[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#22572d0994593197593e2a1b7b18d720a9a349a7 for pr-126452-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fezhang7423%2Farena" "/workspace/builds/worker-1-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ezhang7423/arena on toolchain 22572d0994593197593e2a1b7b18d720a9a349a7
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+22572d0994593197593e2a1b7b18d720a9a349a7" "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-1-tc1/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: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+22572d0994593197593e2a1b7b18d720a9a349a7" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+22572d0994593197593e2a1b7b18d720a9a349a7" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1c5a593b21f070cbfc5fd1b023ce3df25ca5ed187b72c0904fdb7f5e52c6e005
[INFO] running `Command { std: "docker" "start" "-a" "1c5a593b21f070cbfc5fd1b023ce3df25ca5ed187b72c0904fdb7f5e52c6e005", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1c5a593b21f070cbfc5fd1b023ce3df25ca5ed187b72c0904fdb7f5e52c6e005", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1c5a593b21f070cbfc5fd1b023ce3df25ca5ed187b72c0904fdb7f5e52c6e005", kill_on_drop: false }`
[INFO] [stdout] 1c5a593b21f070cbfc5fd1b023ce3df25ca5ed187b72c0904fdb7f5e52c6e005
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+22572d0994593197593e2a1b7b18d720a9a349a7" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6c2dae0d89cdf25c9af30951efb957db1c17600e6fe8e56c16492768e5a22317
[INFO] running `Command { std: "docker" "start" "-a" "6c2dae0d89cdf25c9af30951efb957db1c17600e6fe8e56c16492768e5a22317", 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: method `borrow` is never used
[INFO] [stdout]   --> src/main.rs:18:8
[INFO] [stdout]    |
[INFO] [stdout] 12 | impl<T> Shared<T> {
[INFO] [stdout]    | ----------------- method in this implementation
[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: 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: struct `child` is never constructed
[INFO] [stdout]   --> src/main.rs:56:8
[INFO] [stdout]    |
[INFO] [stdout] 56 | struct child {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `borrow` is never used
[INFO] [stdout]   --> src/main.rs:18:8
[INFO] [stdout]    |
[INFO] [stdout] 12 | impl<T> Shared<T> {
[INFO] [stdout]    | ----------------- method in this implementation
[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 `child` is never constructed
[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` profile [unoptimized + debuginfo] target(s) in 0.18s
[INFO] running `Command { std: "docker" "inspect" "6c2dae0d89cdf25c9af30951efb957db1c17600e6fe8e56c16492768e5a22317", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6c2dae0d89cdf25c9af30951efb957db1c17600e6fe8e56c16492768e5a22317", kill_on_drop: false }`
[INFO] [stdout] 6c2dae0d89cdf25c9af30951efb957db1c17600e6fe8e56c16492768e5a22317