[INFO] fetching crate chess-rs 0.1.0...
[INFO] checking chess-rs-0.1.0 against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] extracting crate chess-rs 0.1.0 into /workspace/builds/worker-3-tc1/source
[INFO] validating manifest of crates.io crate chess-rs 0.1.0 on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate chess-rs 0.1.0
[INFO] finished tweaking crates.io crate chess-rs 0.1.0
[INFO] tweaked toml for crates.io crate chess-rs 0.1.0 written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 10 packages
[INFO] [stderr]       Adding ansi_term v0.9.0 (latest: v0.12.1)
[INFO] [stderr]       Adding bitflags v1.3.2 (latest: v2.5.0)
[INFO] [stderr]       Adding matrix_display v0.4.1 (latest: v1.0.0)
[INFO] [stderr]       Adding numtoa v0.1.0 (latest: v0.2.4)
[INFO] [stderr]       Adding redox_syscall v0.2.16 (latest: v0.5.1)
[INFO] [stderr]       Adding termion v1.5.6 (latest: v3.0.0)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded ansi_term v0.9.0
[INFO] [stderr]   Downloaded matrix_display v0.4.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 37da7db07f521935bdc89f0342530ecf0e8a775bd27a710246b73ec5b879e810
[INFO] running `Command { std: "docker" "start" "-a" "37da7db07f521935bdc89f0342530ecf0e8a775bd27a710246b73ec5b879e810", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "37da7db07f521935bdc89f0342530ecf0e8a775bd27a710246b73ec5b879e810", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "37da7db07f521935bdc89f0342530ecf0e8a775bd27a710246b73ec5b879e810", kill_on_drop: false }`
[INFO] [stdout] 37da7db07f521935bdc89f0342530ecf0e8a775bd27a710246b73ec5b879e810
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5a79a10a94d0cf84a2f2a553a44feadc57026601a574b66a937cd61899f475ad
[INFO] running `Command { std: "docker" "start" "-a" "5a79a10a94d0cf84a2f2a553a44feadc57026601a574b66a937cd61899f475ad", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.153
[INFO] [stderr]     Checking numtoa v0.1.0
[INFO] [stderr]     Checking unicode-segmentation v1.11.0
[INFO] [stderr]     Checking ansi_term v0.9.0
[INFO] [stderr]     Checking matrix_display v0.4.1
[INFO] [stderr]     Checking termion v1.5.6
[INFO] [stderr]     Checking chess-rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:38:33
[INFO] [stdout]    |
[INFO] [stdout] 38 | ...                   let mut cell =
[INFO] [stdout]    |                           ----^^^^
[INFO] [stdout]    |                           |
[INFO] [stdout]    |                           help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:38:33
[INFO] [stdout]    |
[INFO] [stdout] 38 | ...                   let mut cell =
[INFO] [stdout]    |                           ----^^^^
[INFO] [stdout]    |                           |
[INFO] [stdout]    |                           help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.86s
[INFO] running `Command { std: "docker" "inspect" "5a79a10a94d0cf84a2f2a553a44feadc57026601a574b66a937cd61899f475ad", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5a79a10a94d0cf84a2f2a553a44feadc57026601a574b66a937cd61899f475ad", kill_on_drop: false }`
[INFO] [stdout] 5a79a10a94d0cf84a2f2a553a44feadc57026601a574b66a937cd61899f475ad
[INFO] checking chess-rs-0.1.0 against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] extracting crate chess-rs 0.1.0 into /workspace/builds/worker-3-tc2/source
[INFO] validating manifest of crates.io crate chess-rs 0.1.0 on toolchain 2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate chess-rs 0.1.0
[INFO] finished tweaking crates.io crate chess-rs 0.1.0
[INFO] tweaked toml for crates.io crate chess-rs 0.1.0 written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 10 packages
[INFO] [stderr]       Adding ansi_term v0.9.0 (latest: v0.12.1)
[INFO] [stderr]       Adding bitflags v1.3.2 (latest: v2.5.0)
[INFO] [stderr]       Adding matrix_display v0.4.1 (latest: v1.0.0)
[INFO] [stderr]       Adding numtoa v0.1.0 (latest: v0.2.4)
[INFO] [stderr]       Adding redox_syscall v0.2.16 (latest: v0.5.1)
[INFO] [stderr]       Adding termion v1.5.6 (latest: v3.0.0)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b4793f53ff478170a0809765fc927ced9b233f3665505a445897143c5fd88a9a
[INFO] running `Command { std: "docker" "start" "-a" "b4793f53ff478170a0809765fc927ced9b233f3665505a445897143c5fd88a9a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b4793f53ff478170a0809765fc927ced9b233f3665505a445897143c5fd88a9a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b4793f53ff478170a0809765fc927ced9b233f3665505a445897143c5fd88a9a", kill_on_drop: false }`
[INFO] [stdout] b4793f53ff478170a0809765fc927ced9b233f3665505a445897143c5fd88a9a
[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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 579541ac420f7edb4b4136e5a26f0fc1ae9126ddbd4258b45ea932c39037c1af
[INFO] running `Command { std: "docker" "start" "-a" "579541ac420f7edb4b4136e5a26f0fc1ae9126ddbd4258b45ea932c39037c1af", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.153
[INFO] [stderr]     Checking unicode-segmentation v1.11.0
[INFO] [stderr]     Checking numtoa v0.1.0
[INFO] [stderr]     Checking ansi_term v0.9.0
[INFO] [stderr]     Checking matrix_display v0.4.1
[INFO] [stderr]     Checking termion v1.5.6
[INFO] [stderr]     Checking chess-rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:38:33
[INFO] [stdout]    |
[INFO] [stdout] 38 | ...                   let mut cell =
[INFO] [stdout]    |                           ----^^^^
[INFO] [stdout]    |                           |
[INFO] [stdout]    |                           help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:38:33
[INFO] [stdout]    |
[INFO] [stdout] 38 | ...                   let mut cell =
[INFO] [stdout]    |                           ----^^^^
[INFO] [stdout]    |                           |
[INFO] [stdout]    |                           help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.96s
[INFO] running `Command { std: "docker" "inspect" "579541ac420f7edb4b4136e5a26f0fc1ae9126ddbd4258b45ea932c39037c1af", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "579541ac420f7edb4b4136e5a26f0fc1ae9126ddbd4258b45ea932c39037c1af", kill_on_drop: false }`
[INFO] [stdout] 579541ac420f7edb4b4136e5a26f0fc1ae9126ddbd4258b45ea932c39037c1af