[INFO] fetching crate monotonic-timer 1.0.0...
[INFO] checking monotonic-timer-1.0.0 against master#be181dd75c83d72fcc95538e235768bc367b76b9 for pr-140208
[INFO] extracting crate monotonic-timer 1.0.0 into /workspace/builds/worker-6-tc1/source
[INFO] validating manifest of crates.io crate monotonic-timer 1.0.0 on toolchain be181dd75c83d72fcc95538e235768bc367b76b9
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+be181dd75c83d72fcc95538e235768bc367b76b9" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate monotonic-timer 1.0.0
[INFO] finished tweaking crates.io crate monotonic-timer 1.0.0
[INFO] tweaked toml for crates.io crate monotonic-timer 1.0.0 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" "+be181dd75c83d72fcc95538e235768bc367b76b9" "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" "+be181dd75c83d72fcc95538e235768bc367b76b9" "fetch" "--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: "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:b0b074c097205a61b89e8ad263052f976b2b332c4dc5f02aef1fe52501660d6e" "/opt/rustwide/cargo-home/bin/cargo" "+be181dd75c83d72fcc95538e235768bc367b76b9" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c9558a6af99d64fdd2840a8fb131b459a966c44fab3ccafc121f4167f905819a
[INFO] running `Command { std: "docker" "start" "-a" "c9558a6af99d64fdd2840a8fb131b459a966c44fab3ccafc121f4167f905819a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c9558a6af99d64fdd2840a8fb131b459a966c44fab3ccafc121f4167f905819a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c9558a6af99d64fdd2840a8fb131b459a966c44fab3ccafc121f4167f905819a", kill_on_drop: false }`
[INFO] [stdout] c9558a6af99d64fdd2840a8fb131b459a966c44fab3ccafc121f4167f905819a
[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:b0b074c097205a61b89e8ad263052f976b2b332c4dc5f02aef1fe52501660d6e" "/opt/rustwide/cargo-home/bin/cargo" "+be181dd75c83d72fcc95538e235768bc367b76b9" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ef20ce788cba0a998a2632f694e610142790857564b9c9eb0fde6bb8643bb143
[INFO] running `Command { std: "docker" "start" "-a" "ef20ce788cba0a998a2632f694e610142790857564b9c9eb0fde6bb8643bb143", kill_on_drop: false }`
[INFO] [stderr]     Checking monotonic-timer v1.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/lib.rs:228:25
[INFO] [stdout]     |
[INFO] [stdout] 228 |                     let _ = waiter.condvar.wait(lock);
[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] 228 |                     let _unused = waiter.condvar.wait(lock);
[INFO] [stdout]     |                          ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 228 -                     let _ = waiter.condvar.wait(lock);
[INFO] [stdout] 228 +                     drop(waiter.condvar.wait(lock));
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `monotonic-timer` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/lib.rs:228:25
[INFO] [stdout]     |
[INFO] [stdout] 228 |                     let _ = waiter.condvar.wait(lock);
[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] 228 |                     let _unused = waiter.condvar.wait(lock);
[INFO] [stdout]     |                          ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 228 -                     let _ = waiter.condvar.wait(lock);
[INFO] [stdout] 228 +                     drop(waiter.condvar.wait(lock));
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `monotonic-timer` (lib test) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "ef20ce788cba0a998a2632f694e610142790857564b9c9eb0fde6bb8643bb143", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ef20ce788cba0a998a2632f694e610142790857564b9c9eb0fde6bb8643bb143", kill_on_drop: false }`
[INFO] [stdout] ef20ce788cba0a998a2632f694e610142790857564b9c9eb0fde6bb8643bb143