[INFO] cloning repository https://github.com/testinnplayin/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/testinnplayin/rust-exercises" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftestinnplayin%2Frust-exercises", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftestinnplayin%2Frust-exercises'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a8720b3bc233f7ada3f429aeea9d68a21d803a6f
[INFO] checking testinnplayin/rust-exercises against master#89b9f7b284aacc5f8613438b80e4dd7bdd10549e for pr-92594
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftestinnplayin%2Frust-exercises" "/workspace/builds/worker-60/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-60/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/testinnplayin/rust-exercises on toolchain 89b9f7b284aacc5f8613438b80e4dd7bdd10549e
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+89b9f7b284aacc5f8613438b80e4dd7bdd10549e" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/testinnplayin/rust-exercises
[INFO] finished tweaking git repo https://github.com/testinnplayin/rust-exercises
[INFO] tweaked toml for git repo https://github.com/testinnplayin/rust-exercises written to /workspace/builds/worker-60/source/Cargo.toml
[INFO] crate git repo https://github.com/testinnplayin/rust-exercises already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+89b9f7b284aacc5f8613438b80e4dd7bdd10549e" "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-60/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-60/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+89b9f7b284aacc5f8613438b80e4dd7bdd10549e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 88bed919d42133bbaf5e9bdfee552bdf4ab8078315dcb7a3567b3cf2e5e72280
[INFO] running `Command { std: "docker" "start" "-a" "88bed919d42133bbaf5e9bdfee552bdf4ab8078315dcb7a3567b3cf2e5e72280", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "88bed919d42133bbaf5e9bdfee552bdf4ab8078315dcb7a3567b3cf2e5e72280", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "88bed919d42133bbaf5e9bdfee552bdf4ab8078315dcb7a3567b3cf2e5e72280", kill_on_drop: false }`
[INFO] [stdout] 88bed919d42133bbaf5e9bdfee552bdf4ab8078315dcb7a3567b3cf2e5e72280
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-60/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-60/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+89b9f7b284aacc5f8613438b80e4dd7bdd10549e" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 977ed14c9fc4e498e9cd8f695dad5e1b6afc132f17f520ba1107002f7e8cd5ec
[INFO] running `Command { std: "docker" "start" "-a" "977ed14c9fc4e498e9cd8f695dad5e1b6afc132f17f520ba1107002f7e8cd5ec", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking chapter-8-exercises v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/statistics_module.rs:21:5
[INFO] [stdout]    |
[INFO] [stdout] 21 |     &vec_of_nums.sort();
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[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] 21 |     let _ = &vec_of_nums.sort();
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/statistics_module.rs:21:5
[INFO] [stdout]    |
[INFO] [stdout] 21 |     &vec_of_nums.sort();
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[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] 21 |     let _ = &vec_of_nums.sort();
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 9.89s
[INFO] running `Command { std: "docker" "inspect" "977ed14c9fc4e498e9cd8f695dad5e1b6afc132f17f520ba1107002f7e8cd5ec", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "977ed14c9fc4e498e9cd8f695dad5e1b6afc132f17f520ba1107002f7e8cd5ec", kill_on_drop: false }`
[INFO] [stdout] 977ed14c9fc4e498e9cd8f695dad5e1b6afc132f17f520ba1107002f7e8cd5ec