[INFO] cloning repository https://github.com/ddavison/rust-exercises
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ddavison/rust-exercises" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fddavison%2Frust-exercises", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fddavison%2Frust-exercises'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] bd2c076cacf37fa15e38ff5bdd6aa871d161b343
[INFO] checking ddavison/rust-exercises against master#f7b43542838f0a4a6cfdb17fbeadf45002042a77 for pr-138499
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fddavison%2Frust-exercises" "/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/ddavison/rust-exercises on toolchain f7b43542838f0a4a6cfdb17fbeadf45002042a77
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+f7b43542838f0a4a6cfdb17fbeadf45002042a77" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ddavison/rust-exercises
[INFO] finished tweaking git repo https://github.com/ddavison/rust-exercises
[INFO] tweaked toml for git repo https://github.com/ddavison/rust-exercises written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/ddavison/rust-exercises 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" "+f7b43542838f0a4a6cfdb17fbeadf45002042a77" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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@sha256:1680c8fbd8dfb46fcd6d22e546df16ab0e007457dc29fcd9e987cdd5077fd1af" "/opt/rustwide/cargo-home/bin/cargo" "+f7b43542838f0a4a6cfdb17fbeadf45002042a77" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 331f966c41a05f80404b61e0a789f5bb0102df8e5347bb5037d3af33c21d8420
[INFO] running `Command { std: "docker" "start" "-a" "331f966c41a05f80404b61e0a789f5bb0102df8e5347bb5037d3af33c21d8420", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "331f966c41a05f80404b61e0a789f5bb0102df8e5347bb5037d3af33c21d8420", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "331f966c41a05f80404b61e0a789f5bb0102df8e5347bb5037d3af33c21d8420", kill_on_drop: false }`
[INFO] [stdout] 331f966c41a05f80404b61e0a789f5bb0102df8e5347bb5037d3af33c21d8420
[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@sha256:1680c8fbd8dfb46fcd6d22e546df16ab0e007457dc29fcd9e987cdd5077fd1af" "/opt/rustwide/cargo-home/bin/cargo" "+f7b43542838f0a4a6cfdb17fbeadf45002042a77" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 63f3b9990cbef9edcce3de2af426ad749835034395257cb8d887312cbbac515f
[INFO] running `Command { std: "docker" "start" "-a" "63f3b9990cbef9edcce3de2af426ad749835034395257cb8d887312cbbac515f", kill_on_drop: false }`
[INFO] [stderr]     Checking exercises v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]  --> src/main.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let b = true;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]  --> src/main.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let b = true;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.08s
[INFO] running `Command { std: "docker" "inspect" "63f3b9990cbef9edcce3de2af426ad749835034395257cb8d887312cbbac515f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "63f3b9990cbef9edcce3de2af426ad749835034395257cb8d887312cbbac515f", kill_on_drop: false }`
[INFO] [stdout] 63f3b9990cbef9edcce3de2af426ad749835034395257cb8d887312cbbac515f