[INFO] cloning repository https://github.com/steelsoul/txt2048
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/steelsoul/txt2048" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsteelsoul%2Ftxt2048", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsteelsoul%2Ftxt2048'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] bdb57c2d2c6750ea1084a6f76ae5dc85d921c47b
[INFO] checking steelsoul/txt2048 against beta for pr-78714
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsteelsoul%2Ftxt2048" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/steelsoul/txt2048 on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/steelsoul/txt2048
[INFO] finished tweaking git repo https://github.com/steelsoul/txt2048
[INFO] tweaked toml for git repo https://github.com/steelsoul/txt2048 written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/steelsoul/txt2048 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] e8953dad2d2380f20f8d89945fa3cf58564daf4e8ceb6c66d4ce527dce2e62a2
[INFO] running `Command { std: "docker" "start" "-a" "e8953dad2d2380f20f8d89945fa3cf58564daf4e8ceb6c66d4ce527dce2e62a2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e8953dad2d2380f20f8d89945fa3cf58564daf4e8ceb6c66d4ce527dce2e62a2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e8953dad2d2380f20f8d89945fa3cf58564daf4e8ceb6c66d4ce527dce2e62a2", kill_on_drop: false }`
[INFO] [stdout] e8953dad2d2380f20f8d89945fa3cf58564daf4e8ceb6c66d4ce527dce2e62a2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 7aa9e8dac16d033d136a883c3af6b4f9734481aa346f0ed03f8387729283e5ba
[INFO] running `Command { std: "docker" "start" "-a" "7aa9e8dac16d033d136a883c3af6b4f9734481aa346f0ed03f8387729283e5ba", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.76
[INFO] [stderr]     Checking getrandom v0.1.14
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking txt2048 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: associated function is never used: `get_index`
[INFO] [stdout]   --> src/main.rs:91:8
[INFO] [stdout]    |
[INFO] [stdout] 91 |     fn get_index(&self, pos: (u32, u32)) -> usize {
[INFO] [stdout]    |        ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/main.rs:67:13
[INFO] [stdout]    |
[INFO] [stdout] 67 |             io::stdout().flush();
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/main.rs:67:13
[INFO] [stdout]    |
[INFO] [stdout] 67 |             io::stdout().flush();
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.70s
[INFO] running `Command { std: "docker" "inspect" "7aa9e8dac16d033d136a883c3af6b4f9734481aa346f0ed03f8387729283e5ba", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7aa9e8dac16d033d136a883c3af6b4f9734481aa346f0ed03f8387729283e5ba", kill_on_drop: false }`
[INFO] [stdout] 7aa9e8dac16d033d136a883c3af6b4f9734481aa346f0ed03f8387729283e5ba