[INFO] fetching crate briliang_exercise 0.1.0...
[INFO] checking briliang_exercise-0.1.0 against master#90442458ac46b1d5eed752c316da25450f67285b for pr-81477
[INFO] extracting crate briliang_exercise 0.1.0 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate briliang_exercise 0.1.0 on toolchain 90442458ac46b1d5eed752c316da25450f67285b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "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-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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:ea7d7bff36b2ba8ce4de8bba1d2dea90376bc481f1a945a913994a8c492e40c1" "/opt/rustwide/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8c3ef6abe00723d5669fdbe58404c40012a80e3bf1a405dfcc8743144aa553b7
[INFO] running `Command { std: "docker" "start" "-a" "8c3ef6abe00723d5669fdbe58404c40012a80e3bf1a405dfcc8743144aa553b7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8c3ef6abe00723d5669fdbe58404c40012a80e3bf1a405dfcc8743144aa553b7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8c3ef6abe00723d5669fdbe58404c40012a80e3bf1a405dfcc8743144aa553b7", kill_on_drop: false }`
[INFO] [stdout] 8c3ef6abe00723d5669fdbe58404c40012a80e3bf1a405dfcc8743144aa553b7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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:ea7d7bff36b2ba8ce4de8bba1d2dea90376bc481f1a945a913994a8c492e40c1" "/opt/rustwide/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6e9c2f78152dce2fe193ac5328cf466d3bb052084353fda5bb3a5da99c5348fe
[INFO] running `Command { std: "docker" "start" "-a" "6e9c2f78152dce2fe193ac5328cf466d3bb052084353fda5bb3a5da99c5348fe", 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_xorshift v0.1.1
[INFO] [stderr]     Checking rand_isaac v0.1.1
[INFO] [stderr]     Checking rand_hc v0.1.0
[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]     |         ^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.73s
[INFO] running `Command { std: "docker" "inspect" "6e9c2f78152dce2fe193ac5328cf466d3bb052084353fda5bb3a5da99c5348fe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6e9c2f78152dce2fe193ac5328cf466d3bb052084353fda5bb3a5da99c5348fe", kill_on_drop: false }`
[INFO] [stdout] 6e9c2f78152dce2fe193ac5328cf466d3bb052084353fda5bb3a5da99c5348fe