[INFO] cloning repository https://github.com/tvallotton/chess
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tvallotton/chess" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftvallotton%2Fchess", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftvallotton%2Fchess'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 98b01208e95173388cf4f781cc83bb414bb3bf55
[INFO] checking tvallotton/chess against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftvallotton%2Fchess" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/tvallotton/chess
[INFO] finished tweaking git repo https://github.com/tvallotton/chess
[INFO] tweaked toml for git repo https://github.com/tvallotton/chess written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/tvallotton/chess 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 git repo https://github.com/tvallotton/chess 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-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0875cfd658ea37322d4573839a04558a23bcde298981de136b8334b51d96c9be
[INFO] running `Command { std: "docker" "start" "-a" "0875cfd658ea37322d4573839a04558a23bcde298981de136b8334b51d96c9be", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0875cfd658ea37322d4573839a04558a23bcde298981de136b8334b51d96c9be", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0875cfd658ea37322d4573839a04558a23bcde298981de136b8334b51d96c9be", kill_on_drop: false }`
[INFO] [stdout] 0875cfd658ea37322d4573839a04558a23bcde298981de136b8334b51d96c9be
[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 -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] 19533bcacff84eb595a507f102891be38e8afcef1667c533da10d9e312cdb5fa
[INFO] running `Command { std: "docker" "start" "-a" "19533bcacff84eb595a507f102891be38e8afcef1667c533da10d9e312cdb5fa", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.37
[INFO] [stderr]    Compiling syn v1.0.91
[INFO] [stderr]    Compiling libc v0.2.124
[INFO] [stderr]    Compiling serde_derive v1.0.136
[INFO] [stderr]    Compiling serde v1.0.136
[INFO] [stderr]    Compiling serde_json v1.0.79
[INFO] [stderr]     Checking ryu v1.0.9
[INFO] [stderr]     Checking itoa v1.0.1
[INFO] [stderr]     Checking smallvec v1.8.0
[INFO] [stderr]     Checking tinyvec v1.5.1
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking clap v2.34.0
[INFO] [stderr]    Compiling quote v1.0.18
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling structopt-derive v0.4.18
[INFO] [stderr]     Checking structopt v0.3.26
[INFO] [stderr]     Checking chess v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::collections::BinaryHeap`
[INFO] [stdout]  --> src/minimax.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::collections::BinaryHeap;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Color::*`
[INFO] [stdout]  --> src/minimax.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use Color::*;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::default`
[INFO] [stdout]  --> src/opt.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::default;
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Color::*`
[INFO] [stdout]  --> src/start_board.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use Color::*;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Kind::*`
[INFO] [stdout]  --> src/start_board.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use Kind::*;
[INFO] [stdout]   |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::settings::*`
[INFO] [stdout]  --> src/table.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use crate::settings::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::BinaryHeap`
[INFO] [stdout]  --> src/minimax.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::collections::BinaryHeap;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Color::*`
[INFO] [stdout]  --> src/minimax.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use Color::*;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::default`
[INFO] [stdout]  --> src/opt.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::default;
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Color::*`
[INFO] [stdout]  --> src/start_board.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use Color::*;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Kind::*`
[INFO] [stdout]  --> src/start_board.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use Kind::*;
[INFO] [stdout]   |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::settings::*`
[INFO] [stdout]  --> src/table.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use crate::settings::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `rough_estimate`
[INFO] [stdout]   --> src/minimax.rs:77:13
[INFO] [stdout]    |
[INFO] [stdout] 77 |         let rough_estimate = player_score - opponent_score;
[INFO] [stdout]    |             ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_rough_estimate`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `rough_estimate`
[INFO] [stdout]   --> src/minimax.rs:77:13
[INFO] [stdout]    |
[INFO] [stdout] 77 |         let rough_estimate = player_score - opponent_score;
[INFO] [stdout]    |             ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_rough_estimate`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `options`
[INFO] [stdout]   --> src/main.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let options = opt::Opt::from_args();
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_options`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<std::string::String, Infallible>
[INFO] [stdout]   --> src/opt.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | /     #[structopt(short = "s", long, default_value = "./settings.json")]
[INFO] [stdout] 14 | |     pub settings_path: 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] warning: unused variable: `options`
[INFO] [stdout]   --> src/main.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let options = opt::Opt::from_args();
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_options`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<std::string::String, Infallible>
[INFO] [stdout]   --> src/opt.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | /     #[structopt(short = "s", long, default_value = "./settings.json")]
[INFO] [stdout] 14 | |     pub settings_path: 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 `chess` (bin "chess") due to 1 previous error; 8 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `chess` (bin "chess" test) due to 1 previous error; 8 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "19533bcacff84eb595a507f102891be38e8afcef1667c533da10d9e312cdb5fa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "19533bcacff84eb595a507f102891be38e8afcef1667c533da10d9e312cdb5fa", kill_on_drop: false }`
[INFO] [stdout] 19533bcacff84eb595a507f102891be38e8afcef1667c533da10d9e312cdb5fa