[INFO] fetching crate thread_timer 0.3.0...
[INFO] checking thread_timer-0.3.0 against master#19f42cb9bb65555e7d95dab7d17573ae6c5d634c for pr-139087
[INFO] extracting crate thread_timer 0.3.0 into /workspace/builds/worker-6-tc1/source
[INFO] validating manifest of crates.io crate thread_timer 0.3.0 on toolchain 19f42cb9bb65555e7d95dab7d17573ae6c5d634c
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+19f42cb9bb65555e7d95dab7d17573ae6c5d634c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate thread_timer 0.3.0
[INFO] finished tweaking crates.io crate thread_timer 0.3.0
[INFO] tweaked toml for crates.io crate thread_timer 0.3.0 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+19f42cb9bb65555e7d95dab7d17573ae6c5d634c" "generate-lockfile" "--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: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+19f42cb9bb65555e7d95dab7d17573ae6c5d634c" "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-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:4b26683ee3c49f365255c425c23003cbf4366de097804722c29c5bbbee3624d2" "/opt/rustwide/cargo-home/bin/cargo" "+19f42cb9bb65555e7d95dab7d17573ae6c5d634c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 19e69b0f5fc4acc0b13d495f0c17dc6c13e9510203079b8a08e4e10db07b9c56
[INFO] running `Command { std: "docker" "start" "-a" "19e69b0f5fc4acc0b13d495f0c17dc6c13e9510203079b8a08e4e10db07b9c56", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "19e69b0f5fc4acc0b13d495f0c17dc6c13e9510203079b8a08e4e10db07b9c56", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "19e69b0f5fc4acc0b13d495f0c17dc6c13e9510203079b8a08e4e10db07b9c56", kill_on_drop: false }`
[INFO] [stdout] 19e69b0f5fc4acc0b13d495f0c17dc6c13e9510203079b8a08e4e10db07b9c56
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:4b26683ee3c49f365255c425c23003cbf4366de097804722c29c5bbbee3624d2" "/opt/rustwide/cargo-home/bin/cargo" "+19f42cb9bb65555e7d95dab7d17573ae6c5d634c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e9e1892a848c8a4cf1d50ac7f61f291c25242ec7e35ed4d8c4264046d5f1e515
[INFO] running `Command { std: "docker" "start" "-a" "e9e1892a848c8a4cf1d50ac7f61f291c25242ec7e35ed4d8c4264046d5f1e515", kill_on_drop: false }`
[INFO] [stderr]     Checking thread_timer v0.3.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/lib.rs:240:13
[INFO] [stdout]     |
[INFO] [stdout] 240 |         let _ = is_waiting_condvar
[INFO] [stdout]     |             ^ this lock is not assigned to a binding and is immediately dropped
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[deny(let_underscore_lock)]` on by default
[INFO] [stdout] help: consider binding to an unused variable to avoid immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 240 |         let _unused = is_waiting_condvar
[INFO] [stdout]     |              ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 240 ~         drop(is_waiting_condvar
[INFO] [stdout] 241 |           .wait_while(is_waiting_lock.lock().unwrap(), |&mut is_waiting| {
[INFO] [stdout] 242 |             is_waiting
[INFO] [stdout] 243 |           })
[INFO] [stdout] 244 ~           .unwrap());
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/lib.rs:240:13
[INFO] [stdout]     |
[INFO] [stdout] 240 |         let _ = is_waiting_condvar
[INFO] [stdout]     |             ^ this lock is not assigned to a binding and is immediately dropped
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[deny(let_underscore_lock)]` on by default
[INFO] [stdout] help: consider binding to an unused variable to avoid immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 240 |         let _unused = is_waiting_condvar
[INFO] [stdout]     |              ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 240 ~         drop(is_waiting_condvar
[INFO] [stdout] 241 |           .wait_while(is_waiting_lock.lock().unwrap(), |&mut is_waiting| {
[INFO] [stdout] 242 |             is_waiting
[INFO] [stdout] 243 |           })
[INFO] [stdout] 244 ~           .unwrap());
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `thread_timer` (lib test) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `thread_timer` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "e9e1892a848c8a4cf1d50ac7f61f291c25242ec7e35ed4d8c4264046d5f1e515", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e9e1892a848c8a4cf1d50ac7f61f291c25242ec7e35ed4d8c4264046d5f1e515", kill_on_drop: false }`
[INFO] [stdout] e9e1892a848c8a4cf1d50ac7f61f291c25242ec7e35ed4d8c4264046d5f1e515