[INFO] cloning repository https://github.com/sunnywhy/rust-thread-pool
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/sunnywhy/rust-thread-pool" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsunnywhy%2Frust-thread-pool", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsunnywhy%2Frust-thread-pool'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 6227f5fded0d0cecad295c6151b1fb82c4c45acf
[INFO] checking sunnywhy/rust-thread-pool against master#f82664191d0e8764b7435b9d72eb0e366b8b1464 for pr-83354
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsunnywhy%2Frust-thread-pool" "/workspace/builds/worker-10/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-10/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/sunnywhy/rust-thread-pool on toolchain f82664191d0e8764b7435b9d72eb0e366b8b1464
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/sunnywhy/rust-thread-pool
[INFO] finished tweaking git repo https://github.com/sunnywhy/rust-thread-pool
[INFO] tweaked toml for git repo https://github.com/sunnywhy/rust-thread-pool written to /workspace/builds/worker-10/source/Cargo.toml
[INFO] crate git repo https://github.com/sunnywhy/rust-thread-pool already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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" "rustops/crates-build-env@sha256:4f92631de1aa59f8320307485d3b3c869a5c90ab1d76ce2cffab9807b8c9a1fb" "/opt/rustwide/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 54418b21a1767abf3ccd84b2ae63a7d925140504ca11c5d2ab27a3ca0943b9df
[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" "54418b21a1767abf3ccd84b2ae63a7d925140504ca11c5d2ab27a3ca0943b9df", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "54418b21a1767abf3ccd84b2ae63a7d925140504ca11c5d2ab27a3ca0943b9df", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "54418b21a1767abf3ccd84b2ae63a7d925140504ca11c5d2ab27a3ca0943b9df", kill_on_drop: false }`
[INFO] [stdout] 54418b21a1767abf3ccd84b2ae63a7d925140504ca11c5d2ab27a3ca0943b9df
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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" "rustops/crates-build-env@sha256:4f92631de1aa59f8320307485d3b3c869a5c90ab1d76ce2cffab9807b8c9a1fb" "/opt/rustwide/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 68570f342faf56a1bf6071f706d79978b4739fb16761eded92894918e1d48239
[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" "68570f342faf56a1bf6071f706d79978b4739fb16761eded92894918e1d48239", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.77
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking rust_thread_pool v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `MutexGuard` that must be used
[INFO] [stdout]   --> src/main.rs:38:13
[INFO] [stdout]    |
[INFO] [stdout] 38 |             self.empty_trigger.lock().expect("Unable to notify all joining threads");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: if unused the Mutex will immediately unlock
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `MutexGuard` that must be used
[INFO] [stdout]   --> src/main.rs:38:13
[INFO] [stdout]    |
[INFO] [stdout] 38 |             self.empty_trigger.lock().expect("Unable to notify all joining threads");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: if unused the Mutex will immediately unlock
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.33s
[INFO] running `Command { std: "docker" "inspect" "68570f342faf56a1bf6071f706d79978b4739fb16761eded92894918e1d48239", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "68570f342faf56a1bf6071f706d79978b4739fb16761eded92894918e1d48239", kill_on_drop: false }`
[INFO] [stdout] 68570f342faf56a1bf6071f706d79978b4739fb16761eded92894918e1d48239