[INFO] cloning repository https://github.com/ffjanp/sudoku_solver
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ffjanp/sudoku_solver" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fffjanp%2Fsudoku_solver", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fffjanp%2Fsudoku_solver'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a5129652558878ae06295ea3b7cf9317f731f6c9
[INFO] testing ffjanp/sudoku_solver against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fffjanp%2Fsudoku_solver" "/workspace/builds/worker-88/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-88/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ffjanp/sudoku_solver on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ffjanp/sudoku_solver
[INFO] finished tweaking git repo https://github.com/ffjanp/sudoku_solver
[INFO] tweaked toml for git repo https://github.com/ffjanp/sudoku_solver written to /workspace/builds/worker-88/source/Cargo.toml
[INFO] crate git repo https://github.com/ffjanp/sudoku_solver already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-88/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-88/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" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c52ce6d770bd3c442ca6e52a4a061a39b5ee1aa8688788bf2f9d250bf15b439e
[INFO] running `Command { std: "docker" "start" "-a" "c52ce6d770bd3c442ca6e52a4a061a39b5ee1aa8688788bf2f9d250bf15b439e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c52ce6d770bd3c442ca6e52a4a061a39b5ee1aa8688788bf2f9d250bf15b439e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c52ce6d770bd3c442ca6e52a4a061a39b5ee1aa8688788bf2f9d250bf15b439e", kill_on_drop: false }`
[INFO] [stdout] c52ce6d770bd3c442ca6e52a4a061a39b5ee1aa8688788bf2f9d250bf15b439e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-88/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-88/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" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] eb939e709d1fb2d9ff496ea546a7c31c7ee1e2355c7bef677547cbd54e4aefa6
[INFO] running `Command { std: "docker" "start" "-a" "eb939e709d1fb2d9ff496ea546a7c31c7ee1e2355c7bef677547cbd54e4aefa6", kill_on_drop: false }`
[INFO] [stderr]    Compiling find_transaction v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:72:25
[INFO] [stdout]    |
[INFO] [stdout] 72 |                     let mut possible = self.check(x,y);
[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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.40s
[INFO] running `Command { std: "docker" "inspect" "eb939e709d1fb2d9ff496ea546a7c31c7ee1e2355c7bef677547cbd54e4aefa6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "eb939e709d1fb2d9ff496ea546a7c31c7ee1e2355c7bef677547cbd54e4aefa6", kill_on_drop: false }`
[INFO] [stdout] eb939e709d1fb2d9ff496ea546a7c31c7ee1e2355c7bef677547cbd54e4aefa6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-88/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-88/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" "+1.55.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b6631aff6f049a7541583aa7c8d8f9665aa57d83ee3b7d608eb4da79319940fd
[INFO] running `Command { std: "docker" "start" "-a" "b6631aff6f049a7541583aa7c8d8f9665aa57d83ee3b7d608eb4da79319940fd", kill_on_drop: false }`
[INFO] [stderr]    Compiling find_transaction v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:72:25
[INFO] [stdout]    |
[INFO] [stdout] 72 |                     let mut possible = self.check(x,y);
[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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 1.46s
[INFO] running `Command { std: "docker" "inspect" "b6631aff6f049a7541583aa7c8d8f9665aa57d83ee3b7d608eb4da79319940fd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b6631aff6f049a7541583aa7c8d8f9665aa57d83ee3b7d608eb4da79319940fd", kill_on_drop: false }`
[INFO] [stdout] b6631aff6f049a7541583aa7c8d8f9665aa57d83ee3b7d608eb4da79319940fd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-88/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-88/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" "+1.55.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 61d6b9335ba8d7c8134d4990e7dbb7c5c002ce03073aec5cfe97dc11e2f0f4aa
[INFO] running `Command { std: "docker" "start" "-a" "61d6b9335ba8d7c8134d4990e7dbb7c5c002ce03073aec5cfe97dc11e2f0f4aa", kill_on_drop: false }`
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stdout] 
[INFO] [stderr]   --> src/main.rs:72:25
[INFO] [stdout] running 0 tests
[INFO] [stderr]    |
[INFO] [stdout] 
[INFO] [stderr] 72 |                     let mut possible = self.check(x,y);
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stderr]    |                         ----^^^^^^^^
[INFO] [stdout] 
[INFO] [stderr]    |                         |
[INFO] [stderr]    |                         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: `find_transaction` (bin "find_transaction" test) generated 1 warning
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 10.48s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/find_transaction-bc365bbfbb803d22)
[INFO] running `Command { std: "docker" "inspect" "61d6b9335ba8d7c8134d4990e7dbb7c5c002ce03073aec5cfe97dc11e2f0f4aa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "61d6b9335ba8d7c8134d4990e7dbb7c5c002ce03073aec5cfe97dc11e2f0f4aa", kill_on_drop: false }`
[INFO] [stdout] 61d6b9335ba8d7c8134d4990e7dbb7c5c002ce03073aec5cfe97dc11e2f0f4aa