[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] checking DemonWav/idiots-delight against try#ddcf048784667508cd676fef4667f88ae15628a3 for pr-148271
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FDemonWav%2Fidiots-delight" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/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-4-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/DemonWav/idiots-delight on toolchain ddcf048784667508cd676fef4667f88ae15628a3
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ddcf048784667508cd676fef4667f88ae15628a3" "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" "+ddcf048784667508cd676fef4667f88ae15628a3" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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" "+ddcf048784667508cd676fef4667f88ae15628a3" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c827fd9930d76e172ca9749c21be363935a789f1bb8d74bc188fc1f4723b5537
[INFO] running `Command { std: "docker" "start" "-a" "c827fd9930d76e172ca9749c21be363935a789f1bb8d74bc188fc1f4723b5537", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c827fd9930d76e172ca9749c21be363935a789f1bb8d74bc188fc1f4723b5537", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c827fd9930d76e172ca9749c21be363935a789f1bb8d74bc188fc1f4723b5537", kill_on_drop: false }`
[INFO] [stdout] c827fd9930d76e172ca9749c21be363935a789f1bb8d74bc188fc1f4723b5537
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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" "+ddcf048784667508cd676fef4667f88ae15628a3" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 24646f2bd09083bc853baeb98b5ed15e7d19565964182a49b569da9578e7132f
[INFO] running `Command { std: "docker" "start" "-a" "24646f2bd09083bc853baeb98b5ed15e7d19565964182a49b569da9578e7132f", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]    Compiling getrandom v0.1.13
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]     Checking ppv-lite86 v0.2.6
[INFO] [stderr]     Checking nodrop v0.1.14
[INFO] [stderr]     Checking itoa v0.4.4
[INFO] [stderr]     Checking c2-chacha v0.2.3
[INFO] [stderr]     Checking num_cpus v1.11.0
[INFO] [stderr]     Checking num-format v0.4.0
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking rand v0.7.2
[INFO] [stderr]     Checking 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" test) 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/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" "24646f2bd09083bc853baeb98b5ed15e7d19565964182a49b569da9578e7132f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "24646f2bd09083bc853baeb98b5ed15e7d19565964182a49b569da9578e7132f", kill_on_drop: false }`
[INFO] [stdout] 24646f2bd09083bc853baeb98b5ed15e7d19565964182a49b569da9578e7132f
