[INFO] fetching crate briliang_exercise 0.1.0...
[INFO] checking briliang_exercise-0.1.0 against try#3d9fdbff4f377de96b3a51174e7a64086bee9a5c for pr-81477
[INFO] extracting crate briliang_exercise 0.1.0 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate briliang_exercise 0.1.0 on toolchain 3d9fdbff4f377de96b3a51174e7a64086bee9a5c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3d9fdbff4f377de96b3a51174e7a64086bee9a5c" "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-12/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3d9fdbff4f377de96b3a51174e7a64086bee9a5c" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3d9fdbff4f377de96b3a51174e7a64086bee9a5c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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" "+3d9fdbff4f377de96b3a51174e7a64086bee9a5c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 99146269d97714aa75082d063cb89d1d9fb1be389c654102eaba408d815e407e
[INFO] running `Command { std: "docker" "start" "-a" "99146269d97714aa75082d063cb89d1d9fb1be389c654102eaba408d815e407e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "99146269d97714aa75082d063cb89d1d9fb1be389c654102eaba408d815e407e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "99146269d97714aa75082d063cb89d1d9fb1be389c654102eaba408d815e407e", kill_on_drop: false }`
[INFO] [stdout] 99146269d97714aa75082d063cb89d1d9fb1be389c654102eaba408d815e407e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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" "+3d9fdbff4f377de96b3a51174e7a64086bee9a5c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2fc8819e2669a3a92dc9c2c09ae6b13156c80caeb1a303af5e349e62d8c97cdc
[INFO] running `Command { std: "docker" "start" "-a" "2fc8819e2669a3a92dc9c2c09ae6b13156c80caeb1a303af5e349e62d8c97cdc", kill_on_drop: false }`
[INFO] [stderr]     Checking rand_core v0.4.2
[INFO] [stderr]    Compiling autocfg v0.1.7
[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_xorshift v0.1.1
[INFO] [stderr]     Checking rand_hc v0.1.0
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[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 2.69s
[INFO] running `Command { std: "docker" "inspect" "2fc8819e2669a3a92dc9c2c09ae6b13156c80caeb1a303af5e349e62d8c97cdc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2fc8819e2669a3a92dc9c2c09ae6b13156c80caeb1a303af5e349e62d8c97cdc", kill_on_drop: false }`
[INFO] [stdout] 2fc8819e2669a3a92dc9c2c09ae6b13156c80caeb1a303af5e349e62d8c97cdc