[INFO] cloning repository https://github.com/ezhang7423/arena
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ezhang7423/arena" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fezhang7423%2Farena", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fezhang7423%2Farena'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 5fbba54da28caea5181d082e62861309ba51d2ed
[INFO] checking ezhang7423/arena against master#297a8018b525c28ef10ee6a91d61954839b508b9 for pr-95565
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fezhang7423%2Farena" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ezhang7423/arena on toolchain 297a8018b525c28ef10ee6a91d61954839b508b9
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+297a8018b525c28ef10ee6a91d61954839b508b9" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ezhang7423/arena
[INFO] finished tweaking git repo https://github.com/ezhang7423/arena
[INFO] tweaked toml for git repo https://github.com/ezhang7423/arena written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/ezhang7423/arena already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+297a8018b525c28ef10ee6a91d61954839b508b9" "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-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:eaef2f80f755933c374d2ae5edccceec0c1312ceb8a4e0b6404e8ab76561e1e5" "/opt/rustwide/cargo-home/bin/cargo" "+297a8018b525c28ef10ee6a91d61954839b508b9" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 035725ac9e5f6fe29d8ce1e0a839d37ba71697e6b76bd8b9af462953ca0e7264
[INFO] running `Command { std: "docker" "start" "-a" "035725ac9e5f6fe29d8ce1e0a839d37ba71697e6b76bd8b9af462953ca0e7264", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "035725ac9e5f6fe29d8ce1e0a839d37ba71697e6b76bd8b9af462953ca0e7264", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "035725ac9e5f6fe29d8ce1e0a839d37ba71697e6b76bd8b9af462953ca0e7264", kill_on_drop: false }`
[INFO] [stdout] 035725ac9e5f6fe29d8ce1e0a839d37ba71697e6b76bd8b9af462953ca0e7264
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:eaef2f80f755933c374d2ae5edccceec0c1312ceb8a4e0b6404e8ab76561e1e5" "/opt/rustwide/cargo-home/bin/cargo" "+297a8018b525c28ef10ee6a91d61954839b508b9" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e9c6385bb33a07e6dd4b01f6e78ffff878112fbf0f74ebe7f46684fcc13d5803
[INFO] running `Command { std: "docker" "start" "-a" "e9c6385bb33a07e6dd4b01f6e78ffff878112fbf0f74ebe7f46684fcc13d5803", kill_on_drop: false }`
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking generational-arena v0.2.8
[INFO] [stderr]     Checking arena v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: type `child` should have an upper camel case name
[INFO] [stdout]   --> src/main.rs:56:8
[INFO] [stdout]    |
[INFO] [stdout] 56 | struct child {
[INFO] [stdout]    |        ^^^^^ help: convert the identifier to upper camel case (notice the capitalization): `Child`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_camel_case_types)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type `child` should have an upper camel case name
[INFO] [stdout]   --> src/main.rs:56:8
[INFO] [stdout]    |
[INFO] [stdout] 56 | struct child {
[INFO] [stdout]    |        ^^^^^ help: convert the identifier to upper camel case (notice the capitalization): `Child`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_camel_case_types)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `borrow::BorrowMut`
[INFO] [stdout]  --> src/main.rs:2:11
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::{borrow::BorrowMut, rc::Rc};
[INFO] [stdout]   |           ^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `borrow::BorrowMut`
[INFO] [stdout]  --> src/main.rs:2:11
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::{borrow::BorrowMut, rc::Rc};
[INFO] [stdout]   |           ^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `borrow`
[INFO] [stdout]   --> src/main.rs:18:8
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn borrow(&self) -> Ref<T> {
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `borrow`
[INFO] [stdout]   --> src/main.rs:18:8
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn borrow(&self) -> Ref<T> {
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `child`
[INFO] [stdout]   --> src/main.rs:56:8
[INFO] [stdout]    |
[INFO] [stdout] 56 | struct child {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `child`
[INFO] [stdout]   --> src/main.rs:56:8
[INFO] [stdout]    |
[INFO] [stdout] 56 | struct child {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.53s
[INFO] running `Command { std: "docker" "inspect" "e9c6385bb33a07e6dd4b01f6e78ffff878112fbf0f74ebe7f46684fcc13d5803", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e9c6385bb33a07e6dd4b01f6e78ffff878112fbf0f74ebe7f46684fcc13d5803", kill_on_drop: false }`
[INFO] [stdout] e9c6385bb33a07e6dd4b01f6e78ffff878112fbf0f74ebe7f46684fcc13d5803