[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#f70ee28831acc074c109afab32d287057c3eca46 for pr-149389
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FDemonWav%2Fidiots-delight" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-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-6-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/DemonWav/idiots-delight on toolchain f70ee28831acc074c109afab32d287057c3eca46
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+f70ee28831acc074c109afab32d287057c3eca46" "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" "+f70ee28831acc074c109afab32d287057c3eca46" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:94a0c148923f5b2b52a63ef0eeb1882ad339ab61bce784c8077cbe41c61feb6c" "/opt/rustwide/cargo-home/bin/cargo" "+f70ee28831acc074c109afab32d287057c3eca46" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0d40c124e27e26933f577f3f8b6364e54e83984e52556cb7a3d27096da30fc3d
[INFO] running `Command { std: "docker" "start" "-a" "0d40c124e27e26933f577f3f8b6364e54e83984e52556cb7a3d27096da30fc3d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0d40c124e27e26933f577f3f8b6364e54e83984e52556cb7a3d27096da30fc3d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0d40c124e27e26933f577f3f8b6364e54e83984e52556cb7a3d27096da30fc3d", kill_on_drop: false }`
[INFO] [stdout] 0d40c124e27e26933f577f3f8b6364e54e83984e52556cb7a3d27096da30fc3d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:94a0c148923f5b2b52a63ef0eeb1882ad339ab61bce784c8077cbe41c61feb6c" "/opt/rustwide/cargo-home/bin/cargo" "+f70ee28831acc074c109afab32d287057c3eca46" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 245c42695f81db6f5709341e8ff55a66faf746ae9ba9208d94682ba6d40b3ad6
[INFO] running `Command { std: "docker" "start" "-a" "245c42695f81db6f5709341e8ff55a66faf746ae9ba9208d94682ba6d40b3ad6", 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 itoa v0.4.4
[INFO] [stderr]     Checking c2-chacha v0.2.3
[INFO] [stderr]     Checking num-format v0.4.0
[INFO] [stderr]     Checking num_cpus v1.11.0
[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") 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" test) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "245c42695f81db6f5709341e8ff55a66faf746ae9ba9208d94682ba6d40b3ad6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "245c42695f81db6f5709341e8ff55a66faf746ae9ba9208d94682ba6d40b3ad6", kill_on_drop: false }`
[INFO] [stdout] 245c42695f81db6f5709341e8ff55a66faf746ae9ba9208d94682ba6d40b3ad6
