[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 try#4e3d7541a523df82cea75064e44e60ae9a008bcb for pr-97427
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fezhang7423%2Farena" "/workspace/builds/worker-9/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ezhang7423/arena on toolchain 4e3d7541a523df82cea75064e44e60ae9a008bcb
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4e3d7541a523df82cea75064e44e60ae9a008bcb" "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-9/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" "+4e3d7541a523df82cea75064e44e60ae9a008bcb" "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-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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:ac0d0aa6ec8ed129e241004a6179c99fa0d2616f50ba759c5b60bd26d0fafa02" "/opt/rustwide/cargo-home/bin/cargo" "+4e3d7541a523df82cea75064e44e60ae9a008bcb" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c06c3886ec1b319616cc6bbd6ab1447be45d9d42beb031cd99836d0872d84249
[INFO] running `Command { std: "docker" "start" "-a" "c06c3886ec1b319616cc6bbd6ab1447be45d9d42beb031cd99836d0872d84249", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c06c3886ec1b319616cc6bbd6ab1447be45d9d42beb031cd99836d0872d84249", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c06c3886ec1b319616cc6bbd6ab1447be45d9d42beb031cd99836d0872d84249", kill_on_drop: false }`
[INFO] [stdout] c06c3886ec1b319616cc6bbd6ab1447be45d9d42beb031cd99836d0872d84249
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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:ac0d0aa6ec8ed129e241004a6179c99fa0d2616f50ba759c5b60bd26d0fafa02" "/opt/rustwide/cargo-home/bin/cargo" "+4e3d7541a523df82cea75064e44e60ae9a008bcb" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 284dc76be680d42bc584e3076df06f9751f68433e3f139d71766adea18db5eaa
[INFO] running `Command { std: "docker" "start" "-a" "284dc76be680d42bc584e3076df06f9751f68433e3f139d71766adea18db5eaa", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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: 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: 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: 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 4.81s
[INFO] running `Command { std: "docker" "inspect" "284dc76be680d42bc584e3076df06f9751f68433e3f139d71766adea18db5eaa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "284dc76be680d42bc584e3076df06f9751f68433e3f139d71766adea18db5eaa", kill_on_drop: false }`
[INFO] [stdout] 284dc76be680d42bc584e3076df06f9751f68433e3f139d71766adea18db5eaa