[INFO] fetching crate mpmc-ringbuf 0.1.4...
[INFO] checking mpmc-ringbuf-0.1.4 against master#c2f2db79ca3024f68d22b45aa22b570775c2c4ad for pr-124157
[INFO] extracting crate mpmc-ringbuf 0.1.4 into /workspace/builds/worker-2-tc1/source
[INFO] validating manifest of crates.io crate mpmc-ringbuf 0.1.4 on toolchain c2f2db79ca3024f68d22b45aa22b570775c2c4ad
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c2f2db79ca3024f68d22b45aa22b570775c2c4ad" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mpmc-ringbuf 0.1.4
[INFO] finished tweaking crates.io crate mpmc-ringbuf 0.1.4
[INFO] tweaked toml for crates.io crate mpmc-ringbuf 0.1.4 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c2f2db79ca3024f68d22b45aa22b570775c2c4ad" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 12 packages to latest compatible versions
[INFO] [stderr]       Adding rand v0.3.23 (latest: v0.8.5)
[INFO] [stderr]       Adding rand v0.4.6 (latest: v0.8.5)
[INFO] [stderr]       Adding rand_core v0.3.1 (latest: v0.6.4)
[INFO] [stderr]       Adding rand_core v0.4.2 (latest: v0.6.4)
[INFO] [stderr]       Adding rdrand v0.4.0 (latest: v0.8.3)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c2f2db79ca3024f68d22b45aa22b570775c2c4ad" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr] `license` should be used if the package license can be expressed with a standard SPDX expression.
[INFO] [stderr] `license-file` should be used if the package uses a non-standard license.
[INFO] [stderr] See https://doc.rust-lang.org/cargo/reference/manifest.html#the-license-and-license-file-fields for more information.
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded libmath v0.2.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:99613afd962a8cfa530ec1899472a458bd015a1ab0af876cf7eb06f6006d81ea" "/opt/rustwide/cargo-home/bin/cargo" "+c2f2db79ca3024f68d22b45aa22b570775c2c4ad" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7428c2944dc83825d0997bb2ade86608a4c85c9f7bf77ac57365cadc4c8c5590
[INFO] running `Command { std: "docker" "start" "-a" "7428c2944dc83825d0997bb2ade86608a4c85c9f7bf77ac57365cadc4c8c5590", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7428c2944dc83825d0997bb2ade86608a4c85c9f7bf77ac57365cadc4c8c5590", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7428c2944dc83825d0997bb2ade86608a4c85c9f7bf77ac57365cadc4c8c5590", kill_on_drop: false }`
[INFO] [stdout] 7428c2944dc83825d0997bb2ade86608a4c85c9f7bf77ac57365cadc4c8c5590
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:99613afd962a8cfa530ec1899472a458bd015a1ab0af876cf7eb06f6006d81ea" "/opt/rustwide/cargo-home/bin/cargo" "+c2f2db79ca3024f68d22b45aa22b570775c2c4ad" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ee835da6edf306b6529785cc82b5bada3a443130416bea9b105669be0a66e450
[INFO] running `Command { std: "docker" "start" "-a" "ee835da6edf306b6529785cc82b5bada3a443130416bea9b105669be0a66e450", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr] `license` should be used if the package license can be expressed with a standard SPDX expression.
[INFO] [stderr] `license-file` should be used if the package uses a non-standard license.
[INFO] [stderr] See https://doc.rust-lang.org/cargo/reference/manifest.html#the-license-and-license-file-fields for more information.
