[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] testing connesc/sudoku-rs against beta-2021-09-08 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fconnesc%2Fsudoku-rs" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/connesc/sudoku-rs on toolchain beta-2021-09-08
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "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-3/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" "+beta-2021-09-08" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7726b606265bdcf793affdbaf52f57f48a112a4fe12b218069ed13b50fc6f7f2
[INFO] running `Command { std: "docker" "start" "-a" "7726b606265bdcf793affdbaf52f57f48a112a4fe12b218069ed13b50fc6f7f2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7726b606265bdcf793affdbaf52f57f48a112a4fe12b218069ed13b50fc6f7f2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7726b606265bdcf793affdbaf52f57f48a112a4fe12b218069ed13b50fc6f7f2", kill_on_drop: false }`
[INFO] [stdout] 7726b606265bdcf793affdbaf52f57f48a112a4fe12b218069ed13b50fc6f7f2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ad5690fc724d382fc71c385d56473908b57cd39b33d52e528918344fba6af4ff
[INFO] running `Command { std: "docker" "start" "-a" "ad5690fc724d382fc71c385d56473908b57cd39b33d52e528918344fba6af4ff", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.84
[INFO] [stderr]    Compiling getrandom v0.2.2
[INFO] [stderr]    Compiling rand_core v0.6.1
[INFO] [stderr]    Compiling rand_chacha v0.3.0
[INFO] [stderr]    Compiling rand v0.8.3
[INFO] [stderr]    Compiling 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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 7.55s
[INFO] running `Command { std: "docker" "inspect" "ad5690fc724d382fc71c385d56473908b57cd39b33d52e528918344fba6af4ff", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ad5690fc724d382fc71c385d56473908b57cd39b33d52e528918344fba6af4ff", kill_on_drop: false }`
[INFO] [stdout] ad5690fc724d382fc71c385d56473908b57cd39b33d52e528918344fba6af4ff
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 67cd0a6854dc6eaa33005b220626133b3381656816ca4d1f5af6989c1243993b
[INFO] running `Command { std: "docker" "start" "-a" "67cd0a6854dc6eaa33005b220626133b3381656816ca4d1f5af6989c1243993b", kill_on_drop: false }`
[INFO] [stderr]    Compiling 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: 1 warning emitted
[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] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 1.18s
[INFO] running `Command { std: "docker" "inspect" "67cd0a6854dc6eaa33005b220626133b3381656816ca4d1f5af6989c1243993b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "67cd0a6854dc6eaa33005b220626133b3381656816ca4d1f5af6989c1243993b", kill_on_drop: false }`
[INFO] [stdout] 67cd0a6854dc6eaa33005b220626133b3381656816ca4d1f5af6989c1243993b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 893bae11a56c2e7393363be35a105639cc3398a30e1942c994cff1ece792fa17
[INFO] running `Command { std: "docker" "start" "-a" "893bae11a56c2e7393363be35a105639cc3398a30e1942c994cff1ece792fa17", kill_on_drop: false }`
[INFO] [stderr] warning: unused borrow that must be used
[INFO] [stderr]    --> src/lib.rs:335:5
[INFO] [stderr]     |
[INFO] [stderr] 335 |     &mut items[..len].shuffle(rng);
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]     |
[INFO] [stderr] 335 |     let _ = &mut items[..len].shuffle(rng);
[INFO] [stderr]     |     +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: `sudoku` (lib) generated 1 warning
[INFO] [stderr] warning: `sudoku` (lib test) generated 1 warning (1 duplicate)
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/sudoku-2866ce44e74aca5f)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/sudoku-a15469964cf9f28d)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests sudoku
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "893bae11a56c2e7393363be35a105639cc3398a30e1942c994cff1ece792fa17", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "893bae11a56c2e7393363be35a105639cc3398a30e1942c994cff1ece792fa17", kill_on_drop: false }`
[INFO] [stdout] 893bae11a56c2e7393363be35a105639cc3398a30e1942c994cff1ece792fa17