[INFO] cloning repository https://github.com/adrienball/2048-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/adrienball/2048-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fadrienball%2F2048-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fadrienball%2F2048-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9e972c43e51b153f66b31a08c37eee140a0d2e57
[INFO] checking adrienball/2048-rs against master#bca37a20bd376ce3fd138e7cdee7fe704e0f8814 for pr-139493-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fadrienball%2F2048-rs" "/workspace/builds/worker-1-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc1/source'...
[INFO] [stderr] done.
[INFO] removed /workspace/builds/worker-1-tc1/source/rust-toolchain
[INFO] started tweaking git repo https://github.com/adrienball/2048-rs
[INFO] finished tweaking git repo https://github.com/adrienball/2048-rs
[INFO] tweaked toml for git repo https://github.com/adrienball/2048-rs written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/adrienball/2048-rs on toolchain bca37a20bd376ce3fd138e7cdee7fe704e0f8814
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+bca37a20bd376ce3fd138e7cdee7fe704e0f8814" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/adrienball/2048-rs 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" "+bca37a20bd376ce3fd138e7cdee7fe704e0f8814" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded regex v1.10.0
[INFO] [stderr]   Downloaded regex-syntax v0.8.0
[INFO] [stderr]   Downloaded regex-automata v0.4.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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:aa71247004a7fa38d13ec170f48f06cdedf5bc50b2a8645e56ed7e992e6fa513" "/opt/rustwide/cargo-home/bin/cargo" "+bca37a20bd376ce3fd138e7cdee7fe704e0f8814" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] bf41e634ad7cf771df8f1107f793934d7d7f4ab57ecae4464d910440fab6497a
[INFO] running `Command { std: "docker" "start" "-a" "bf41e634ad7cf771df8f1107f793934d7d7f4ab57ecae4464d910440fab6497a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "bf41e634ad7cf771df8f1107f793934d7d7f4ab57ecae4464d910440fab6497a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bf41e634ad7cf771df8f1107f793934d7d7f4ab57ecae4464d910440fab6497a", kill_on_drop: false }`
[INFO] [stdout] bf41e634ad7cf771df8f1107f793934d7d7f4ab57ecae4464d910440fab6497a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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:aa71247004a7fa38d13ec170f48f06cdedf5bc50b2a8645e56ed7e992e6fa513" "/opt/rustwide/cargo-home/bin/cargo" "+bca37a20bd376ce3fd138e7cdee7fe704e0f8814" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] acefc7f8367011b3b245c8ad92560c05dbf7cb32fbd8e378eca5274cf36dbeef
[INFO] running `Command { std: "docker" "start" "-a" "acefc7f8367011b3b245c8ad92560c05dbf7cb32fbd8e378eca5274cf36dbeef", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.149
[INFO] [stderr]    Compiling serde v1.0.188
[INFO] [stderr]    Compiling proc-macro2 v1.0.69
[INFO] [stderr]     Checking either v1.9.0
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking regex-syntax v0.8.0
[INFO] [stderr]     Checking memchr v2.6.4
[INFO] [stderr]     Checking plotters-backend v0.3.5
[INFO] [stderr]     Checking numtoa v0.1.0
[INFO] [stderr]     Checking cast v0.3.0
[INFO] [stderr]     Checking walkdir v2.4.0
[INFO] [stderr]     Checking itertools v0.10.5
[INFO] [stderr]     Checking rayon v1.8.0
[INFO] [stderr]     Checking csv-core v0.1.11
[INFO] [stderr]     Checking plotters-svg v0.3.5
[INFO] [stderr]    Compiling quote v1.0.33
[INFO] [stderr]     Checking plotters v0.3.5
[INFO] [stderr]     Checking getrandom v0.1.16
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking termion v1.5.6
[INFO] [stderr]     Checking clap v2.34.0
[INFO] [stderr]    Compiling syn v2.0.38
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking regex-automata v0.4.1
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking play-2048 v1.0.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking criterion-plot v0.4.5
[INFO] [stderr]     Checking regex v1.10.0
[INFO] [stderr]     Checking serde_json v1.0.107
[INFO] [stderr]     Checking serde_cbor v0.11.2
[INFO] [stderr]     Checking csv v1.3.0
[INFO] [stderr]     Checking tinytemplate v1.2.1
[INFO] [stderr]    Compiling serde_derive v1.0.188
[INFO] [stderr]     Checking criterion v0.3.6
[INFO] [stdout] warning: unused return value of `must_use` that must be used
[INFO] [stdout]    --> src/board.rs:830:9
[INFO] [stdout]     |
[INFO] [stdout] 830 |         format!("{}", board);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 830 |         let _ = format!("{}", board);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `must_use` that must be used
[INFO] [stdout]    --> src/board.rs:830:9
[INFO] [stdout]     |
[INFO] [stdout] 830 |         format!("{}", board);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 830 |         let _ = format!("{}", board);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 17.94s
[INFO] running `Command { std: "docker" "inspect" "acefc7f8367011b3b245c8ad92560c05dbf7cb32fbd8e378eca5274cf36dbeef", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "acefc7f8367011b3b245c8ad92560c05dbf7cb32fbd8e378eca5274cf36dbeef", kill_on_drop: false }`
[INFO] [stdout] acefc7f8367011b3b245c8ad92560c05dbf7cb32fbd8e378eca5274cf36dbeef
