[INFO] cloning repository https://github.com/cmhteixeira/little-book-of-semaphores-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/cmhteixeira/little-book-of-semaphores-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcmhteixeira%2Flittle-book-of-semaphores-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcmhteixeira%2Flittle-book-of-semaphores-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7d3264a246b4c10df64d48390cd49f8f4251b660
[INFO] checking cmhteixeira/little-book-of-semaphores-rust against 416264364aa47959f5827723e1d7dabc95d0744b for pr-162242
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcmhteixeira%2Flittle-book-of-semaphores-rust" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/cmhteixeira/little-book-of-semaphores-rust
[INFO] finished tweaking git repo https://github.com/cmhteixeira/little-book-of-semaphores-rust
[INFO] tweaked toml for git repo https://github.com/cmhteixeira/little-book-of-semaphores-rust written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/cmhteixeira/little-book-of-semaphores-rust on toolchain 416264364aa47959f5827723e1d7dabc95d0744b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+416264364aa47959f5827723e1d7dabc95d0744b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/cmhteixeira/little-book-of-semaphores-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" "+416264364aa47959f5827723e1d7dabc95d0744b" "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-2-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,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" "-m" "1610612736" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:8683fc1fc2eb5c9ac98e0d076ab094b2ffac7f99da555d2b6a2e27f346de2ec7" "sleep" "infinity", kill_on_drop: false }`
[INFO] [stdout] 2f9890eac12f7beed3dd68da83edf159ecf99a7788195c939a56e4fb5baf4a3f
[INFO] running `Command { std: "docker" "start" "2f9890eac12f7beed3dd68da83edf159ecf99a7788195c939a56e4fb5baf4a3f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2f9890eac12f7beed3dd68da83edf159ecf99a7788195c939a56e4fb5baf4a3f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-w" "/opt/rustwide/workdir" "--user" "0:0" "2f9890eac12f7beed3dd68da83edf159ecf99a7788195c939a56e4fb5baf4a3f" "/opt/rustwide/cargo-home/bin/cargo" "+416264364aa47959f5827723e1d7dabc95d0744b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2f9890eac12f7beed3dd68da83edf159ecf99a7788195c939a56e4fb5baf4a3f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-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" "-w" "/opt/rustwide/workdir" "--user" "0:0" "2f9890eac12f7beed3dd68da83edf159ecf99a7788195c939a56e4fb5baf4a3f" "/opt/rustwide/cargo-home/bin/cargo" "+416264364aa47959f5827723e1d7dabc95d0744b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr]     Checking little-book-semaphores-rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(optin_builtin_traits)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: removed in 1.50.0; see <https://github.com/rust-lang/rust/pull/79336> for more information
[INFO] [stdout]   = note: renamed to `auto_traits`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(optin_builtin_traits)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: removed in 1.50.0; see <https://github.com/rust-lang/rust/pull/79336> for more information
[INFO] [stdout]   = note: renamed to `auto_traits`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: negative impls are experimental
[INFO] [stdout]   --> src/dining_savages.rs:22:6
[INFO] [stdout]    |
[INFO] [stdout] 22 | impl !Sync for Cook {}
[INFO] [stdout]    |      ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #68318 <https://github.com/rust-lang/rust/issues/68318> for more information
[INFO] [stdout]    = help: add `#![feature(negative_impls)]` to the crate attributes to enable
[INFO] [stdout]    = note: this compiler was built on 2026-09-03; consider upgrading it if it is out of date
[INFO] [stdout]    = help: use marker types for now
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Duration`
[INFO] [stdout]  --> src/rendezvous.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::time::Duration;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: negative impls are experimental
[INFO] [stdout]   --> src/dining_savages.rs:22:6
[INFO] [stdout]    |
[INFO] [stdout] 22 | impl !Sync for Cook {}
[INFO] [stdout]    |      ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #68318 <https://github.com/rust-lang/rust/issues/68318> for more information
[INFO] [stdout]    = help: add `#![feature(negative_impls)]` to the crate attributes to enable
[INFO] [stdout]    = note: this compiler was built on 2026-09-03; consider upgrading it if it is out of date
[INFO] [stdout]    = help: use marker types for now
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Duration`
[INFO] [stdout]  --> src/rendezvous.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::time::Duration;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Mutex`
[INFO] [stdout]  --> src/mutex.rs:2:22
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::sync::{Arc, Mutex};
[INFO] [stdout]   |                      ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Mutex`
[INFO] [stdout]  --> src/mutex.rs:2:22
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::sync::{Arc, Mutex};
[INFO] [stdout]   |                      ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `DerefMut` and `Deref`
[INFO] [stdout]  --> src/mutex.rs:5:16
