c0914c5cfbd1675bc5f6e7c1f40786", kill_on_drop: false }`
[INFO] [stdout] 7679b203002a79cda19af2cda906099284c0914c5cfbd1675bc5f6e7c1f40786
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+0611f7de057c584b8771102fde7aed6c70c71d3b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] cf34df3114319c3d2022af69a1ab392db9f295df3a505ef28844afb9e0d4f77f
[INFO] running `Command { std: "docker" "start" "-a" "cf34df3114319c3d2022af69a1ab392db9f295df3a505ef28844afb9e0d4f77f", kill_on_drop: false }`
[INFO] [stderr]     Checking closure_with_lee_study v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: struct `Counter` is never constructed
[INFO] [stdout]   --> src/lib.rs:35:12
[INFO] [stdout]    |
[INFO] [stdout] 35 | pub struct Counter {
[INFO] [stdout]    |            ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `pub` struct has private fields, no public constructor, and is not otherwise reachable through the external API, so consider providing a public constructor or removing it
[INFO] [stdout]    = note: `#[deny(unused_unconstructable_pub_struct)]` (part of `#[deny(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/lib.rs:39:8
[INFO] [stdout]    |
[INFO] [stdout] 38 | impl Counter {
[INFO] [stdout]    | ------------ associated function in this implementation
[INFO] [stdout] 39 |     fn new() -> Counter {
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `closure_with_lee_study` (lib) due to 1 previous error; 1 warning emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unused variable: `v2`
[INFO] [stdout]   --> src/lib.rs:70:13
[INFO] [stdout]    |
[INFO] [stdout] 70 |         let v2: Vec<_> = v1_iter.map(|x| x + 1).collect();
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_v2`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lib.rs:94:13
[INFO] [stdout]    |
[INFO] [stdout] 94 |         let mut counter = Counter::new();
[INFO] [stdout]    |             ----^^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `counter`
[INFO] [stdout]   --> src/lib.rs:94:13
[INFO] [stdout]    |
[INFO] [stdout] 94 |         let mut counter = Counter::new();
[INFO] [stdout]    |             ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_counter`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "cf34df3114319c3d2022af69a1ab392db9f295df3a505ef28844afb9e0d4f77f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cf34df3114319c3d2022af69a1ab392db9f295df3a505ef28844afb9e0d4f77f", kill_on_drop: false }`
[INFO] [stdout] cf34df3114319c3d2022af69a1ab392db9f295df3a505ef28844afb9e0d4f77f
