[INFO] fetching crate briliang_exercise 0.1.0...
[INFO] checking briliang_exercise-0.1.0 against master#8007b506ac5da629f223b755f5a5391edd5f6d01 for pr-88041
[INFO] extracting crate briliang_exercise 0.1.0 into /workspace/builds/worker-25/source
[INFO] validating manifest of crates.io crate briliang_exercise 0.1.0 on toolchain 8007b506ac5da629f223b755f5a5391edd5f6d01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate briliang_exercise 0.1.0
[INFO] finished tweaking crates.io crate briliang_exercise 0.1.0
[INFO] tweaked toml for crates.io crate briliang_exercise 0.1.0 written to /workspace/builds/worker-25/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "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-25/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-25/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 03c47e07ba81ea728922ed3aea605f525064d6337c16e25998b3b4db8e54fc34
[INFO] running `Command { std: "docker" "start" "-a" "03c47e07ba81ea728922ed3aea605f525064d6337c16e25998b3b4db8e54fc34", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "03c47e07ba81ea728922ed3aea605f525064d6337c16e25998b3b4db8e54fc34", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "03c47e07ba81ea728922ed3aea605f525064d6337c16e25998b3b4db8e54fc34", kill_on_drop: false }`
[INFO] [stdout] 03c47e07ba81ea728922ed3aea605f525064d6337c16e25998b3b4db8e54fc34
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-25/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-25/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ea5fc319b35b950afd9624dfbe9eb81f08be7eaf37851d45d4911dddf1a87671
[INFO] running `Command { std: "docker" "start" "-a" "ea5fc319b35b950afd9624dfbe9eb81f08be7eaf37851d45d4911dddf1a87671", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v0.1.7
[INFO] [stderr]     Checking rand_core v0.4.2
[INFO] [stderr]     Checking rand_core v0.3.1
[INFO] [stderr]     Checking rand_jitter v0.1.4
[INFO] [stderr]     Checking rand_os v0.1.3
[INFO] [stderr]     Checking rand_isaac v0.1.1
[INFO] [stderr]     Checking rand_hc v0.1.0
[INFO] [stderr]     Checking rand_xorshift v0.1.1
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]     Checking briliang_exercise v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> tests/structure/mod.rs:78:22
[INFO] [stdout]    |
[INFO] [stdout] 78 |         struct Car {};
[INFO] [stdout]    |                      ^ help: remove this semicolon
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(redundant_semicolons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> tests/functional_feature/mod.rs:225:13
[INFO] [stdout]     |
[INFO] [stdout] 225 |         let mut counter = Counter::new();
[INFO] [stdout]     |             ----^^^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> tests/collections/mod.rs:140:9
[INFO] [stdout]     |
[INFO] [stdout] 140 |         &hello[0..1];
[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] 140 |         let _ = &hello[0..1];
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.80s
[INFO] running `Command { std: "docker" "inspect" "ea5fc319b35b950afd9624dfbe9eb81f08be7eaf37851d45d4911dddf1a87671", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ea5fc319b35b950afd9624dfbe9eb81f08be7eaf37851d45d4911dddf1a87671", kill_on_drop: false }`
[INFO] [stdout] ea5fc319b35b950afd9624dfbe9eb81f08be7eaf37851d45d4911dddf1a87671