[INFO] fetching crate sudoku-cli 0.2.0...
[INFO] checking sudoku-cli-0.2.0 against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] extracting crate sudoku-cli 0.2.0 into /workspace/builds/worker-5-tc2/source
[INFO] started tweaking crates.io crate sudoku-cli 0.2.0
[INFO] finished tweaking crates.io crate sudoku-cli 0.2.0
[INFO] tweaked toml for crates.io crate sudoku-cli 0.2.0 written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate sudoku-cli 0.2.0 on toolchain 4f260f0f20b3133d20cfb50353c0221943af5796
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate sudoku-cli 0.2.0 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" "+4f260f0f20b3133d20cfb50353c0221943af5796" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e49de7650ea819d0fada5776c35107bbe9a57c3917703b5e3c9a042e0e81804a
[INFO] running `Command { std: "docker" "start" "-a" "e49de7650ea819d0fada5776c35107bbe9a57c3917703b5e3c9a042e0e81804a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e49de7650ea819d0fada5776c35107bbe9a57c3917703b5e3c9a042e0e81804a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e49de7650ea819d0fada5776c35107bbe9a57c3917703b5e3c9a042e0e81804a", kill_on_drop: false }`
[INFO] [stdout] e49de7650ea819d0fada5776c35107bbe9a57c3917703b5e3c9a042e0e81804a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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 -Dunmustuse_in_always_ok" "-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d19500b62fbd93ddc2f257d4a314abfab88b9e12ee94caa8edc2c798d275e45f
[INFO] running `Command { std: "docker" "start" "-a" "d19500b62fbd93ddc2f257d4a314abfab88b9e12ee94caa8edc2c798d275e45f", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]    Compiling syn v1.0.5
[INFO] [stderr]    Compiling unicode-segmentation v1.3.0
[INFO] [stderr]     Checking unicode-width v0.1.6
[INFO] [stderr]    Compiling rayon-core v1.6.0
[INFO] [stderr]    Compiling memoffset v0.5.1
[INFO] [stderr]     Checking either v1.5.3
[INFO] [stderr]     Checking ansi-escapes v0.1.0
[INFO] [stderr]     Checking crossbeam-queue v0.1.2
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]     Checking crossbeam-epoch v0.7.2
[INFO] [stderr]     Checking crossbeam-deque v0.7.1
[INFO] [stderr]     Checking atty v0.2.13
[INFO] [stderr]     Checking num_cpus v1.10.1
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking rayon v1.2.0
[INFO] [stderr]    Compiling proc-macro-error v0.2.6
[INFO] [stderr]    Compiling structopt-derive v0.3.3
[INFO] [stderr]     Checking structopt v0.3.3
[INFO] [stderr]     Checking sudoku-cli v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/main.rs:15:13
[INFO] [stdout]    |
[INFO] [stdout] 15 |     IOError(std::io::Error),
[INFO] [stdout]    |     ------- ^^^^^^^^^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `SudokuError` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 15 -     IOError(std::io::Error),
[INFO] [stdout] 15 +     IOError(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/main.rs:16:16
[INFO] [stdout]    |
[INFO] [stdout] 16 |     RayonError(rayon::ThreadPoolBuildError),
[INFO] [stdout]    |     ---------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `SudokuError` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 16 -     RayonError(rayon::ThreadPoolBuildError),
[INFO] [stdout] 16 +     RayonError(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/main.rs:48:5
[INFO] [stdout]    |
[INFO] [stdout] 48 | /     /// The path to a puzzle or a puzzle string (for examples: sudoku-cli help)
[INFO] [stdout] 49 | |     #[structopt(short = "i", long = "input")]
[INFO] [stdout] 50 | |     input: String,
[INFO] [stdout]    | |_________________^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/main.rs:56:5
[INFO] [stdout]    |
[INFO] [stdout] 56 | /     /// The path to a file to which the solutions will be written.
[INFO] [stdout] 57 | |     #[structopt(short = "o", long = "output")]
[INFO] [stdout] 58 | |     output: Option<String>,
[INFO] [stdout]    | |__________________________^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/main.rs:67:5
[INFO] [stdout]    |
[INFO] [stdout] 67 | /     /// The path to a puzzle or a puzzle string (for examples: sudoku-cli help)
[INFO] [stdout] 68 | |     #[structopt(short = "i", long = "input")]
[INFO] [stdout] 69 | |     input: String,
[INFO] [stdout]    | |_________________^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/main.rs:78:5
[INFO] [stdout]    |
[INFO] [stdout] 78 | /     /// The path to a puzzle or a puzzle string (for examples: sudoku-cli help)
[INFO] [stdout] 79 | |     #[structopt(short = "i", long = "input")]
[INFO] [stdout] 80 | |     input: String,
[INFO] [stdout]    | |_________________^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `sudoku-cli` (bin "sudoku-cli") due to 4 previous errors; 2 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/main.rs:15:13
[INFO] [stdout]    |
[INFO] [stdout] 15 |     IOError(std::io::Error),
[INFO] [stdout]    |     ------- ^^^^^^^^^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `SudokuError` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 15 -     IOError(std::io::Error),
[INFO] [stdout] 15 +     IOError(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/main.rs:16:16
[INFO] [stdout]    |
[INFO] [stdout] 16 |     RayonError(rayon::ThreadPoolBuildError),
[INFO] [stdout]    |     ---------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `SudokuError` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 16 -     RayonError(rayon::ThreadPoolBuildError),
[INFO] [stdout] 16 +     RayonError(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/main.rs:48:5
[INFO] [stdout]    |
[INFO] [stdout] 48 | /     /// The path to a puzzle or a puzzle string (for examples: sudoku-cli help)
[INFO] [stdout] 49 | |     #[structopt(short = "i", long = "input")]
[INFO] [stdout] 50 | |     input: String,
[INFO] [stdout]    | |_________________^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `sudoku-cli` (bin "sudoku-cli" test) due to 4 previous errors; 2 warnings emitted
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/main.rs:56:5
[INFO] [stdout]    |
[INFO] [stdout] 56 | /     /// The path to a file to which the solutions will be written.
[INFO] [stdout] 57 | |     #[structopt(short = "o", long = "output")]
[INFO] [stdout] 58 | |     output: Option<String>,
[INFO] [stdout]    | |__________________________^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/main.rs:67:5
[INFO] [stdout]    |
[INFO] [stdout] 67 | /     /// The path to a puzzle or a puzzle string (for examples: sudoku-cli help)
[INFO] [stdout] 68 | |     #[structopt(short = "i", long = "input")]
[INFO] [stdout] 69 | |     input: String,
[INFO] [stdout]    | |_________________^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/main.rs:78:5
[INFO] [stdout]    |
[INFO] [stdout] 78 | /     /// The path to a puzzle or a puzzle string (for examples: sudoku-cli help)
[INFO] [stdout] 79 | |     #[structopt(short = "i", long = "input")]
[INFO] [stdout] 80 | |     input: String,
[INFO] [stdout]    | |_________________^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "d19500b62fbd93ddc2f257d4a314abfab88b9e12ee94caa8edc2c798d275e45f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d19500b62fbd93ddc2f257d4a314abfab88b9e12ee94caa8edc2c798d275e45f", kill_on_drop: false }`
[INFO] [stdout] d19500b62fbd93ddc2f257d4a314abfab88b9e12ee94caa8edc2c798d275e45f
