[INFO] cloning repository https://github.com/morka17/understanding_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/morka17/understanding_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmorka17%2Funderstanding_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmorka17%2Funderstanding_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] cd2b3d8daa9b89944929783690acee497b7b96f2
[INFO] checking morka17/understanding_rust against try#5e7498e6740d105521420ac0ab146e2c7a21596d for pr-138363
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmorka17%2Funderstanding_rust" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] [stderr] error: unable to write file .gitignore
[INFO] [stderr] fatal: unable to checkout working tree
[INFO] [stderr] warning: Clone succeeded, but checkout failed.
[INFO] [stderr] You can inspect what was checked out with 'git status'
[INFO] [stderr] and retry with 'git restore --source=HEAD :/'
[INFO] [stderr] 
[INFO] checking morka17/understanding_rust against try#5e7498e6740d105521420ac0ab146e2c7a21596d for pr-138363
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmorka17%2Funderstanding_rust" "/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/morka17/understanding_rust on toolchain 5e7498e6740d105521420ac0ab146e2c7a21596d
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+5e7498e6740d105521420ac0ab146e2c7a21596d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/morka17/understanding_rust
[INFO] finished tweaking git repo https://github.com/morka17/understanding_rust
[INFO] tweaked toml for git repo https://github.com/morka17/understanding_rust written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/morka17/understanding_rust 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" "+5e7498e6740d105521420ac0ab146e2c7a21596d" "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-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@sha256:1680c8fbd8dfb46fcd6d22e546df16ab0e007457dc29fcd9e987cdd5077fd1af" "/opt/rustwide/cargo-home/bin/cargo" "+5e7498e6740d105521420ac0ab146e2c7a21596d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f59d1196b90d0e649d5d664440f85da0dc29c1361b19ddc650c128999cf0a5c9
[INFO] running `Command { std: "docker" "start" "-a" "f59d1196b90d0e649d5d664440f85da0dc29c1361b19ddc650c128999cf0a5c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f59d1196b90d0e649d5d664440f85da0dc29c1361b19ddc650c128999cf0a5c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f59d1196b90d0e649d5d664440f85da0dc29c1361b19ddc650c128999cf0a5c9", kill_on_drop: false }`
[INFO] [stdout] f59d1196b90d0e649d5d664440f85da0dc29c1361b19ddc650c128999cf0a5c9
[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@sha256:1680c8fbd8dfb46fcd6d22e546df16ab0e007457dc29fcd9e987cdd5077fd1af" "/opt/rustwide/cargo-home/bin/cargo" "+5e7498e6740d105521420ac0ab146e2c7a21596d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1e060bea1468dcc96682963174af5bf0462dd27d1f0792c9d424689027ba9c68
[INFO] running `Command { std: "docker" "start" "-a" "1e060bea1468dcc96682963174af5bf0462dd27d1f0792c9d424689027ba9c68", kill_on_drop: false }`
[INFO] [stderr]     Checking understanding_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused imports: `RefCell` and `UnsafeCell`
[INFO] [stdout]   --> src/interior_mutability.rs:10:17
[INFO] [stdout]    |
[INFO] [stdout] 10 | use std::cell::{RefCell, UnsafeCell};
[INFO] [stdout]    |                 ^^^^^^^  ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::sync::Arc`
[INFO] [stdout]   --> src/interior_mutability.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 11 | use std::sync::Arc;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `RefCell`
[INFO] [stdout]   --> src/interior_mutability.rs:10:17
[INFO] [stdout]    |
[INFO] [stdout] 10 | use std::cell::{RefCell, UnsafeCell};
[INFO] [stdout]    |                 ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `AtomicUsize` and `Ordering`
[INFO] [stdout]   --> src/interior_mutability.rs:12:25
[INFO] [stdout]    |
[INFO] [stdout] 12 | use std::sync::atomic::{AtomicUsize, Ordering};
[INFO] [stdout]    |                         ^^^^^^^^^^^  ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `hint` and `thread`
[INFO] [stdout]   --> src/interior_mutability.rs:13:11
[INFO] [stdout]    |
[INFO] [stdout] 13 | use std::{hint, thread};
[INFO] [stdout]    |           ^^^^  ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `add` is never used
[INFO] [stdout]   --> src/pointer_type.rs:23:4
[INFO] [stdout]    |
[INFO] [stdout] 23 | fn add(x: i32, y: i32) -> i32 {
[INFO] [stdout]    |    ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `x` is never read
[INFO] [stdout]   --> src/pointer_type.rs:32:17
[INFO] [stdout]    |
[INFO] [stdout] 32 |         let mut x = add(5, 7);
[INFO] [stdout]    |                 ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `understanding_unsafeCell` should have a snake case name
[INFO] [stdout]   --> src/interior_mutability.rs:19:8
[INFO] [stdout]    |
[INFO] [stdout] 19 |     fn understanding_unsafeCell() {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^^^^^ help: convert the identifier to snake case: `understanding_unsafe_cell`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.08s
[INFO] running `Command { std: "docker" "inspect" "1e060bea1468dcc96682963174af5bf0462dd27d1f0792c9d424689027ba9c68", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1e060bea1468dcc96682963174af5bf0462dd27d1f0792c9d424689027ba9c68", kill_on_drop: false }`
[INFO] [stdout] 1e060bea1468dcc96682963174af5bf0462dd27d1f0792c9d424689027ba9c68