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking rand v0.3.23
[INFO] [stderr]     Checking libmath v0.2.1
[INFO] [stderr]     Checking mpmc-ringbuf v0.1.4 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `core::panicking::panic`
[INFO] [stdout]  --> src/core.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 | use core::panicking::panic;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::os::unix::raw::mode_t`
[INFO] [stdout]   --> src/core.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 | use std::os::unix::raw::mode_t;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `core::panicking::panic`
[INFO] [stdout]  --> src/core.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 | use core::panicking::panic;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::os::unix::raw::mode_t`
[INFO] [stdout]   --> src/core.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 | use std::os::unix::raw::mode_t;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: use of unstable library feature 'panic_internals': internal details of the implementation of the `panic!` and related macros
[INFO] [stdout]  --> src/core.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 | use core::panicking::panic;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: add `#![feature(panic_internals)]` to the crate attributes to enable
[INFO] [stdout]   = note: this compiler was built on 2024-04-23; consider upgrading it if it is out of date
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated type alias `std::os::unix::raw::mode_t`: these type aliases are no longer supported by the standard library, the `libc` crate on crates.io should be used instead for the correct definitions
[INFO] [stdout]   --> src/core.rs:12:25
[INFO] [stdout]    |
[INFO] [stdout] 12 | use std::os::unix::raw::mode_t;
[INFO] [stdout]    |                         ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: use of unstable library feature 'panic_internals': internal details of the implementation of the `panic!` and related macros
[INFO] [stdout]  --> src/core.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 | use core::panicking::panic;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: add `#![feature(panic_internals)]` to the crate attributes to enable
[INFO] [stdout]   = note: this compiler was built on 2024-04-23; consider upgrading it if it is out of date
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `core_panic`
[INFO] [stdout]   --> src/lib.rs:27:12
[INFO] [stdout]    |
[INFO] [stdout] 27 | #![feature(core_panic)]
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated type alias `std::os::unix::raw::mode_t`: these type aliases are no longer supported by the standard library, the `libc` crate on crates.io should be used instead for the correct definitions
[INFO] [stdout]   --> src/core.rs:12:25
[INFO] [stdout]    |
[INFO] [stdout] 12 | use std::os::unix::raw::mode_t;
[INFO] [stdout]    |                         ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `core_panic`
[INFO] [stdout]   --> src/lib.rs:27:12
[INFO] [stdout]    |
[INFO] [stdout] 27 | #![feature(core_panic)]
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]   --> src/core.rs:53:13
[INFO] [stdout]    |
[INFO] [stdout] 52 |             panic!("Rb is running, please config before running");
[INFO] [stdout]    |             ----------------------------------------------------- any code following this expression is unreachable
[INFO] [stdout] 53 |             return;
[INFO] [stdout]    |             ^^^^^^^ unreachable statement
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]   --> src/core.rs:61:13
[INFO] [stdout]    |
[INFO] [stdout] 60 |             panic!("Rb is running, please config before running");
[INFO] [stdout]    |             ----------------------------------------------------- any code following this expression is unreachable
[INFO] [stdout] 61 |             return;
[INFO] [stdout]    |             ^^^^^^^ unreachable statement
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]   --> src/core.rs:53:13
[INFO] [stdout]    |
[INFO] [stdout] 52 |             panic!("Rb is running, please config before running");
[INFO] [stdout]    |             ----------------------------------------------------- any code following this expression is unreachable
[INFO] [stdout] 53 |             return;
[INFO] [stdout]    |             ^^^^^^^ unreachable statement
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]   --> src/core.rs:61:13
[INFO] [stdout]    |
[INFO] [stdout] 60 |             panic!("Rb is running, please config before running");
[INFO] [stdout]    |             ----------------------------------------------------- any code following this expression is unreachable
[INFO] [stdout] 61 |             return;
[INFO] [stdout]    |             ^^^^^^^ unreachable statement
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::borrow::BorrowMut`
[INFO] [stdout]  --> src/core.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::borrow::BorrowMut;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:395:17
[INFO] [stdout]     |
[INFO] [stdout] 395 |             let mut w_page_index = self.w_page_index;
[INFO] [stdout]     |                 ----^^^^^^^^^^^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `read_index_end` is never read
[INFO] [stdout]    --> src/core.rs:447:21
[INFO] [stdout]     |
[INFO] [stdout] 447 |             let mut read_index_end = self.r_index;
[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] error: aborting due to 2 previous errors; 8 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0635, E0658.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0635`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `mpmc-ringbuf` (lib) due to 3 previous errors; 8 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unused import: `std::borrow::BorrowMut`
