[INFO] cloning repository https://github.com/Buldugmaster99/Sudoku-Solver-2
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Buldugmaster99/Sudoku-Solver-2" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBuldugmaster99%2FSudoku-Solver-2", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBuldugmaster99%2FSudoku-Solver-2'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 151eb3d4682ba98ed1f59c3ea44add760829afed
[INFO] checking Buldugmaster99/Sudoku-Solver-2 against master#00bfd6b2734d9c28a147bf237490995731781fdd for pr-117984
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBuldugmaster99%2FSudoku-Solver-2" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Buldugmaster99/Sudoku-Solver-2 on toolchain 00bfd6b2734d9c28a147bf237490995731781fdd
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+00bfd6b2734d9c28a147bf237490995731781fdd" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Buldugmaster99/Sudoku-Solver-2
[INFO] finished tweaking git repo https://github.com/Buldugmaster99/Sudoku-Solver-2
[INFO] tweaked toml for git repo https://github.com/Buldugmaster99/Sudoku-Solver-2 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/Buldugmaster99/Sudoku-Solver-2 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+00bfd6b2734d9c28a147bf237490995731781fdd" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+00bfd6b2734d9c28a147bf237490995731781fdd" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9be1f565f9f820e2cf0fd7ba5f2cab1a28208fd2c4e6a96debfd631a2d1a1e2b
[INFO] running `Command { std: "docker" "start" "-a" "9be1f565f9f820e2cf0fd7ba5f2cab1a28208fd2c4e6a96debfd631a2d1a1e2b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9be1f565f9f820e2cf0fd7ba5f2cab1a28208fd2c4e6a96debfd631a2d1a1e2b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9be1f565f9f820e2cf0fd7ba5f2cab1a28208fd2c4e6a96debfd631a2d1a1e2b", kill_on_drop: false }`
[INFO] [stdout] 9be1f565f9f820e2cf0fd7ba5f2cab1a28208fd2c4e6a96debfd631a2d1a1e2b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+00bfd6b2734d9c28a147bf237490995731781fdd" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ab653127de6ac3208d256e57f0e405c9aa2071225d3e6ab436a11af557ee3ba5
[INFO] running `Command { std: "docker" "start" "-a" "ab653127de6ac3208d256e57f0e405c9aa2071225d3e6ab436a11af557ee3ba5", kill_on_drop: false }`
[INFO] [stderr]     Checking Sudoku v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: crate `Sudoku` should have a snake case name
[INFO] [stdout]   |
[INFO] [stdout]   = help: convert the identifier to snake case: `sudoku`
[INFO] [stdout]   = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: crate `Sudoku` should have a snake case name
[INFO] [stdout]   |
[INFO] [stdout]   = help: convert the identifier to snake case: `sudoku`
[INFO] [stdout]   = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:45:3
[INFO] [stdout]    |
[INFO] [stdout] 45 |         write!(formatter, "\n ");
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:47:4
[INFO] [stdout]    |
[INFO] [stdout] 47 |             write!(formatter, "--- ");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:49:5
[INFO] [stdout]    |
[INFO] [stdout] 49 |                 write!(formatter, " ");
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:45:3
[INFO] [stdout]    |
[INFO] [stdout] 45 |         write!(formatter, "\n ");
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:52:3
[INFO] [stdout]    |
[INFO] [stdout] 52 |         write!(formatter, "\n");
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:55:4
[INFO] [stdout]    |
[INFO] [stdout] 55 |             write!(formatter, "|");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:47:4
[INFO] [stdout]    |
[INFO] [stdout] 47 |             write!(formatter, "--- ");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:58:6
[INFO] [stdout]    |
[INFO] [stdout] 58 |                     write!(formatter, "   ");
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:49:5
[INFO] [stdout]    |
[INFO] [stdout] 49 |                 write!(formatter, " ");
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:60:6
[INFO] [stdout]    |
[INFO] [stdout] 60 |                     write!(formatter, " {} ", self.data[row as usize][col as usize]);
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:52:3
[INFO] [stdout]    |
[INFO] [stdout] 52 |         write!(formatter, "\n");
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:55:4
[INFO] [stdout]    |
[INFO] [stdout] 55 |             write!(formatter, "|");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:63:6
[INFO] [stdout]    |
[INFO] [stdout] 63 |                     write!(formatter, "|");
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:65:5
[INFO] [stdout]    |
[INFO] [stdout] 65 |                 write!(formatter, "|");
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:58:6
[INFO] [stdout]    |
[INFO] [stdout] 58 |                     write!(formatter, "   ");
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:67:4
[INFO] [stdout]    |
[INFO] [stdout] 67 |             write!(formatter, "\n");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:60:6
[INFO] [stdout]    |
[INFO] [stdout] 60 |                     write!(formatter, " {} ", self.data[row as usize][col as usize]);
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:69:4
[INFO] [stdout]    |
[INFO] [stdout] 69 |             write!(formatter, " ");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:63:6
[INFO] [stdout]    |
[INFO] [stdout] 63 |                     write!(formatter, "|");
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:72:6
[INFO] [stdout]    |
[INFO] [stdout] 72 |                     write!(formatter, "=== ");
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:65:5