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::ops::{DerefMut, Deref};
[INFO] [stdout]   |                ^^^^^^^^  ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `RefCell`
[INFO] [stdout]  --> src/mutex.rs:6:17
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::cell::{RefCell, UnsafeCell};
[INFO] [stdout]   |                 ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Duration`
[INFO] [stdout]  --> src/barrier.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::time::Duration;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `AtomicBool`
[INFO] [stdout]  --> src/barrier.rs:4:25
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::sync::atomic::{AtomicBool, Ordering};
[INFO] [stdout]   |                         ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::alloc::System`
[INFO] [stdout]  --> src/barrier.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::alloc::System;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::borrow::Borrow`
[INFO] [stdout]  --> src/queue.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::sync::Mutex`
[INFO] [stdout]  --> src/queue.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::sync::Mutex;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::ops::DerefMut`
[INFO] [stdout]  --> src/queue.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::ops::DerefMut;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::rc::Rc`
[INFO] [stdout]  --> src/dining_savages.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::rc::Rc;
[INFO] [stdout]   |     ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `DerefMut` and `Deref`
[INFO] [stdout]  --> src/mutex.rs:5:16
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::ops::{DerefMut, Deref};
[INFO] [stdout]   |                ^^^^^^^^  ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `RefCell`
[INFO] [stdout]  --> src/mutex.rs:6:17
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::cell::{RefCell, UnsafeCell};
[INFO] [stdout]   |                 ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Duration`
[INFO] [stdout]  --> src/barrier.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::time::Duration;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `AtomicBool`
[INFO] [stdout]  --> src/barrier.rs:4:25
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::sync::atomic::{AtomicBool, Ordering};
[INFO] [stdout]   |                         ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::alloc::System`
[INFO] [stdout]  --> src/barrier.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::alloc::System;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::borrow::Borrow`
[INFO] [stdout]  --> src/queue.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated constant `std::u8::MAX`: replaced by the `MAX` associated constant on this type
[INFO] [stdout]   --> src/producer_consumer.rs:30:52
[INFO] [stdout]    |
[INFO] [stdout] 30 |             bounded_queue: Semaphore::new(std::u8::MAX),
[INFO] [stdout]    |                                                    ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::sync::Mutex`
[INFO] [stdout]  --> src/queue.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::sync::Mutex;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::ops::DerefMut`
[INFO] [stdout]  --> src/queue.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::ops::DerefMut;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::rc::Rc`
[INFO] [stdout]  --> src/dining_savages.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::rc::Rc;
[INFO] [stdout]   |     ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated constant `std::u8::MAX`: replaced by the `MAX` associated constant on this type
[INFO] [stdout]   --> src/producer_consumer.rs:30:52
[INFO] [stdout]    |
[INFO] [stdout] 30 |             bounded_queue: Semaphore::new(std::u8::MAX),
[INFO] [stdout]    |                                                    ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/mutex.rs:44:25
[INFO] [stdout]    |
[INFO] [stdout] 44 |                     let mut lock_obtained = arc.lock();
[INFO] [stdout]    |                         ----^^^^^^^^^^^^^
[INFO] [stdout]    |                         |
[INFO] [stdout]    |                         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0557, E0658.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0557`.
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/mutex.rs:44:25
[INFO] [stdout]    |
[INFO] [stdout] 44 |                     let mut lock_obtained = arc.lock();
[INFO] [stdout]    |                         ----^^^^^^^^^^^^^
[INFO] [stdout]    |                         |
[INFO] [stdout]    |                         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `little-book-semaphores-rust` (lib) due to 2 previous errors; 13 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] Some errors have detailed explanations: E0557, E0658.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0557`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `little-book-semaphores-rust` (lib test) due to 2 previous errors; 13 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "2f9890eac12f7beed3dd68da83edf159ecf99a7788195c939a56e4fb5baf4a3f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2f9890eac12f7beed3dd68da83edf159ecf99a7788195c939a56e4fb5baf4a3f", kill_on_drop: false }`
[INFO] [stdout] 2f9890eac12f7beed3dd68da83edf159ecf99a7788195c939a56e4fb5baf4a3f
