[INFO] cloning repository https://github.com/sinagajunior/rust-concurency
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/sinagajunior/rust-concurency" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsinagajunior%2Frust-concurency", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsinagajunior%2Frust-concurency'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 03cbe48474e09a98f65327b0cea2a2f80ba7ff1a
[INFO] checking sinagajunior/rust-concurency against master#03eb45452305f2d52348279d0caa5fc1f12c438d for pr-138176
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsinagajunior%2Frust-concurency" "/workspace/builds/worker-1-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/sinagajunior/rust-concurency on toolchain 03eb45452305f2d52348279d0caa5fc1f12c438d
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+03eb45452305f2d52348279d0caa5fc1f12c438d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/sinagajunior/rust-concurency
[INFO] finished tweaking git repo https://github.com/sinagajunior/rust-concurency
[INFO] tweaked toml for git repo https://github.com/sinagajunior/rust-concurency written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/sinagajunior/rust-concurency 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" "+03eb45452305f2d52348279d0caa5fc1f12c438d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/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@sha256:1680c8fbd8dfb46fcd6d22e546df16ab0e007457dc29fcd9e987cdd5077fd1af" "/opt/rustwide/cargo-home/bin/cargo" "+03eb45452305f2d52348279d0caa5fc1f12c438d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cda3f89584237ed0a7cb3425fd6e811698568e896c7714eb3fa4e74b9cc5e121
[INFO] running `Command { std: "docker" "start" "-a" "cda3f89584237ed0a7cb3425fd6e811698568e896c7714eb3fa4e74b9cc5e121", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cda3f89584237ed0a7cb3425fd6e811698568e896c7714eb3fa4e74b9cc5e121", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cda3f89584237ed0a7cb3425fd6e811698568e896c7714eb3fa4e74b9cc5e121", kill_on_drop: false }`
[INFO] [stdout] cda3f89584237ed0a7cb3425fd6e811698568e896c7714eb3fa4e74b9cc5e121
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/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@sha256:1680c8fbd8dfb46fcd6d22e546df16ab0e007457dc29fcd9e987cdd5077fd1af" "/opt/rustwide/cargo-home/bin/cargo" "+03eb45452305f2d52348279d0caa5fc1f12c438d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9a269701258a35671b05d9e02fbd40fb6730b588ff4b45353cac84723c1fb876
[INFO] running `Command { std: "docker" "start" "-a" "9a269701258a35671b05d9e02fbd40fb6730b588ff4b45353cac84723c1fb876", kill_on_drop: false }`
[INFO] [stderr]     Checking rust-concurency v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused imports: `error` and `result`
[INFO] [stdout]   --> src/main.rs:13:15
[INFO] [stdout]    |
[INFO] [stdout] 13 |     use std::{error, result};
[INFO] [stdout]    |               ^^^^^  ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]    --> src/main.rs:111:17
[INFO] [stdout]     |
[INFO] [stdout] 111 |             for i in 0..5 {
[INFO] [stdout]     |                 ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]    --> src/main.rs:134:17
[INFO] [stdout]     |
[INFO] [stdout] 134 |             for i in 0..5 {
[INFO] [stdout]     |                 ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]    --> src/main.rs:183:13
[INFO] [stdout]     |
[INFO] [stdout] 183 |         for i in 0..10 {
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:94:13
[INFO] [stdout]    |
[INFO] [stdout] 94 |             sender.send("Hello from thread".to_string());
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 94 |             let _ = sender.send("Hello from thread".to_string());
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/main.rs:113:17
[INFO] [stdout]     |
[INFO] [stdout] 113 |                 sender.send("Hello from thread".to_string());
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 113 |                 let _ = sender.send("Hello from thread".to_string());
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/main.rs:115:13
[INFO] [stdout]     |
[INFO] [stdout] 115 |             sender.send("Exit".to_string());
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 115 |             let _ = sender.send("Exit".to_string());
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/main.rs:136:17
[INFO] [stdout]     |
[INFO] [stdout] 136 |                 sender.send("Hello from thread".to_string());
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 136 |                 let _ = sender.send("Hello from thread".to_string());
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.09s
[INFO] running `Command { std: "docker" "inspect" "9a269701258a35671b05d9e02fbd40fb6730b588ff4b45353cac84723c1fb876", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9a269701258a35671b05d9e02fbd40fb6730b588ff4b45353cac84723c1fb876", kill_on_drop: false }`
[INFO] [stdout] 9a269701258a35671b05d9e02fbd40fb6730b588ff4b45353cac84723c1fb876