[INFO] fetching crate ferris-gc 0.1.5...
[INFO] checking ferris-gc-0.1.5 against try#a7a572ce3edd6d476191fbfe92c9c1986e009b34 for pr-87190-3
[INFO] extracting crate ferris-gc 0.1.5 into /workspace/builds/worker-86/source
[INFO] validating manifest of crates.io crate ferris-gc 0.1.5 on toolchain a7a572ce3edd6d476191fbfe92c9c1986e009b34
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a7a572ce3edd6d476191fbfe92c9c1986e009b34" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate ferris-gc 0.1.5
[INFO] finished tweaking crates.io crate ferris-gc 0.1.5
[INFO] tweaked toml for crates.io crate ferris-gc 0.1.5 written to /workspace/builds/worker-86/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a7a572ce3edd6d476191fbfe92c9c1986e009b34" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a7a572ce3edd6d476191fbfe92c9c1986e009b34" "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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded ferris-gc-proc-macro v0.1.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-86/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-86/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" "+a7a572ce3edd6d476191fbfe92c9c1986e009b34" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 06d5b9bfcade895aac3a995362814e9bbf5b389771f14456d49bbd6bcaaef37b
[INFO] running `Command { std: "docker" "start" "-a" "06d5b9bfcade895aac3a995362814e9bbf5b389771f14456d49bbd6bcaaef37b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "06d5b9bfcade895aac3a995362814e9bbf5b389771f14456d49bbd6bcaaef37b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "06d5b9bfcade895aac3a995362814e9bbf5b389771f14456d49bbd6bcaaef37b", kill_on_drop: false }`
[INFO] [stdout] 06d5b9bfcade895aac3a995362814e9bbf5b389771f14456d49bbd6bcaaef37b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-86/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-86/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" "+a7a572ce3edd6d476191fbfe92c9c1986e009b34" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] dbf77b848eb4ac7c9c1011c2dc0698f27e850cb5dc450cf93f0ce3391fa8755d
[INFO] running `Command { std: "docker" "start" "-a" "dbf77b848eb4ac7c9c1011c2dc0698f27e850cb5dc450cf93f0ce3391fa8755d", kill_on_drop: false }`
[INFO] [stderr] Copying to /tmp/fixit
[INFO] [stderr] Running `cargo fix --edition`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling syn v1.0.75
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking ferris-gc v0.1.5 (/tmp/fixit)
[INFO] [stderr]    Migrating src/lib.rs from 2018 edition to 2021
[INFO] [stderr]        Fixed src/gc.rs (1 fix)
[INFO] [stderr]        Fixed src/default_trace.rs (5 fixes)
[INFO] [stdout] warning: unused import: `std::borrow::BorrowMut`
[INFO] [stdout]  --> src/gc.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::borrow::BorrowMut;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::hash::Hasher`
[INFO] [stdout]   --> src/gc/sync.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 | use std::hash::Hasher;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/gc.rs:384:32
[INFO] [stdout]     |
[INFO] [stdout] 382 |         LOCAL_GC_STRATEGY.with(|strategy| unsafe {
[INFO] [stdout]     |                                           ------ because it's nested under this `unsafe` block
[INFO] [stdout] 383 |             if !strategy.borrow().is_active() {
[INFO] [stdout] 384 |                 let strategy = unsafe { &mut *strategy.as_ptr() };
[INFO] [stdout]     |                                ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_unsafe)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/gc/sync.rs:519:36
[INFO] [stdout]     |
[INFO] [stdout] 519 |         let (tracer_thin_ptr, _) = unsafe { transmute::<_, (*const (), *const ())>(tracer) };
[INFO] [stdout]     |                                    ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `collect_all`
[INFO] [stdout]    --> src/gc/sync.rs:569:15
[INFO] [stdout]     |
[INFO] [stdout] 569 |     unsafe fn collect_all(&self) {
[INFO] [stdout]     |               ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `collect_all`
[INFO] [stdout]    --> src/gc.rs:602:15
[INFO] [stdout]     |
[INFO] [stdout] 602 |     unsafe fn collect_all(&self) {
[INFO] [stdout]     |               ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused boxed `FnMut` trait object that must be used
[INFO] [stdout]    --> src/gc.rs:666:9
[INFO] [stdout]     |
[INFO] [stdout] 666 |         self.start_func.replace(Box::new(start_fn));
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: closures are lazy and do nothing unless called
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused boxed `FnMut` trait object that must be used
[INFO] [stdout]    --> src/gc.rs:667:9
[INFO] [stdout]     |
[INFO] [stdout] 667 |         self.stop_func.replace(Box::new(stop_fn));
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: closures are lazy and do nothing unless called
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/basic_gc_strategy.rs:34:13
