[INFO] cloning repository https://github.com/vurtnr/concurrency
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/vurtnr/concurrency" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvurtnr%2Fconcurrency", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvurtnr%2Fconcurrency'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0ccca16592d5eb8bc4af6f16c6863632262a833c
[INFO] checking vurtnr/concurrency against try#54cf65b8d066c082e536455049b95943cf30378f for pr-151920
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvurtnr%2Fconcurrency" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/vurtnr/concurrency
[INFO] finished tweaking git repo https://github.com/vurtnr/concurrency
[INFO] tweaked toml for git repo https://github.com/vurtnr/concurrency written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/vurtnr/concurrency on toolchain 54cf65b8d066c082e536455049b95943cf30378f
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+54cf65b8d066c082e536455049b95943cf30378f" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/vurtnr/concurrency 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" "+54cf65b8d066c082e536455049b95943cf30378f" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded oneshot v0.1.6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:61361fe0aef631f17e9d025a70c5a647956f8c671dd02950a60ad3f5cc5526d7" "/opt/rustwide/cargo-home/bin/cargo" "+54cf65b8d066c082e536455049b95943cf30378f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6d5576fe11613ee3b9e2b5743eba2f924e1bc2a0068cbf11a8680cf417a23bdc
[INFO] running `Command { std: "docker" "start" "-a" "6d5576fe11613ee3b9e2b5743eba2f924e1bc2a0068cbf11a8680cf417a23bdc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6d5576fe11613ee3b9e2b5743eba2f924e1bc2a0068cbf11a8680cf417a23bdc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6d5576fe11613ee3b9e2b5743eba2f924e1bc2a0068cbf11a8680cf417a23bdc", kill_on_drop: false }`
[INFO] [stdout] 6d5576fe11613ee3b9e2b5743eba2f924e1bc2a0068cbf11a8680cf417a23bdc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:61361fe0aef631f17e9d025a70c5a647956f8c671dd02950a60ad3f5cc5526d7" "/opt/rustwide/cargo-home/bin/cargo" "+54cf65b8d066c082e536455049b95943cf30378f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3dc77285f56c8716d862f2e024aa0c103bec020a5e986e1915be9f20e623a3cc
[INFO] running `Command { std: "docker" "start" "-a" "3dc77285f56c8716d862f2e024aa0c103bec020a5e986e1915be9f20e623a3cc", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.155
[INFO] [stderr]     Checking hashbrown v0.14.5
[INFO] [stderr]     Checking oneshot v0.1.6
[INFO] [stderr]    Compiling lock_api v0.4.12
[INFO] [stderr]     Checking getrandom v0.2.15
[INFO] [stderr]     Checking parking_lot_core v0.9.10
[INFO] [stderr]     Checking rand_core v0.6.4
[INFO] [stderr]     Checking dashmap v5.5.3
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking concurrency v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `core::task`
[INFO] [stdout]  --> examples/metrics.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use core::task;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `random`
[INFO] [stdout]  --> examples/metrics.rs:4:12
[INFO] [stdout]   |
[INFO] [stdout] 4 | use rand::{random, thread_rng, Rng};
[INFO] [stdout]   |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> examples/metrics.rs:26:5
[INFO] [stdout]    |
[INFO] [stdout] 21 | /     loop {
[INFO] [stdout] 22 | |         thread::sleep(Duration::from_secs(2));
[INFO] [stdout] 23 | |         println!("{}", metrics);
[INFO] [stdout] 24 | |     }
[INFO] [stdout]    | |_____- any code following this expression is unreachable
[INFO] [stdout] 25 |
[INFO] [stdout] 26 |       Ok(())
[INFO] [stdout]    |       ^^^^^^ unreachable expression
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `idx`
[INFO] [stdout]   --> examples/metrics.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     for idx in 0..M {
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_idx`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.53s
[INFO] running `Command { std: "docker" "inspect" "3dc77285f56c8716d862f2e024aa0c103bec020a5e986e1915be9f20e623a3cc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3dc77285f56c8716d862f2e024aa0c103bec020a5e986e1915be9f20e623a3cc", kill_on_drop: false }`
[INFO] [stdout] 3dc77285f56c8716d862f2e024aa0c103bec020a5e986e1915be9f20e623a3cc