[INFO] fetching crate simpledi-rs 0.1.0...
[INFO] building simpledi-rs-0.1.0 against master#c7f6aa2869acdbf014d094c6e427e554e160b6db for pr-146237-2
[INFO] extracting crate simpledi-rs 0.1.0 into /workspace/builds/worker-4-tc1/source
[INFO] started tweaking crates.io crate simpledi-rs 0.1.0
[INFO] finished tweaking crates.io crate simpledi-rs 0.1.0
[INFO] tweaked toml for crates.io crate simpledi-rs 0.1.0 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate simpledi-rs 0.1.0 on toolchain c7f6aa2869acdbf014d094c6e427e554e160b6db
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]      Locking 50 packages to latest compatible versions
[INFO] [stderr]       Adding pretty_env_logger v0.3.1 (available: v0.5.0)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded pretty_env_logger v0.3.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4503cb243bc051fc88c33ec804b7a31a82583a2eb6bb4619572f6b74799545af
[INFO] running `Command { std: "docker" "start" "-a" "4503cb243bc051fc88c33ec804b7a31a82583a2eb6bb4619572f6b74799545af", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4503cb243bc051fc88c33ec804b7a31a82583a2eb6bb4619572f6b74799545af", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4503cb243bc051fc88c33ec804b7a31a82583a2eb6bb4619572f6b74799545af", kill_on_drop: false }`
[INFO] [stdout] 4503cb243bc051fc88c33ec804b7a31a82583a2eb6bb4619572f6b74799545af
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] dac3ba4efe5735f59d6b25f53ae2ddb711f9b04de02eb85497f4f59e3b24d8fd
[INFO] running `Command { std: "docker" "start" "-a" "dac3ba4efe5735f59d6b25f53ae2ddb711f9b04de02eb85497f4f59e3b24d8fd", kill_on_drop: false }`
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling env_logger v0.6.2
[INFO] [stderr]    Compiling pretty_env_logger v0.3.1
[INFO] [stderr]    Compiling simpledi-rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]   --> src/di.rs:70:13
[INFO] [stdout]    |
[INFO] [stdout] 70 |         let _ = self.mutex.lock();
[INFO] [stdout]    |             ^ this lock is not assigned to a binding and is immediately dropped
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[deny(let_underscore_lock)]` (part of `#[deny(let_underscore)]`) on by default
[INFO] [stdout] help: consider binding to an unused variable to avoid immediately dropping the value
[INFO] [stdout]    |
[INFO] [stdout] 70 |         let _unused = self.mutex.lock();
[INFO] [stdout]    |              ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]    |
[INFO] [stdout] 70 -         let _ = self.mutex.lock();
[INFO] [stdout] 70 +         drop(self.mutex.lock());
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `simpledi-rs` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "dac3ba4efe5735f59d6b25f53ae2ddb711f9b04de02eb85497f4f59e3b24d8fd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dac3ba4efe5735f59d6b25f53ae2ddb711f9b04de02eb85497f4f59e3b24d8fd", kill_on_drop: false }`
[INFO] [stdout] dac3ba4efe5735f59d6b25f53ae2ddb711f9b04de02eb85497f4f59e3b24d8fd