[INFO] cloning repository https://github.com/MaxRong/Rustoku
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/MaxRong/Rustoku" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMaxRong%2FRustoku", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMaxRong%2FRustoku'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b95c08256b59cc97a99cfdd212263ab51d466e20
[INFO] checking MaxRong/Rustoku against try#81ab7f2139295590561adbe6d5b0aaa2feff765f for pr-146470-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMaxRong%2FRustoku" "/workspace/builds/worker-3-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/MaxRong/Rustoku
[INFO] finished tweaking git repo https://github.com/MaxRong/Rustoku
[INFO] tweaked toml for git repo https://github.com/MaxRong/Rustoku written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/MaxRong/Rustoku on toolchain 81ab7f2139295590561adbe6d5b0aaa2feff765f
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+81ab7f2139295590561adbe6d5b0aaa2feff765f" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/MaxRong/Rustoku 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" "+81ab7f2139295590561adbe6d5b0aaa2feff765f" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[INFO] checking MaxRong/Rustoku against try#81ab7f2139295590561adbe6d5b0aaa2feff765f for pr-146470-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMaxRong%2FRustoku" "/workspace/builds/worker-3-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/MaxRong/Rustoku
[INFO] finished tweaking git repo https://github.com/MaxRong/Rustoku
[INFO] tweaked toml for git repo https://github.com/MaxRong/Rustoku written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/MaxRong/Rustoku on toolchain 81ab7f2139295590561adbe6d5b0aaa2feff765f
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+81ab7f2139295590561adbe6d5b0aaa2feff765f" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/MaxRong/Rustoku 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" "+81ab7f2139295590561adbe6d5b0aaa2feff765f" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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@sha256:845e597a41426bbf2703be69acdb67d10b6de511142d05cba7bbe119c898b2c7" "/opt/rustwide/cargo-home/bin/cargo" "+81ab7f2139295590561adbe6d5b0aaa2feff765f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c9920fce80d7009c4e3ce27607090d5e20c558eed7c1756aed87beb7827e9e5d
[INFO] running `Command { std: "docker" "start" "-a" "c9920fce80d7009c4e3ce27607090d5e20c558eed7c1756aed87beb7827e9e5d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c9920fce80d7009c4e3ce27607090d5e20c558eed7c1756aed87beb7827e9e5d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c9920fce80d7009c4e3ce27607090d5e20c558eed7c1756aed87beb7827e9e5d", kill_on_drop: false }`
[INFO] [stdout] c9920fce80d7009c4e3ce27607090d5e20c558eed7c1756aed87beb7827e9e5d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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@sha256:845e597a41426bbf2703be69acdb67d10b6de511142d05cba7bbe119c898b2c7" "/opt/rustwide/cargo-home/bin/cargo" "+81ab7f2139295590561adbe6d5b0aaa2feff765f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 439fb2c56c6d2fb9a895262ea34759a7a67c61a02bd2cd051350b1431b6c1fa9
[INFO] running `Command { std: "docker" "start" "-a" "439fb2c56c6d2fb9a895262ea34759a7a67c61a02bd2cd051350b1431b6c1fa9", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_sudoku v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let mut board: SudokuBoard = SudokuBoard::from(config).expect("Build failed"); // will panic if config is invalid.
[INFO] [stdout]    |         ----^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let mut solved_board = BacktrackingSolver::run(&board).unwrap();
[INFO] [stdout]    |         ----^^^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `initial_mask` is never read
[INFO] [stdout]  --> src/sudoku_board.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub struct SudokuBoard {
[INFO] [stdout]   |            ----------- field in this struct
[INFO] [stdout] 6 |     board: [[u8; 9]; 9],
[INFO] [stdout] 7 |     initial_mask: [[bool; 9]; 9],
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `SudokuBoard` has a derived impl for the trait `Clone`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `get_board` and `try_place` are never used
[INFO] [stdout]   --> src/sudoku_board.rs:43:12
[INFO] [stdout]    |
[INFO] [stdout] 10 | impl SudokuBoard {
[INFO] [stdout]    | ---------------- methods in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 43 |     pub fn get_board(&self) -> &[[u8; 9]; 9] {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 47 |     pub fn try_place(&mut self, cell: (u8, u8), num: u8) -> Result<(), &'static str> {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let mut board: SudokuBoard = SudokuBoard::from(config).expect("Build failed"); // will panic if config is invalid.
[INFO] [stdout]    |         ----^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let mut solved_board = BacktrackingSolver::run(&board).unwrap();
[INFO] [stdout]    |         ----^^^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `get_board` is never used
[INFO] [stdout]   --> src/sudoku_board.rs:43:12
[INFO] [stdout]    |
[INFO] [stdout] 10 | impl SudokuBoard {
[INFO] [stdout]    | ---------------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 43 |     pub fn get_board(&self) -> &[[u8; 9]; 9] {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/sudoku_board.rs:284:9
[INFO] [stdout]     |
[INFO] [stdout] 284 |         board.try_place((0, 0), 3);
[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)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 284 |         let _ = board.try_place((0, 0), 3);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/sudoku_board.rs:287:9
[INFO] [stdout]     |
[INFO] [stdout] 287 |         board.try_place((0, 0), 0); // clear placed number from previous test.
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 287 |         let _ = board.try_place((0, 0), 0); // clear placed number from previous test.
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.08s
[INFO] running `Command { std: "docker" "inspect" "439fb2c56c6d2fb9a895262ea34759a7a67c61a02bd2cd051350b1431b6c1fa9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "439fb2c56c6d2fb9a895262ea34759a7a67c61a02bd2cd051350b1431b6c1fa9", kill_on_drop: false }`
[INFO] [stdout] 439fb2c56c6d2fb9a895262ea34759a7a67c61a02bd2cd051350b1431b6c1fa9
