[INFO] cloning repository https://github.com/t3m8ch/word-reverser
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/t3m8ch/word-reverser" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ft3m8ch%2Fword-reverser", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ft3m8ch%2Fword-reverser'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 40d61e38d759f435c8f06c460ed325d5bf1a37dd
[INFO] building t3m8ch/word-reverser against master#9bd71afb90c2a6e0348cdd4a2b10a3bf39908f19 for pr-117684
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ft3m8ch%2Fword-reverser" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/t3m8ch/word-reverser on toolchain 9bd71afb90c2a6e0348cdd4a2b10a3bf39908f19
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+9bd71afb90c2a6e0348cdd4a2b10a3bf39908f19" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/t3m8ch/word-reverser
[INFO] finished tweaking git repo https://github.com/t3m8ch/word-reverser
[INFO] tweaked toml for git repo https://github.com/t3m8ch/word-reverser written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/t3m8ch/word-reverser 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" "+9bd71afb90c2a6e0348cdd4a2b10a3bf39908f19" "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] building t3m8ch/word-reverser against try#53e03135c36e913ff664ce8329041b7e3c2fd358 for pr-117684
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ft3m8ch%2Fword-reverser" "/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/t3m8ch/word-reverser on toolchain 53e03135c36e913ff664ce8329041b7e3c2fd358
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+53e03135c36e913ff664ce8329041b7e3c2fd358" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/t3m8ch/word-reverser
[INFO] finished tweaking git repo https://github.com/t3m8ch/word-reverser
[INFO] tweaked toml for git repo https://github.com/t3m8ch/word-reverser written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/t3m8ch/word-reverser 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" "+53e03135c36e913ff664ce8329041b7e3c2fd358" "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-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@sha256:0c7e0e8312ad82a1bed3696438480b7da990d348377d3754e1cd95b06a8a36c7" "/opt/rustwide/cargo-home/bin/cargo" "+53e03135c36e913ff664ce8329041b7e3c2fd358" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2fc094c94b31bc7d7dcb5249128b25776f0f846a8e31904c08270da0909b03f4
[INFO] running `Command { std: "docker" "start" "-a" "2fc094c94b31bc7d7dcb5249128b25776f0f846a8e31904c08270da0909b03f4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2fc094c94b31bc7d7dcb5249128b25776f0f846a8e31904c08270da0909b03f4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2fc094c94b31bc7d7dcb5249128b25776f0f846a8e31904c08270da0909b03f4", kill_on_drop: false }`
[INFO] [stdout] 2fc094c94b31bc7d7dcb5249128b25776f0f846a8e31904c08270da0909b03f4
[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" "-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@sha256:0c7e0e8312ad82a1bed3696438480b7da990d348377d3754e1cd95b06a8a36c7" "/opt/rustwide/cargo-home/bin/cargo" "+53e03135c36e913ff664ce8329041b7e3c2fd358" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3e37bc4dfe365721a888395c866fb49639d9adc9398a2819e0dbc986caf10251
[INFO] running `Command { std: "docker" "start" "-a" "3e37bc4dfe365721a888395c866fb49639d9adc9398a2819e0dbc986caf10251", kill_on_drop: false }`
[INFO] [stderr]    Compiling word-reverser v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/lib.rs:64:13
[INFO] [stdout]    |
[INFO] [stdout] 64 | /             &chars[previous_i..i].iter()
[INFO] [stdout] 65 | |                 .for_each(|l| item.push(l.clone()));
[INFO] [stdout]    | |___________________________________________________^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 64 |             let _ = &chars[previous_i..i].iter()
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.71s
[INFO] running `Command { std: "docker" "inspect" "3e37bc4dfe365721a888395c866fb49639d9adc9398a2819e0dbc986caf10251", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3e37bc4dfe365721a888395c866fb49639d9adc9398a2819e0dbc986caf10251", kill_on_drop: false }`
[INFO] [stdout] 3e37bc4dfe365721a888395c866fb49639d9adc9398a2819e0dbc986caf10251
[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" "-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@sha256:0c7e0e8312ad82a1bed3696438480b7da990d348377d3754e1cd95b06a8a36c7" "/opt/rustwide/cargo-home/bin/cargo" "+53e03135c36e913ff664ce8329041b7e3c2fd358" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 55dd809f737ff151992757d12752902c6198070834f7041e3eda7825d3b1999b
[INFO] running `Command { std: "docker" "start" "-a" "55dd809f737ff151992757d12752902c6198070834f7041e3eda7825d3b1999b", kill_on_drop: false }`
[INFO] [stderr]    Compiling word-reverser v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/lib.rs:64:13
[INFO] [stdout]    |
[INFO] [stdout] 64 | /             &chars[previous_i..i].iter()
[INFO] [stdout] 65 | |                 .for_each(|l| item.push(l.clone()));
[INFO] [stdout]    | |___________________________________________________^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 64 |             let _ = &chars[previous_i..i].iter()
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/lib.rs:64:13
[INFO] [stdout]    |
[INFO] [stdout] 64 | /             &chars[previous_i..i].iter()
[INFO] [stdout] 65 | |                 .for_each(|l| item.push(l.clone()));
[INFO] [stdout]    | |___________________________________________________^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 64 |             let _ = &chars[previous_i..i].iter()
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.79s
[INFO] running `Command { std: "docker" "inspect" "55dd809f737ff151992757d12752902c6198070834f7041e3eda7825d3b1999b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "55dd809f737ff151992757d12752902c6198070834f7041e3eda7825d3b1999b", kill_on_drop: false }`
[INFO] [stdout] 55dd809f737ff151992757d12752902c6198070834f7041e3eda7825d3b1999b