[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#ba412a6e70ac84641be7764d088acabd0eb3fa39 for pr-145457
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftestinnplayin%2Frust-exercises" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[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-0-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/testinnplayin/rust-exercises on toolchain ba412a6e70ac84641be7764d088acabd0eb3fa39
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ba412a6e70ac84641be7764d088acabd0eb3fa39" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/testinnplayin/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" "+ba412a6e70ac84641be7764d088acabd0eb3fa39" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+ba412a6e70ac84641be7764d088acabd0eb3fa39" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8b2663fbd93f667e1d981306e1237a61980ef586e8211c1ef828697888d891bf
[INFO] running `Command { std: "docker" "start" "-a" "8b2663fbd93f667e1d981306e1237a61980ef586e8211c1ef828697888d891bf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8b2663fbd93f667e1d981306e1237a61980ef586e8211c1ef828697888d891bf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8b2663fbd93f667e1d981306e1237a61980ef586e8211c1ef828697888d891bf", kill_on_drop: false }`
[INFO] [stdout] 8b2663fbd93f667e1d981306e1237a61980ef586e8211c1ef828697888d891bf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+ba412a6e70ac84641be7764d088acabd0eb3fa39" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b0824c2a4b227847f47521e4a2a631e16227fd68e770bea05b6ac6b0646d6370
[INFO] running `Command { std: "docker" "start" "-a" "b0824c2a4b227847f47521e4a2a631e16227fd68e770bea05b6ac6b0646d6370", kill_on_drop: false }`
[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] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.12s
[INFO] running `Command { std: "docker" "inspect" "b0824c2a4b227847f47521e4a2a631e16227fd68e770bea05b6ac6b0646d6370", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b0824c2a4b227847f47521e4a2a631e16227fd68e770bea05b6ac6b0646d6370", kill_on_drop: false }`
[INFO] [stdout] b0824c2a4b227847f47521e4a2a631e16227fd68e770bea05b6ac6b0646d6370