[INFO] updating cached repository https://github.com/JasonShin/rustlings-solution
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 831292b998ec38377309f2c270cd99d2168f01f8
[INFO] checking JasonShin/rustlings-solution/831292b998ec38377309f2c270cd99d2168f01f8 against try#7014e13d5becc920d4bea3cd87942c8a13d359bf+rustflags=-Dtail_expr_drop_order for pr-129864
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJasonShin%2Frustlings-solution" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/JasonShin/rustlings-solution on toolchain 7014e13d5becc920d4bea3cd87942c8a13d359bf
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+7014e13d5becc920d4bea3cd87942c8a13d359bf" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/JasonShin/rustlings-solution
[INFO] finished tweaking git repo https://github.com/JasonShin/rustlings-solution
[INFO] tweaked toml for git repo https://github.com/JasonShin/rustlings-solution written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/JasonShin/rustlings-solution 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" "+7014e13d5becc920d4bea3cd87942c8a13d359bf" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/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:ceb6ea022f8a89cebbe621bb4987e73a935bd40dfbb726f832cfff4742a5b95a" "/opt/rustwide/cargo-home/bin/cargo" "+7014e13d5becc920d4bea3cd87942c8a13d359bf" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d7e973e580aa9270c858332d2befaaa1ff894b6173536fcf48db0ff9e95c6439
[INFO] running `Command { std: "docker" "start" "-a" "d7e973e580aa9270c858332d2befaaa1ff894b6173536fcf48db0ff9e95c6439", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d7e973e580aa9270c858332d2befaaa1ff894b6173536fcf48db0ff9e95c6439", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d7e973e580aa9270c858332d2befaaa1ff894b6173536fcf48db0ff9e95c6439", kill_on_drop: false }`
[INFO] [stdout] d7e973e580aa9270c858332d2befaaa1ff894b6173536fcf48db0ff9e95c6439
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/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 -Dtail_expr_drop_order" "-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:ceb6ea022f8a89cebbe621bb4987e73a935bd40dfbb726f832cfff4742a5b95a" "/opt/rustwide/cargo-home/bin/cargo" "+7014e13d5becc920d4bea3cd87942c8a13d359bf" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 44e9fd8f5407a1ea72b4dcbeb93befe6f6adc2f6b4c760db85927e2293adba93
[INFO] running `Command { std: "docker" "start" "-a" "44e9fd8f5407a1ea72b4dcbeb93befe6f6adc2f6b4c760db85927e2293adba93", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.93
[INFO] [stderr]    Compiling proc-macro2 v1.0.26
[INFO] [stderr]    Compiling syn v1.0.70
[INFO] [stderr]    Compiling serde_derive v1.0.125
[INFO] [stderr]    Compiling serde v1.0.125
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]     Checking lock_api v0.4.3
[INFO] [stderr]    Compiling serde_json v1.0.64
[INFO] [stderr]     Checking slab v0.4.3
[INFO] [stderr]    Compiling unicode-segmentation v1.7.1
[INFO] [stderr]    Compiling argh_shared v0.1.4
[INFO] [stderr]     Checking regex v1.4.6
[INFO] [stderr]     Checking predicates-tree v1.0.2
[INFO] [stderr]    Compiling heck v0.3.2
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking parking_lot_core v0.8.3
[INFO] [stderr]     Checking net2 v0.2.37
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking terminal_size v0.1.16
[INFO] [stderr]     Checking inotify-sys v0.1.5
[INFO] [stderr]     Checking filetime v0.2.14
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking clicolors-control v1.0.1
[INFO] [stderr]     Checking termios v0.3.3
[INFO] [stderr]     Checking number_prefix v0.2.8
[INFO] [stderr]     Checking float-cmp v0.8.0
[INFO] [stderr]     Checking inotify v0.7.1
[INFO] [stderr]     Checking console v0.14.1
[INFO] [stderr]     Checking parking_lot v0.11.1
[INFO] [stderr]     Checking predicates v1.0.7
[INFO] [stderr]     Checking mio v0.6.23
[INFO] [stderr]     Checking console v0.7.7
[INFO] [stderr]     Checking indicatif v0.10.3
[INFO] [stderr]     Checking mio-extras v2.0.6
[INFO] [stderr]     Checking notify v4.0.16
[INFO] [stderr]    Compiling argh_derive v0.1.4
[INFO] [stderr]     Checking argh v0.1.4
[INFO] [stderr]     Checking toml v0.4.10
[INFO] [stderr]     Checking rustlings v4.4.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking escargot v0.4.0
[INFO] [stderr]     Checking assert_cmd v0.11.1
[INFO] [stdout] warning: unused import: `std::error`
[INFO] [stdout]  --> examples/hmm.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::error;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::fmt`
[INFO] [stdout]  --> examples/hmm.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::fmt;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `name` and `age` are never read
[INFO] [stdout]   --> examples/hmm.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 10 | struct Person {
[INFO] [stdout]    |        ------ fields in this struct
[INFO] [stdout] 11 |     name: String,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 12 |     age: usize,
[INFO] [stdout]    |     ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Person` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 11.25s
[INFO] running `Command { std: "docker" "inspect" "44e9fd8f5407a1ea72b4dcbeb93befe6f6adc2f6b4c760db85927e2293adba93", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "44e9fd8f5407a1ea72b4dcbeb93befe6f6adc2f6b4c760db85927e2293adba93", kill_on_drop: false }`
[INFO] [stdout] 44e9fd8f5407a1ea72b4dcbeb93befe6f6adc2f6b4c760db85927e2293adba93