[INFO] cloning repository https://github.com/branransom/chess
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/branransom/chess" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbranransom%2Fchess", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbranransom%2Fchess'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] bb2c2e725a8fe5fdd3c410192484bfe1507a553a
[INFO] checking branransom/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%2Fbranransom%2Fchess" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/branransom/chess
[INFO] finished tweaking git repo https://github.com/branransom/chess
[INFO] tweaked toml for git repo https://github.com/branransom/chess written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/branransom/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/branransom/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-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] 68bf5ca7ea8c9511f6393b46e2f68af107a730a629f3618d58bd4588d29d5b72
[INFO] running `Command { std: "docker" "start" "-a" "68bf5ca7ea8c9511f6393b46e2f68af107a730a629f3618d58bd4588d29d5b72", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "68bf5ca7ea8c9511f6393b46e2f68af107a730a629f3618d58bd4588d29d5b72", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "68bf5ca7ea8c9511f6393b46e2f68af107a730a629f3618d58bd4588d29d5b72", kill_on_drop: false }`
[INFO] [stdout] 68bf5ca7ea8c9511f6393b46e2f68af107a730a629f3618d58bd4588d29d5b72
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] 87a36b4bb1014d3886d86a731887109e870a2f284c00fa82d34d0d3d88d705a5
[INFO] running `Command { std: "docker" "start" "-a" "87a36b4bb1014d3886d86a731887109e870a2f284c00fa82d34d0d3d88d705a5", kill_on_drop: false }`
[INFO] [stderr]     Checking chess-rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: method `simple_char` is never used
[INFO] [stdout]   --> src/board.rs:14:8
[INFO] [stdout]    |
[INFO] [stdout]  9 | impl Piece {
[INFO] [stdout]    | ---------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 14 |     fn simple_char(&self) -> &'static str {
[INFO] [stdout]    |        ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<usize, Infallible>
[INFO] [stdout]    --> src/board.rs:116:32
[INFO] [stdout]     |
[INFO] [stdout] 116 |         let from_rank: usize = (from / 8).try_into().unwrap();
[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<usize, Infallible>
[INFO] [stdout]    --> src/board.rs:117:32
[INFO] [stdout]     |
[INFO] [stdout] 117 |         let from_file: usize = (from % 8).try_into().unwrap();
[INFO] [stdout]     |                                ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<usize, Infallible>
[INFO] [stdout]    --> src/board.rs:118:30
[INFO] [stdout]     |
[INFO] [stdout] 118 |         let to_rank: usize = (to / 8).try_into().unwrap();
[INFO] [stdout]     |                              ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<usize, Infallible>
[INFO] [stdout]    --> src/board.rs:119:30
[INFO] [stdout]     |
[INFO] [stdout] 119 |         let to_file: usize = (to % 8).try_into().unwrap();
[INFO] [stdout]     |                              ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `chess-rs` (bin "chess-rs" test) due to 4 previous errors; 1 warning emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: method `simple_char` is never used
[INFO] [stdout]   --> src/board.rs:14:8
[INFO] [stdout]    |
[INFO] [stdout]  9 | impl Piece {
[INFO] [stdout]    | ---------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 14 |     fn simple_char(&self) -> &'static str {
[INFO] [stdout]    |        ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<usize, Infallible>
[INFO] [stdout]    --> src/board.rs:116:32
[INFO] [stdout]     |
[INFO] [stdout] 116 |         let from_rank: usize = (from / 8).try_into().unwrap();
[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<usize, Infallible>
[INFO] [stdout]    --> src/board.rs:117:32
[INFO] [stdout]     |
[INFO] [stdout] 117 |         let from_file: usize = (from % 8).try_into().unwrap();
[INFO] [stdout]     |                                ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<usize, Infallible>
[INFO] [stdout]    --> src/board.rs:118:30
[INFO] [stdout]     |
[INFO] [stdout] 118 |         let to_rank: usize = (to / 8).try_into().unwrap();
[INFO] [stdout]     |                              ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<usize, Infallible>
[INFO] [stdout]    --> src/board.rs:119:30
[INFO] [stdout]     |
[INFO] [stdout] 119 |         let to_file: usize = (to % 8).try_into().unwrap();
[INFO] [stdout]     |                              ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `chess-rs` (bin "chess-rs") due to 4 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "87a36b4bb1014d3886d86a731887109e870a2f284c00fa82d34d0d3d88d705a5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "87a36b4bb1014d3886d86a731887109e870a2f284c00fa82d34d0d3d88d705a5", kill_on_drop: false }`
[INFO] [stdout] 87a36b4bb1014d3886d86a731887109e870a2f284c00fa82d34d0d3d88d705a5