[INFO] cloning repository https://github.com/alxolr/game_2048_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/alxolr/game_2048_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falxolr%2Fgame_2048_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falxolr%2Fgame_2048_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a0b20d70cb4609d6c75b38b9fe18b8abf437b9c8
[INFO] checking alxolr/game_2048_rust against master#90442458ac46b1d5eed752c316da25450f67285b for pr-81477
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falxolr%2Fgame_2048_rust" "/workspace/builds/worker-15/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-15/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/alxolr/game_2048_rust on toolchain 90442458ac46b1d5eed752c316da25450f67285b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/alxolr/game_2048_rust
[INFO] finished tweaking git repo https://github.com/alxolr/game_2048_rust
[INFO] tweaked toml for git repo https://github.com/alxolr/game_2048_rust written to /workspace/builds/worker-15/source/Cargo.toml
[INFO] crate git repo https://github.com/alxolr/game_2048_rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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:ea7d7bff36b2ba8ce4de8bba1d2dea90376bc481f1a945a913994a8c492e40c1" "/opt/rustwide/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8d1a44d40652115aa1caff0e456f8efec8ea1204d920a4533a710cc37b92e6d9
[INFO] running `Command { std: "docker" "start" "-a" "8d1a44d40652115aa1caff0e456f8efec8ea1204d920a4533a710cc37b92e6d9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8d1a44d40652115aa1caff0e456f8efec8ea1204d920a4533a710cc37b92e6d9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8d1a44d40652115aa1caff0e456f8efec8ea1204d920a4533a710cc37b92e6d9", kill_on_drop: false }`
[INFO] [stdout] 8d1a44d40652115aa1caff0e456f8efec8ea1204d920a4533a710cc37b92e6d9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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" "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:ea7d7bff36b2ba8ce4de8bba1d2dea90376bc481f1a945a913994a8c492e40c1" "/opt/rustwide/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] afbaeddf6e3a4f70449641b7cac7fe25536c3c95b2c1d277f0eb5a4e2537b9a9
[INFO] running `Command { std: "docker" "start" "-a" "afbaeddf6e3a4f70449641b7cac7fe25536c3c95b2c1d277f0eb5a4e2537b9a9", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.81
[INFO] [stderr]    Compiling getrandom v0.2.0
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking ppv-lite86 v0.2.10
[INFO] [stderr]     Checking numtoa v0.1.0
[INFO] [stderr]     Checking termion v1.5.5
[INFO] [stderr]     Checking rand_core v0.6.0
[INFO] [stderr]     Checking rand_chacha v0.3.0
[INFO] [stderr]     Checking rand v0.8.0
[INFO] [stderr]     Checking game_2048 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: value assigned to `result` is never read
[INFO] [stdout]    --> src/game.rs:212:17
[INFO] [stdout]     |
[INFO] [stdout] 212 |         let mut result = String::new();
[INFO] [stdout]     |                 ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `result` is never read
[INFO] [stdout]    --> src/game.rs:212:17
[INFO] [stdout]     |
[INFO] [stdout] 212 |         let mut result = String::new();
[INFO] [stdout]     |                 ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[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 [unoptimized + debuginfo] target(s) in 4.74s
[INFO] running `Command { std: "docker" "inspect" "afbaeddf6e3a4f70449641b7cac7fe25536c3c95b2c1d277f0eb5a4e2537b9a9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "afbaeddf6e3a4f70449641b7cac7fe25536c3c95b2c1d277f0eb5a4e2537b9a9", kill_on_drop: false }`
[INFO] [stdout] afbaeddf6e3a4f70449641b7cac7fe25536c3c95b2c1d277f0eb5a4e2537b9a9