[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#9b49d8c6c904f63eb486fe51b14bbe0aa2feda4c for pr-79472
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftnas%2Fword-ladder" "/workspace/builds/worker-10/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-10/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tnas/word-ladder on toolchain 9b49d8c6c904f63eb486fe51b14bbe0aa2feda4c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9b49d8c6c904f63eb486fe51b14bbe0aa2feda4c" "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-10/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" "+9b49d8c6c904f63eb486fe51b14bbe0aa2feda4c" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+9b49d8c6c904f63eb486fe51b14bbe0aa2feda4c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ad764bcce612025559d745ad3f752b256d05f10c42d9337647b11f68f2d1bd15
[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" "ad764bcce612025559d745ad3f752b256d05f10c42d9337647b11f68f2d1bd15", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ad764bcce612025559d745ad3f752b256d05f10c42d9337647b11f68f2d1bd15", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ad764bcce612025559d745ad3f752b256d05f10c42d9337647b11f68f2d1bd15", kill_on_drop: false }`
[INFO] [stdout] ad764bcce612025559d745ad3f752b256d05f10c42d9337647b11f68f2d1bd15
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+9b49d8c6c904f63eb486fe51b14bbe0aa2feda4c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fe1c52e8b6608094dc0367550ed626df09af7a934ffe1dc7d3c9c7cc50506a57
[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" "fe1c52e8b6608094dc0367550ed626df09af7a934ffe1dc7d3c9c7cc50506a57", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]     Checking lazy_static v1.4.0
[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 4.24s
[INFO] running `Command { std: "docker" "inspect" "fe1c52e8b6608094dc0367550ed626df09af7a934ffe1dc7d3c9c7cc50506a57", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fe1c52e8b6608094dc0367550ed626df09af7a934ffe1dc7d3c9c7cc50506a57", kill_on_drop: false }`
[INFO] [stdout] fe1c52e8b6608094dc0367550ed626df09af7a934ffe1dc7d3c9c7cc50506a57