[INFO] fetching crate immutable 0.1.1...
[INFO] checking immutable-0.1.1 against try#82acd1d76add2232e19c1f0feb250d2a19ec6efe for pr-81213
[INFO] extracting crate immutable 0.1.1 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate immutable 0.1.1 on toolchain 82acd1d76add2232e19c1f0feb250d2a19ec6efe
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+82acd1d76add2232e19c1f0feb250d2a19ec6efe" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate immutable 0.1.1
[INFO] finished tweaking crates.io crate immutable 0.1.1
[INFO] tweaked toml for crates.io crate immutable 0.1.1 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+82acd1d76add2232e19c1f0feb250d2a19ec6efe" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+82acd1d76add2232e19c1f0feb250d2a19ec6efe" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "rustops/crates-build-env@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+82acd1d76add2232e19c1f0feb250d2a19ec6efe" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 1ebc0f1a2e3ec1fd7a3ae66545aad112fe6aa32ae4145fc8cc77a75580eb81fb
[INFO] running `Command { std: "docker" "start" "-a" "1ebc0f1a2e3ec1fd7a3ae66545aad112fe6aa32ae4145fc8cc77a75580eb81fb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1ebc0f1a2e3ec1fd7a3ae66545aad112fe6aa32ae4145fc8cc77a75580eb81fb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1ebc0f1a2e3ec1fd7a3ae66545aad112fe6aa32ae4145fc8cc77a75580eb81fb", kill_on_drop: false }`
[INFO] [stdout] 1ebc0f1a2e3ec1fd7a3ae66545aad112fe6aa32ae4145fc8cc77a75580eb81fb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "rustops/crates-build-env@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+82acd1d76add2232e19c1f0feb250d2a19ec6efe" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 738d586008e8459b973635d0604e97c92b74d2c1ecfa0ea24eb3ef4cf43e1aa8
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "738d586008e8459b973635d0604e97c92b74d2c1ecfa0ea24eb3ef4cf43e1aa8", kill_on_drop: false }`
[INFO] [stderr]     Checking immutable v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::vec::IntoIter`
[INFO] [stdout]  --> src/list.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::vec::IntoIter;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::vec::IntoIter`
[INFO] [stdout]  --> src/list.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::vec::IntoIter;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused attribute
[INFO] [stdout]  --> src/list.rs:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | #[macro_escape]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_attributes)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused attribute
[INFO] [stdout]   --> src/tree/binary_tree.rs:11:1
[INFO] [stdout]    |
[INFO] [stdout] 11 | #[macro_escape]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused attribute
[INFO] [stdout]  --> src/list.rs:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | #[macro_escape]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_attributes)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused attribute
[INFO] [stdout]   --> src/tree/binary_tree.rs:11:1
[INFO] [stdout]    |
[INFO] [stdout] 11 | #[macro_escape]
[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 0.49s
[INFO] running `Command { std: "docker" "inspect" "738d586008e8459b973635d0604e97c92b74d2c1ecfa0ea24eb3ef4cf43e1aa8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "738d586008e8459b973635d0604e97c92b74d2c1ecfa0ea24eb3ef4cf43e1aa8", kill_on_drop: false }`
[INFO] [stdout] 738d586008e8459b973635d0604e97c92b74d2c1ecfa0ea24eb3ef4cf43e1aa8