[INFO] cloning repository https://github.com/connesc/sudoku-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/connesc/sudoku-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fconnesc%2Fsudoku-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fconnesc%2Fsudoku-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0088c8377ff84527a1d49db816f17b883deb5df5
[INFO] checking connesc/sudoku-rs against try#cac44d9528e3bbbdaa1537d187bd489ccc5de18c for pr-91141
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fconnesc%2Fsudoku-rs" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/connesc/sudoku-rs on toolchain cac44d9528e3bbbdaa1537d187bd489ccc5de18c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/connesc/sudoku-rs
[INFO] finished tweaking git repo https://github.com/connesc/sudoku-rs
[INFO] tweaked toml for git repo https://github.com/connesc/sudoku-rs written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/connesc/sudoku-rs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded rand_core v0.6.1
[INFO] [stderr]   Downloaded libc v0.2.84
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 93fad0f606daa3c1c693091972d1a1667b4e6143f380af6d2265ea7b5f2f99b6
[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" "93fad0f606daa3c1c693091972d1a1667b4e6143f380af6d2265ea7b5f2f99b6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "93fad0f606daa3c1c693091972d1a1667b4e6143f380af6d2265ea7b5f2f99b6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "93fad0f606daa3c1c693091972d1a1667b4e6143f380af6d2265ea7b5f2f99b6", kill_on_drop: false }`
[INFO] [stdout] 93fad0f606daa3c1c693091972d1a1667b4e6143f380af6d2265ea7b5f2f99b6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d00bfd9c25bc4a03d0a304bd8a184910fffea1412cf72a55d9a7e8a908cc8af6
[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" "d00bfd9c25bc4a03d0a304bd8a184910fffea1412cf72a55d9a7e8a908cc8af6", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.84
[INFO] [stderr]     Checking ppv-lite86 v0.2.10
[INFO] [stderr]     Checking getrandom v0.2.2
[INFO] [stderr]     Checking rand_core v0.6.1
[INFO] [stderr]     Checking rand_chacha v0.3.0
[INFO] [stderr]     Checking rand v0.8.3
[INFO] [stderr]     Checking sudoku v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/lib.rs:335:5
[INFO] [stdout]     |
[INFO] [stdout] 335 |     &mut items[..len].shuffle(rng);
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 335 |     let _ = &mut items[..len].shuffle(rng);
[INFO] [stdout]     |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/lib.rs:335:5
[INFO] [stdout]     |
[INFO] [stdout] 335 |     &mut items[..len].shuffle(rng);
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 335 |     let _ = &mut items[..len].shuffle(rng);
[INFO] [stdout]     |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 7.27s
[INFO] running `Command { std: "docker" "inspect" "d00bfd9c25bc4a03d0a304bd8a184910fffea1412cf72a55d9a7e8a908cc8af6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d00bfd9c25bc4a03d0a304bd8a184910fffea1412cf72a55d9a7e8a908cc8af6", kill_on_drop: false }`
[INFO] [stdout] d00bfd9c25bc4a03d0a304bd8a184910fffea1412cf72a55d9a7e8a908cc8af6