[INFO] [stdout]    |
[INFO] [stdout] 65 |                 write!(formatter, "|");
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:74:7
[INFO] [stdout]    |
[INFO] [stdout] 74 |                         write!(formatter, " ");
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:67:4
[INFO] [stdout]    |
[INFO] [stdout] 67 |             write!(formatter, "\n");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:79:6
[INFO] [stdout]    |
[INFO] [stdout] 79 |                     write!(formatter, "--- ");
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:69:4
[INFO] [stdout]    |
[INFO] [stdout] 69 |             write!(formatter, " ");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:81:7
[INFO] [stdout]    |
[INFO] [stdout] 81 |                         write!(formatter, " ");
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:72:6
[INFO] [stdout]    |
[INFO] [stdout] 72 |                     write!(formatter, "=== ");
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:85:4
[INFO] [stdout]    |
[INFO] [stdout] 85 |             write!(formatter, "\n");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:74:7
[INFO] [stdout]    |
[INFO] [stdout] 74 |                         write!(formatter, " ");
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:79:6
[INFO] [stdout]    |
[INFO] [stdout] 79 |                     write!(formatter, "--- ");
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:81:7
[INFO] [stdout]    |
[INFO] [stdout] 81 |                         write!(formatter, " ");
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:85:4
[INFO] [stdout]    |
[INFO] [stdout] 85 |             write!(formatter, "\n");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 17 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 17 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.07s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: rustc-serialize v0.3.24
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 1`
[INFO] running `Command { std: "docker" "inspect" "ab653127de6ac3208d256e57f0e405c9aa2071225d3e6ab436a11af557ee3ba5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ab653127de6ac3208d256e57f0e405c9aa2071225d3e6ab436a11af557ee3ba5", kill_on_drop: false }`
[INFO] [stdout] ab653127de6ac3208d256e57f0e405c9aa2071225d3e6ab436a11af557ee3ba5
[INFO] checking Buldugmaster99/Sudoku-Solver-2 against try#aa7c6ba69acce8b10a275eabfe6157ea72c8b599 for pr-117984
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBuldugmaster99%2FSudoku-Solver-2" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Buldugmaster99/Sudoku-Solver-2 on toolchain aa7c6ba69acce8b10a275eabfe6157ea72c8b599
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+aa7c6ba69acce8b10a275eabfe6157ea72c8b599" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Buldugmaster99/Sudoku-Solver-2
[INFO] finished tweaking git repo https://github.com/Buldugmaster99/Sudoku-Solver-2
[INFO] tweaked toml for git repo https://github.com/Buldugmaster99/Sudoku-Solver-2 written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/Buldugmaster99/Sudoku-Solver-2 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+aa7c6ba69acce8b10a275eabfe6157ea72c8b599" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+aa7c6ba69acce8b10a275eabfe6157ea72c8b599" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 47421693b69adc6a45aeb5e8bdaf2e17ab946735abd6858fcf439fe9292549ff
[INFO] running `Command { std: "docker" "start" "-a" "47421693b69adc6a45aeb5e8bdaf2e17ab946735abd6858fcf439fe9292549ff", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "47421693b69adc6a45aeb5e8bdaf2e17ab946735abd6858fcf439fe9292549ff", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "47421693b69adc6a45aeb5e8bdaf2e17ab946735abd6858fcf439fe9292549ff", kill_on_drop: false }`
[INFO] [stdout] 47421693b69adc6a45aeb5e8bdaf2e17ab946735abd6858fcf439fe9292549ff
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+aa7c6ba69acce8b10a275eabfe6157ea72c8b599" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d61bb0876981b726664c24ce2822162e8d5743042d457733c3477b68c1e59c4f
[INFO] running `Command { std: "docker" "start" "-a" "d61bb0876981b726664c24ce2822162e8d5743042d457733c3477b68c1e59c4f", kill_on_drop: false }`
[INFO] [stderr]     Checking rustc-serialize v0.3.24
[INFO] [stdout] error[E0310]: the parameter type `T` may not live long enough
[INFO] [stdout]     --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/rustc-serialize-0.3.24/src/serialize.rs:1155:5
[INFO] [stdout]      |
[INFO] [stdout] 1155 |     fn decode<D: Decoder>(d: &mut D) -> Result<Cow<'static, T>, D::Error> {
[INFO] [stdout]      |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]      |     |
[INFO] [stdout]      |     the parameter type `T` must be valid for the static lifetime...
[INFO] [stdout]      |     ...so that the type `T` will meet its required lifetime bounds...
[INFO] [stdout]      |
[INFO] [stdout] note: ...that is required by this bound
[INFO] [stdout]     --> /rustc/aa7c6ba69acce8b10a275eabfe6157ea72c8b599/library/alloc/src/borrow.rs:180:30
[INFO] [stdout] help: consider adding an explicit lifetime bound
[INFO] [stdout]      |
[INFO] [stdout] 1151 | impl<'a, T: ?Sized + 'static> Decodable for Cow<'a, T>
[INFO] [stdout]      |                    +++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0310`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rustc-serialize` (lib) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "d61bb0876981b726664c24ce2822162e8d5743042d457733c3477b68c1e59c4f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d61bb0876981b726664c24ce2822162e8d5743042d457733c3477b68c1e59c4f", kill_on_drop: false }`
[INFO] [stdout] d61bb0876981b726664c24ce2822162e8d5743042d457733c3477b68c1e59c4f