[INFO] cloning repository https://github.com/tnas/word-ladder
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tnas/word-ladder" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftnas%2Fword-ladder", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftnas%2Fword-ladder'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 86e71e4bccf17ddb8652deb58a3bfa36748cfa10
[INFO] checking tnas/word-ladder against try#6f12b8fe67b4eed2e838dab803ed9493b9d62c0f for pr-79073
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftnas%2Fword-ladder" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tnas/word-ladder on toolchain 6f12b8fe67b4eed2e838dab803ed9493b9d62c0f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f12b8fe67b4eed2e838dab803ed9493b9d62c0f" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/tnas/word-ladder
[INFO] finished tweaking git repo https://github.com/tnas/word-ladder
[INFO] tweaked toml for git repo https://github.com/tnas/word-ladder written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/tnas/word-ladder already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f12b8fe67b4eed2e838dab803ed9493b9d62c0f" "fetch" "--locked" "--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-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+6f12b8fe67b4eed2e838dab803ed9493b9d62c0f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 19c24e19182a88351404bbc96a8b7d1cbb486508c881fd0b03630d46c640a2ed
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "19c24e19182a88351404bbc96a8b7d1cbb486508c881fd0b03630d46c640a2ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "19c24e19182a88351404bbc96a8b7d1cbb486508c881fd0b03630d46c640a2ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "19c24e19182a88351404bbc96a8b7d1cbb486508c881fd0b03630d46c640a2ed", kill_on_drop: false }`
[INFO] [stdout] 19c24e19182a88351404bbc96a8b7d1cbb486508c881fd0b03630d46c640a2ed
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+6f12b8fe67b4eed2e838dab803ed9493b9d62c0f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 43cb863b946f7a9035b6ce68e11e09c9b8d2b427feb3335fa7ff04aae5685597
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "43cb863b946f7a9035b6ce68e11e09c9b8d2b427feb3335fa7ff04aae5685597", kill_on_drop: false }`
[INFO] [stderr]    Compiling crossbeam-utils v0.8.0
[INFO] [stderr]     Checking word-ladder v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/ang.rs:179:9
[INFO] [stdout]     |
[INFO] [stdout] 179 |     let mut word_levels: Vec<RwLock<usize>> = std::iter::repeat_with(|| RwLock::new(usize::MAX)).take(n_words).collect();
[INFO] [stdout]     |         ----^^^^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/ang.rs:183:9
[INFO] [stdout]     |
[INFO] [stdout] 183 |     let mut level_checked_to_die: Vec<RwLock<bool>> = std::iter::repeat_with(|| RwLock::new(false)).take(n_words).collect();
[INFO] [stdout]     |         ----^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/ang.rs:179:9
[INFO] [stdout]     |
[INFO] [stdout] 179 |     let mut word_levels: Vec<RwLock<usize>> = std::iter::repeat_with(|| RwLock::new(usize::MAX)).take(n_words).collect();
[INFO] [stdout]     |         ----^^^^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/ang.rs:183:9
[INFO] [stdout]     |
[INFO] [stdout] 183 |     let mut level_checked_to_die: Vec<RwLock<bool>> = std::iter::repeat_with(|| RwLock::new(false)).take(n_words).collect();
[INFO] [stdout]     |         ----^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.40s
[INFO] running `Command { std: "docker" "inspect" "43cb863b946f7a9035b6ce68e11e09c9b8d2b427feb3335fa7ff04aae5685597", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "43cb863b946f7a9035b6ce68e11e09c9b8d2b427feb3335fa7ff04aae5685597", kill_on_drop: false }`
[INFO] [stdout] 43cb863b946f7a9035b6ce68e11e09c9b8d2b427feb3335fa7ff04aae5685597