[INFO] cloning repository https://github.com/plorefice/b2048
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/plorefice/b2048" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fplorefice%2Fb2048", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fplorefice%2Fb2048'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7c0b69071e81abb9bdb12a77ab73f33af61b8576
[INFO] checking plorefice/b2048 against master#00bfd6b2734d9c28a147bf237490995731781fdd for pr-117984
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fplorefice%2Fb2048" "/workspace/builds/worker-3-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/plorefice/b2048 on toolchain 00bfd6b2734d9c28a147bf237490995731781fdd
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+00bfd6b2734d9c28a147bf237490995731781fdd" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/plorefice/b2048
[INFO] finished tweaking git repo https://github.com/plorefice/b2048
[INFO] tweaked toml for git repo https://github.com/plorefice/b2048 written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/plorefice/b2048 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" "+00bfd6b2734d9c28a147bf237490995731781fdd" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded rand v0.3.20
[INFO] [stderr]   Downloaded num-rational v0.1.41
[INFO] [stderr]   Downloaded ncurses v5.91.0
[INFO] [stderr]   Downloaded num-bigint v0.1.41
[INFO] [stderr]   Downloaded cursive v0.7.5
[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" "+00bfd6b2734d9c28a147bf237490995731781fdd" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3d004c41d0fbed49480b0bdfa49d3740840d6eb52b83b97fd38ab01d1d02aac6
[INFO] running `Command { std: "docker" "start" "-a" "3d004c41d0fbed49480b0bdfa49d3740840d6eb52b83b97fd38ab01d1d02aac6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3d004c41d0fbed49480b0bdfa49d3740840d6eb52b83b97fd38ab01d1d02aac6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3d004c41d0fbed49480b0bdfa49d3740840d6eb52b83b97fd38ab01d1d02aac6", kill_on_drop: false }`
[INFO] [stdout] 3d004c41d0fbed49480b0bdfa49d3740840d6eb52b83b97fd38ab01d1d02aac6
[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" "+00bfd6b2734d9c28a147bf237490995731781fdd" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 57873891c3b1ffe635f22d5fda7b096e15c020e9e120b687d59d3267836844ed
[INFO] running `Command { std: "docker" "start" "-a" "57873891c3b1ffe635f22d5fda7b096e15c020e9e120b687d59d3267836844ed", kill_on_drop: false }`
[INFO] [stderr]     Checking num-traits v0.1.42
[INFO] [stderr]     Checking libc v0.2.36
[INFO] [stderr]     Checking rustc-serialize v0.3.24
[INFO] [stderr]    Compiling gcc v0.3.54
[INFO] [stderr]    Compiling pkg-config v0.3.9
[INFO] [stderr]     Checking cfg-if v0.1.2
[INFO] [stderr]     Checking serde v1.0.27
[INFO] [stderr]     Checking stable_deref_trait v1.0.0
[INFO] [stderr]     Checking log v0.4.1
[INFO] [stderr]     Checking owning_ref v0.3.3
[INFO] [stderr]     Checking log v0.3.9
[INFO] [stderr]     Checking unicode-segmentation v1.2.0
[INFO] [stderr]     Checking unicode-width v0.1.4
[INFO] [stderr]     Checking maplit v1.0.1
[INFO] [stderr]     Checking rand v0.3.20
[INFO] [stderr]     Checking num-integer v0.1.35
[INFO] [stderr]    Compiling ncurses v5.91.0
[INFO] [stderr]     Checking num-iter v0.1.34
[INFO] [stderr]     Checking num-bigint v0.1.41
[INFO] [stderr]     Checking num-complex v0.1.41
[INFO] [stderr]     Checking num-rational v0.1.41
[INFO] [stderr]     Checking num v0.1.41
[INFO] [stderr]     Checking toml v0.4.5
[INFO] [stderr]     Checking cursive v0.7.5
[INFO] [stderr]     Checking b2048 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the feature `conservative_impl_trait` has been stable since 1.26.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/main.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(conservative_impl_trait)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `conservative_impl_trait` has been stable since 1.26.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/main.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(conservative_impl_trait)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `score` is never read
[INFO] [stdout]   --> src/board.rs:26:5
[INFO] [stdout]    |
[INFO] [stdout] 24 | pub struct Board {
[INFO] [stdout]    |            ----- field in this struct
[INFO] [stdout] 25 |     tiles: Vec<Vec<u32>>,
[INFO] [stdout] 26 |     score: u32,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Board` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `score` is never read
[INFO] [stdout]   --> src/board.rs:26:5
[INFO] [stdout]    |
[INFO] [stdout] 24 | pub struct Board {
[INFO] [stdout]    |            ----- field in this struct
[INFO] [stdout] 25 |     tiles: Vec<Vec<u32>>,
[INFO] [stdout] 26 |     score: u32,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Board` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.44s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: rustc-serialize v0.3.24
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 2`
[INFO] running `Command { std: "docker" "inspect" "57873891c3b1ffe635f22d5fda7b096e15c020e9e120b687d59d3267836844ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "57873891c3b1ffe635f22d5fda7b096e15c020e9e120b687d59d3267836844ed", kill_on_drop: false }`
[INFO] [stdout] 57873891c3b1ffe635f22d5fda7b096e15c020e9e120b687d59d3267836844ed