[INFO] cloning repository https://github.com/khanhtc1202/undefined-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/khanhtc1202/undefined-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkhanhtc1202%2Fundefined-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkhanhtc1202%2Fundefined-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f32eab722599cd94d832f6a03d75f218efd34090
[INFO] checking khanhtc1202/undefined-rust against master#5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f for pr-87248
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkhanhtc1202%2Fundefined-rust" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/khanhtc1202/undefined-rust on toolchain 5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/khanhtc1202/undefined-rust
[INFO] finished tweaking git repo https://github.com/khanhtc1202/undefined-rust
[INFO] tweaked toml for git repo https://github.com/khanhtc1202/undefined-rust written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/khanhtc1202/undefined-rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 89583c140ce7f0ebe9979f829b385cde3ac6f9db0b67e84940e5803dcfbb634c
[INFO] running `Command { std: "docker" "start" "-a" "89583c140ce7f0ebe9979f829b385cde3ac6f9db0b67e84940e5803dcfbb634c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "89583c140ce7f0ebe9979f829b385cde3ac6f9db0b67e84940e5803dcfbb634c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "89583c140ce7f0ebe9979f829b385cde3ac6f9db0b67e84940e5803dcfbb634c", kill_on_drop: false }`
[INFO] [stdout] 89583c140ce7f0ebe9979f829b385cde3ac6f9db0b67e84940e5803dcfbb634c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8d3c92b0158d32a24ea9066bd0e0d8df19f5d7f1374b8afba7ffa79b1d96972d
[INFO] running `Command { std: "docker" "start" "-a" "8d3c92b0158d32a24ea9066bd0e0d8df19f5d7f1374b8afba7ffa79b1d96972d", kill_on_drop: false }`
[INFO] [stderr]     Checking sandbox v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused doc comment
[INFO] [stdout]   --> src/mutexs.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 | /         /// To access the data inside the mutex, we use the lock method to acquire the lock.
[INFO] [stdout] 15 | |         ///
[INFO] [stdout] 16 | |         /// The call to lock would fail if another thread holding the lock panicked. => need unwrap()
[INFO] [stdout] 17 | |         ///
[INFO] [stdout] ...  |
[INFO] [stdout] 21 | |         /// after this line, we going out of inner scope and ref `num` will be drop => return the lock to main thread
[INFO] [stdout] 22 | |         /// using inner scope, we don’t risk forgetting to release the lock and blocking the mutex from being used by other threads
[INFO] [stdout]    | |___________________________________________________________________________________________________________________________________^
[INFO] [stdout] 23 |           let mut num = m.lock().unwrap();
[INFO] [stdout]    |           -------------------------------- rustdoc does not generate documentation for statements
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_doc_comments)]` on by default
[INFO] [stdout]    = help: use `//` for a plain comment
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused doc comment
[INFO] [stdout]   --> src/mutexs.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 | /         /// To access the data inside the mutex, we use the lock method to acquire the lock.
[INFO] [stdout] 15 | |         ///
[INFO] [stdout] 16 | |         /// The call to lock would fail if another thread holding the lock panicked. => need unwrap()
[INFO] [stdout] 17 | |         ///
[INFO] [stdout] ...  |
[INFO] [stdout] 21 | |         /// after this line, we going out of inner scope and ref `num` will be drop => return the lock to main thread
[INFO] [stdout] 22 | |         /// using inner scope, we don’t risk forgetting to release the lock and blocking the mutex from being used by other threads
[INFO] [stdout]    | |___________________________________________________________________________________________________________________________________^
[INFO] [stdout] 23 |           let mut num = m.lock().unwrap();
[INFO] [stdout]    |           -------------------------------- rustdoc does not generate documentation for statements
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_doc_comments)]` on by default
[INFO] [stdout]    = help: use `//` for a plain comment
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.38s
[INFO] running `Command { std: "docker" "inspect" "8d3c92b0158d32a24ea9066bd0e0d8df19f5d7f1374b8afba7ffa79b1d96972d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8d3c92b0158d32a24ea9066bd0e0d8df19f5d7f1374b8afba7ffa79b1d96972d", kill_on_drop: false }`
[INFO] [stdout] 8d3c92b0158d32a24ea9066bd0e0d8df19f5d7f1374b8afba7ffa79b1d96972d