[INFO] cloning repository https://github.com/romangorisek/rust-book-chap-4
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/romangorisek/rust-book-chap-4" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fromangorisek%2Frust-book-chap-4", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fromangorisek%2Frust-book-chap-4'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b5aaebe6e33b990147033ac93ab9a10d533a6259
[INFO] checking romangorisek/rust-book-chap-4/b5aaebe6e33b990147033ac93ab9a10d533a6259 against master#5557f8c9d08d7f3f680943dcf97b6d4a7eb13aea for pr-124336
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fromangorisek%2Frust-book-chap-4" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/romangorisek/rust-book-chap-4 on toolchain 5557f8c9d08d7f3f680943dcf97b6d4a7eb13aea
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+5557f8c9d08d7f3f680943dcf97b6d4a7eb13aea" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/romangorisek/rust-book-chap-4
[INFO] finished tweaking git repo https://github.com/romangorisek/rust-book-chap-4
[INFO] tweaked toml for git repo https://github.com/romangorisek/rust-book-chap-4 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/romangorisek/rust-book-chap-4 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" "+5557f8c9d08d7f3f680943dcf97b6d4a7eb13aea" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[ERROR] this task or one of its parent failed!
[ERROR] no output for 300 seconds
[ERROR] note: run with `RUST_BACKTRACE=1` to display a backtrace.
[INFO] checking romangorisek/rust-book-chap-4/b5aaebe6e33b990147033ac93ab9a10d533a6259 against try#311f8b6ca41358db8ae08490a9ca0916f11e9de3 for pr-124336
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fromangorisek%2Frust-book-chap-4" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/romangorisek/rust-book-chap-4 on toolchain 311f8b6ca41358db8ae08490a9ca0916f11e9de3
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+311f8b6ca41358db8ae08490a9ca0916f11e9de3" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/romangorisek/rust-book-chap-4
[INFO] finished tweaking git repo https://github.com/romangorisek/rust-book-chap-4
[INFO] tweaked toml for git repo https://github.com/romangorisek/rust-book-chap-4 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/romangorisek/rust-book-chap-4 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" "+311f8b6ca41358db8ae08490a9ca0916f11e9de3" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[INFO] checking romangorisek/rust-book-chap-4/b5aaebe6e33b990147033ac93ab9a10d533a6259 against try#311f8b6ca41358db8ae08490a9ca0916f11e9de3 for pr-124336
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fromangorisek%2Frust-book-chap-4" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/romangorisek/rust-book-chap-4 on toolchain 311f8b6ca41358db8ae08490a9ca0916f11e9de3
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+311f8b6ca41358db8ae08490a9ca0916f11e9de3" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/romangorisek/rust-book-chap-4
[INFO] finished tweaking git repo https://github.com/romangorisek/rust-book-chap-4
[INFO] tweaked toml for git repo https://github.com/romangorisek/rust-book-chap-4 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/romangorisek/rust-book-chap-4 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" "+311f8b6ca41358db8ae08490a9ca0916f11e9de3" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[INFO] checking romangorisek/rust-book-chap-4/b5aaebe6e33b990147033ac93ab9a10d533a6259 against try#311f8b6ca41358db8ae08490a9ca0916f11e9de3 for pr-124336
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fromangorisek%2Frust-book-chap-4" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/romangorisek/rust-book-chap-4 on toolchain 311f8b6ca41358db8ae08490a9ca0916f11e9de3
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+311f8b6ca41358db8ae08490a9ca0916f11e9de3" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/romangorisek/rust-book-chap-4
[INFO] finished tweaking git repo https://github.com/romangorisek/rust-book-chap-4
[INFO] tweaked toml for git repo https://github.com/romangorisek/rust-book-chap-4 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/romangorisek/rust-book-chap-4 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" "+311f8b6ca41358db8ae08490a9ca0916f11e9de3" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:99613afd962a8cfa530ec1899472a458bd015a1ab0af876cf7eb06f6006d81ea" "/opt/rustwide/cargo-home/bin/cargo" "+311f8b6ca41358db8ae08490a9ca0916f11e9de3" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4a5ed482f71cd8461a4d7aba8fe9d0f119a4ca5c46ab633e6123b532585259de
[INFO] running `Command { std: "docker" "start" "-a" "4a5ed482f71cd8461a4d7aba8fe9d0f119a4ca5c46ab633e6123b532585259de", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4a5ed482f71cd8461a4d7aba8fe9d0f119a4ca5c46ab633e6123b532585259de", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4a5ed482f71cd8461a4d7aba8fe9d0f119a4ca5c46ab633e6123b532585259de", kill_on_drop: false }`
[INFO] [stdout] 4a5ed482f71cd8461a4d7aba8fe9d0f119a4ca5c46ab633e6123b532585259de
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "-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@sha256:99613afd962a8cfa530ec1899472a458bd015a1ab0af876cf7eb06f6006d81ea" "/opt/rustwide/cargo-home/bin/cargo" "+311f8b6ca41358db8ae08490a9ca0916f11e9de3" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b4dcbb4cc61ebbc1ed4e63cb9130d15e5de0ac6c82d7be255201326cb5d09a80
[INFO] running `Command { std: "docker" "start" "-a" "b4dcbb4cc61ebbc1ed4e63cb9130d15e5de0ac6c82d7be255201326cb5d09a80", kill_on_drop: false }`
[INFO] [stderr]     Checking ownership v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]  --> src/main.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let y = x;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]  --> src/main.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let y = x;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/main.rs:55:9
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let hello = &s[..5];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `world`
[INFO] [stdout]   --> src/main.rs:56:9
[INFO] [stdout]    |
[INFO] [stdout] 56 |     let world = &s[6..];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_world`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/main.rs:55:9
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let hello = &s[..5];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `world`
[INFO] [stdout]   --> src/main.rs:56:9
[INFO] [stdout]    |
[INFO] [stdout] 56 |     let world = &s[6..];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_world`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.09s
[INFO] running `Command { std: "docker" "inspect" "b4dcbb4cc61ebbc1ed4e63cb9130d15e5de0ac6c82d7be255201326cb5d09a80", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b4dcbb4cc61ebbc1ed4e63cb9130d15e5de0ac6c82d7be255201326cb5d09a80", kill_on_drop: false }`
[INFO] [stdout] b4dcbb4cc61ebbc1ed4e63cb9130d15e5de0ac6c82d7be255201326cb5d09a80