[INFO] cloning repository https://github.com/ram4ik/rust_app
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ram4ik/rust_app" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fram4ik%2Frust_app", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fram4ik%2Frust_app'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f7c9b99ba140c9831745f4d28b8301953df80bf8
[INFO] checking ram4ik/rust_app against master#f21fbac535ab2c3bc50db20547f4d48477357103 for pr-143193
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fram4ik%2Frust_app" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/ram4ik/rust_app
[INFO] finished tweaking git repo https://github.com/ram4ik/rust_app
[INFO] tweaked toml for git repo https://github.com/ram4ik/rust_app written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/ram4ik/rust_app on toolchain f21fbac535ab2c3bc50db20547f4d48477357103
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+f21fbac535ab2c3bc50db20547f4d48477357103" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/ram4ik/rust_app 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" "+f21fbac535ab2c3bc50db20547f4d48477357103" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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:cf8efcab8866f2cf4285301c7418e2f4f2a9b088c91ba69c40d5b659f81557f7" "/opt/rustwide/cargo-home/bin/cargo" "+f21fbac535ab2c3bc50db20547f4d48477357103" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e4118537da152759f64e5a58d276724c5fe2cc470509a8fb390e0d10ef909bf1
[INFO] running `Command { std: "docker" "start" "-a" "e4118537da152759f64e5a58d276724c5fe2cc470509a8fb390e0d10ef909bf1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e4118537da152759f64e5a58d276724c5fe2cc470509a8fb390e0d10ef909bf1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e4118537da152759f64e5a58d276724c5fe2cc470509a8fb390e0d10ef909bf1", kill_on_drop: false }`
[INFO] [stdout] e4118537da152759f64e5a58d276724c5fe2cc470509a8fb390e0d10ef909bf1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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:cf8efcab8866f2cf4285301c7418e2f4f2a9b088c91ba69c40d5b659f81557f7" "/opt/rustwide/cargo-home/bin/cargo" "+f21fbac535ab2c3bc50db20547f4d48477357103" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c3fb71b25540085d294c73b24b0778c9165f6085c48a533c65b77474dc92613e
[INFO] running `Command { std: "docker" "start" "-a" "c3fb71b25540085d294c73b24b0778c9165f6085c48a533c65b77474dc92613e", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_app v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `must_use` that must be used
[INFO] [stdout]   --> src/main.rs:17:5
[INFO] [stdout]    |
[INFO] [stdout] 17 |     format!("{} is highest", b);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let _ = format!("{} is highest", b);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `must_use` that must be used
[INFO] [stdout]   --> src/main.rs:17:5
[INFO] [stdout]    |
[INFO] [stdout] 17 |     format!("{} is highest", b);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let _ = format!("{} is highest", b);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.12s
[INFO] running `Command { std: "docker" "inspect" "c3fb71b25540085d294c73b24b0778c9165f6085c48a533c65b77474dc92613e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c3fb71b25540085d294c73b24b0778c9165f6085c48a533c65b77474dc92613e", kill_on_drop: false }`
[INFO] [stdout] c3fb71b25540085d294c73b24b0778c9165f6085c48a533c65b77474dc92613e