[INFO] cloning repository https://github.com/suelz/chapter_4
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/suelz/chapter_4" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsuelz%2Fchapter_4", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsuelz%2Fchapter_4'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 5266a4ada4918881254cc79de937fbc229bb69a4
[INFO] checking suelz/chapter_4 against try#f47dd4da3ae8c32c9e65d307bfe640b143e674df for pr-77526
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsuelz%2Fchapter_4" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/suelz/chapter_4 on toolchain f47dd4da3ae8c32c9e65d307bfe640b143e674df
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/suelz/chapter_4
[INFO] finished tweaking git repo https://github.com/suelz/chapter_4
[INFO] tweaked toml for git repo https://github.com/suelz/chapter_4 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/suelz/chapter_4 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a445fc565c0d5c3ecd09688eedea0e5a2045ed77f36e454e6f38ffc5993bea11
[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" "a445fc565c0d5c3ecd09688eedea0e5a2045ed77f36e454e6f38ffc5993bea11", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a445fc565c0d5c3ecd09688eedea0e5a2045ed77f36e454e6f38ffc5993bea11", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a445fc565c0d5c3ecd09688eedea0e5a2045ed77f36e454e6f38ffc5993bea11", kill_on_drop: false }`
[INFO] [stdout] a445fc565c0d5c3ecd09688eedea0e5a2045ed77f36e454e6f38ffc5993bea11
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 38db6db9c6dc1d2cfb351fa488f0898c741cf2838b9619327750f0bdd61cbaa8
[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" "38db6db9c6dc1d2cfb351fa488f0898c741cf2838b9619327750f0bdd61cbaa8", kill_on_drop: false }`
[INFO] [stderr]     Checking ch4 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]   --> src/main.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let word = first_word(&x);
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let mut x = String::from("Conor Kennedy");
[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: unused variable: `word`
[INFO] [stdout]   --> src/main.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let word = first_word(&x);
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[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/main.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let mut x = String::from("Conor Kennedy");
[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: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.27s
[INFO] running `Command { std: "docker" "inspect" "38db6db9c6dc1d2cfb351fa488f0898c741cf2838b9619327750f0bdd61cbaa8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "38db6db9c6dc1d2cfb351fa488f0898c741cf2838b9619327750f0bdd61cbaa8", kill_on_drop: false }`
[INFO] [stdout] 38db6db9c6dc1d2cfb351fa488f0898c741cf2838b9619327750f0bdd61cbaa8