[INFO] cloning repository https://github.com/roberto3003/rust_collections
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/roberto3003/rust_collections" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Froberto3003%2Frust_collections", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Froberto3003%2Frust_collections'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] e2d3fa5142329953a07c69c2931a78826acbbf16
[INFO] checking roberto3003/rust_collections against 24e1a22664233bce1f9b5dc6eee7c1f74327e28c for pr-159343-retry
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Froberto3003%2Frust_collections" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/roberto3003/rust_collections
[INFO] finished tweaking git repo https://github.com/roberto3003/rust_collections
[INFO] tweaked toml for git repo https://github.com/roberto3003/rust_collections written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/roberto3003/rust_collections on toolchain 24e1a22664233bce1f9b5dc6eee7c1f74327e28c
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+24e1a22664233bce1f9b5dc6eee7c1f74327e28c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/roberto3003/rust_collections 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" "+24e1a22664233bce1f9b5dc6eee7c1f74327e28c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,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" "-m" "1610612736" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:3d5ced03c013a94a2f102a4510f48a6e9184255caf5fd8244f58017bde7f5210" "sleep" "infinity", kill_on_drop: false }`
[INFO] [stdout] d01e44c4013a5972848d221397c6e724b8210e39215df2c7a64020dc4ae7912b
[INFO] running `Command { std: "docker" "start" "d01e44c4013a5972848d221397c6e724b8210e39215df2c7a64020dc4ae7912b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d01e44c4013a5972848d221397c6e724b8210e39215df2c7a64020dc4ae7912b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-w" "/opt/rustwide/workdir" "--user" "0:0" "d01e44c4013a5972848d221397c6e724b8210e39215df2c7a64020dc4ae7912b" "/opt/rustwide/cargo-home/bin/cargo" "+24e1a22664233bce1f9b5dc6eee7c1f74327e28c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d01e44c4013a5972848d221397c6e724b8210e39215df2c7a64020dc4ae7912b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-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" "-w" "/opt/rustwide/workdir" "--user" "0:0" "d01e44c4013a5972848d221397c6e724b8210e39215df2c7a64020dc4ae7912b" "/opt/rustwide/cargo-home/bin/cargo" "+24e1a22664233bce1f9b5dc6eee7c1f74327e28c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr]     Checking collections v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `bio_students`
[INFO] [stdout]   --> src/main.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let bio_students = enrollment.get("biology");
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_bio_students`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `students`
[INFO] [stdout]   --> src/main.rs:36:9
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let students = enrollment.remove("biology");
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_students`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `bio_students`
[INFO] [stdout]   --> src/main.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let bio_students = enrollment.get("biology");
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_bio_students`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `students`
[INFO] [stdout]   --> src/main.rs:36:9
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let students = enrollment.remove("biology");
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_students`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.27s
[INFO] running `Command { std: "docker" "inspect" "d01e44c4013a5972848d221397c6e724b8210e39215df2c7a64020dc4ae7912b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d01e44c4013a5972848d221397c6e724b8210e39215df2c7a64020dc4ae7912b", kill_on_drop: false }`
[INFO] [stdout] d01e44c4013a5972848d221397c6e724b8210e39215df2c7a64020dc4ae7912b