[INFO] cloning repository https://github.com/DemonWav/idiots-delight
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/DemonWav/idiots-delight" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FDemonWav%2Fidiots-delight", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FDemonWav%2Fidiots-delight'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 71a339a925b32cdaaef5678a971f151c10d15e15
[INFO] testing DemonWav/idiots-delight against master#1ef7943ee607160a564655b6596f83670ef95df5 for pr-146098-6
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FDemonWav%2Fidiots-delight" "/workspace/builds/worker-3-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/DemonWav/idiots-delight
[INFO] finished tweaking git repo https://github.com/DemonWav/idiots-delight
[INFO] tweaked toml for git repo https://github.com/DemonWav/idiots-delight written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/DemonWav/idiots-delight on toolchain 1ef7943ee607160a564655b6596f83670ef95df5
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1ef7943ee607160a564655b6596f83670ef95df5" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/DemonWav/idiots-delight 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" "+1ef7943ee607160a564655b6596f83670ef95df5" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded hermit-abi v0.1.3
[INFO] [stderr]   Downloaded num_cpus v1.11.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1ef7943ee607160a564655b6596f83670ef95df5" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0ba22705497ec686bf0db479b5f054287b2c5039304379ff0caf3a18c12e8970
[INFO] running `Command { std: "docker" "start" "-a" "0ba22705497ec686bf0db479b5f054287b2c5039304379ff0caf3a18c12e8970", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0ba22705497ec686bf0db479b5f054287b2c5039304379ff0caf3a18c12e8970", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0ba22705497ec686bf0db479b5f054287b2c5039304379ff0caf3a18c12e8970", kill_on_drop: false }`
[INFO] [stdout] 0ba22705497ec686bf0db479b5f054287b2c5039304379ff0caf3a18c12e8970
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1ef7943ee607160a564655b6596f83670ef95df5" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b2edb6e69dcfbdf4ff10f252bca7c09e7e7917aa578c53c63466c697242f7dc6
[INFO] running `Command { std: "docker" "start" "-a" "b2edb6e69dcfbdf4ff10f252bca7c09e7e7917aa578c53c63466c697242f7dc6", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]    Compiling getrandom v0.1.13
[INFO] [stderr]    Compiling ppv-lite86 v0.2.6
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]    Compiling itoa v0.4.4
[INFO] [stderr]    Compiling c2-chacha v0.2.3
[INFO] [stderr]    Compiling num-format v0.4.0
[INFO] [stderr]    Compiling num_cpus v1.11.0
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling rand_chacha v0.2.1
[INFO] [stderr]    Compiling rand v0.7.2
[INFO] [stderr]    Compiling idiots-delight v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/main.rs:106:13
[INFO] [stdout]     |
[INFO] [stdout] 106 |         let _ = lock.lock().unwrap();
[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] 106 |         let _unused = lock.lock().unwrap();
[INFO] [stdout]     |              ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 106 -         let _ = lock.lock().unwrap();
[INFO] [stdout] 106 +         drop(lock.lock().unwrap());
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `idiots-delight` (bin "idiots-delight") due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "b2edb6e69dcfbdf4ff10f252bca7c09e7e7917aa578c53c63466c697242f7dc6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b2edb6e69dcfbdf4ff10f252bca7c09e7e7917aa578c53c63466c697242f7dc6", kill_on_drop: false }`
[INFO] [stdout] b2edb6e69dcfbdf4ff10f252bca7c09e7e7917aa578c53c63466c697242f7dc6