[INFO] [stdout]  --> src/core.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::borrow::BorrowMut;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:395:17
[INFO] [stdout]     |
[INFO] [stdout] 395 |             let mut w_page_index = self.w_page_index;
[INFO] [stdout]     |                 ----^^^^^^^^^^^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `read_index_end` is never read
[INFO] [stdout]    --> src/core.rs:447:21
[INFO] [stdout]     |
[INFO] [stdout] 447 |             let mut read_index_end = self.r_index;
[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: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:663:13
[INFO] [stdout]     |
[INFO] [stdout] 663 |         let mut writer1 = msg_queue.add_producer();
[INFO] [stdout]     |             ----^^^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `c1_id` is never read
[INFO] [stdout]    --> src/core.rs:685:17
[INFO] [stdout]     |
[INFO] [stdout] 685 |         let mut c1_id = 0;
[INFO] [stdout]     |                 ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `c2_id` is never read
[INFO] [stdout]    --> src/core.rs:686:17
[INFO] [stdout]     |
[INFO] [stdout] 686 |         let mut c2_id = 0;
[INFO] [stdout]     |                 ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]    --> src/core.rs:699:17
[INFO] [stdout]     |
[INFO] [stdout] 699 |             for i in 0..100 {
[INFO] [stdout]     |                 ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]    --> src/core.rs:708:17
[INFO] [stdout]     |
[INFO] [stdout] 708 |             for i in 0..100 {
[INFO] [stdout]     |                 ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:682:13
[INFO] [stdout]     |
[INFO] [stdout] 682 |         let mut msg_queue: Arc<Mutex<MsgQueue<u8>>> = Arc::new(Mutex::new(MsgQueue::new()));
[INFO] [stdout]     |             ----^^^^^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:689:17
[INFO] [stdout]     |
[INFO] [stdout] 689 |             let mut c1 = msg_lock.add_consumer();
[INFO] [stdout]     |                 ----^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:690:17
[INFO] [stdout]     |
[INFO] [stdout] 690 |             let mut c2 = msg_lock.add_consumer();
[INFO] [stdout]     |                 ----^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:727:13
[INFO] [stdout]     |
[INFO] [stdout] 727 |         let mut msg_queue = Rc::new(RefCell::new(MsgQueue::<String>::new()));
[INFO] [stdout]     |             ----^^^^^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:729:13
[INFO] [stdout]     |
[INFO] [stdout] 729 |         let mut p1 = msg_queue.borrow_mut().add_producer();
[INFO] [stdout]     |             ----^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c1`
[INFO] [stdout]    --> src/core.rs:747:17
[INFO] [stdout]     |
[INFO] [stdout] 747 |         let mut c1 = msg_queue.borrow_mut().add_consumer();
[INFO] [stdout]     |                 ^^ help: if this is intentional, prefix it with an underscore: `_c1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:744:13
[INFO] [stdout]     |
[INFO] [stdout] 744 |         let mut msg_queue = Rc::new(RefCell::new(MsgQueue::<String>::new()));
[INFO] [stdout]     |             ----^^^^^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:747:13
[INFO] [stdout]     |
[INFO] [stdout] 747 |         let mut c1 = msg_queue.borrow_mut().add_consumer();
[INFO] [stdout]     |             ----^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:748:13
[INFO] [stdout]     |
[INFO] [stdout] 748 |         let mut p1 = msg_queue.borrow_mut().add_producer();
[INFO] [stdout]     |             ----^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c1`
[INFO] [stdout]    --> src/core.rs:758:17
[INFO] [stdout]     |
[INFO] [stdout] 758 |         let mut c1 = msg_queue.borrow_mut().add_consumer();
[INFO] [stdout]     |                 ^^ help: if this is intentional, prefix it with an underscore: `_c1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `p1`
[INFO] [stdout]    --> src/core.rs:759:17
[INFO] [stdout]     |
[INFO] [stdout] 759 |         let mut p1 = msg_queue.borrow_mut().add_producer();
[INFO] [stdout]     |                 ^^ help: if this is intentional, prefix it with an underscore: `_p1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:756:13
[INFO] [stdout]     |
[INFO] [stdout] 756 |         let mut msg_queue = Rc::new(RefCell::new(MsgQueue::<String>::new()));
[INFO] [stdout]     |             ----^^^^^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:758:13
[INFO] [stdout]     |
[INFO] [stdout] 758 |         let mut c1 = msg_queue.borrow_mut().add_consumer();
[INFO] [stdout]     |             ----^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:759:13
[INFO] [stdout]     |
[INFO] [stdout] 759 |         let mut p1 = msg_queue.borrow_mut().add_producer();
[INFO] [stdout]     |             ----^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors; 27 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0635, E0658.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0635`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `mpmc-ringbuf` (lib test) due to 3 previous errors; 27 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "ee835da6edf306b6529785cc82b5bada3a443130416bea9b105669be0a66e450", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ee835da6edf306b6529785cc82b5bada3a443130416bea9b105669be0a66e450", kill_on_drop: false }`
[INFO] [stdout] ee835da6edf306b6529785cc82b5bada3a443130416bea9b105669be0a66e450