[INFO] [stdout]    |
[INFO] [stdout] 34 |             bthread.join();
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 9 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling ferris-gc-proc-macro v0.1.2
[INFO] [stdout] warning: unused import: `std::borrow::BorrowMut`
[INFO] [stdout]  --> src/gc.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::borrow::BorrowMut;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::hash::Hasher`
[INFO] [stdout]   --> src/gc/sync.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 | use std::hash::Hasher;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `one` is assigned to, but never used
[INFO] [stdout]    --> src/gc/sync.rs:707:17
[INFO] [stdout]     |
[INFO] [stdout] 707 |         let mut one = Gc::new(1);
[INFO] [stdout]     |                 ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout]     = note: consider using `_one` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `one` is never read
[INFO] [stdout]    --> src/gc/sync.rs:708:9
[INFO] [stdout]     |
[INFO] [stdout] 708 |         one = Gc::new(2);
[INFO] [stdout]     |         ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `one` is assigned to, but never used
[INFO] [stdout]    --> src/gc/sync.rs:715:17
[INFO] [stdout]     |
[INFO] [stdout] 715 |         let mut one = Gc::new(1);
[INFO] [stdout]     |                 ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: consider using `_one` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `one` is never read
[INFO] [stdout]    --> src/gc/sync.rs:716:9
[INFO] [stdout]     |
[INFO] [stdout] 716 |         one = Gc::new(2);
[INFO] [stdout]     |         ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `one` is assigned to, but never used
[INFO] [stdout]    --> src/gc/sync.rs:724:21
[INFO] [stdout]     |
[INFO] [stdout] 724 |             let mut one = Gc::new(1);
[INFO] [stdout]     |                     ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: consider using `_one` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `one` is never read
[INFO] [stdout]    --> src/gc/sync.rs:725:13
[INFO] [stdout]     |
[INFO] [stdout] 725 |             one = Gc::new(2);
[INFO] [stdout]     |             ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `one` is assigned to, but never used
[INFO] [stdout]    --> src/gc.rs:741:17
[INFO] [stdout]     |
[INFO] [stdout] 741 |         let mut one = Gc::new(1);
[INFO] [stdout]     |                 ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: consider using `_one` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `one` is never read
[INFO] [stdout]    --> src/gc.rs:742:9
[INFO] [stdout]     |
[INFO] [stdout] 742 |         one = Gc::new(2);
[INFO] [stdout]     |         ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `one` is assigned to, but never used
[INFO] [stdout]    --> src/gc.rs:750:17
[INFO] [stdout]     |
[INFO] [stdout] 750 |         let mut one = Gc::new(1);
[INFO] [stdout]     |                 ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: consider using `_one` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `one` is never read
[INFO] [stdout]    --> src/gc.rs:751:9
[INFO] [stdout]     |
[INFO] [stdout] 751 |         one = Gc::new(2);
[INFO] [stdout]     |         ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `one` is assigned to, but never used
[INFO] [stdout]    --> src/gc.rs:761:21
[INFO] [stdout]     |
[INFO] [stdout] 761 |             let mut one = Gc::new(1);
[INFO] [stdout]     |                     ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: consider using `_one` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `one` is never read
[INFO] [stdout]    --> src/gc.rs:762:13
[INFO] [stdout]     |
[INFO] [stdout] 762 |             one = Gc::new(2);
[INFO] [stdout]     |             ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/gc.rs:384:32
[INFO] [stdout]     |
[INFO] [stdout] 382 |         LOCAL_GC_STRATEGY.with(|strategy| unsafe {
[INFO] [stdout]     |                                           ------ because it's nested under this `unsafe` block
[INFO] [stdout] 383 |             if !strategy.borrow().is_active() {
[INFO] [stdout] 384 |                 let strategy = unsafe { &mut *strategy.as_ptr() };
[INFO] [stdout]     |                                ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_unsafe)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/gc/sync.rs:519:36
[INFO] [stdout]     |
[INFO] [stdout] 519 |         let (tracer_thin_ptr, _) = unsafe { transmute::<_, (*const (), *const ())>(tracer) };
[INFO] [stdout]     |                                    ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `collect_all`
[INFO] [stdout]    --> src/gc/sync.rs:569:15
[INFO] [stdout]     |
[INFO] [stdout] 569 |     unsafe fn collect_all(&self) {
[INFO] [stdout]     |               ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `collect_all`
[INFO] [stdout]    --> src/gc.rs:602:15
[INFO] [stdout]     |
[INFO] [stdout] 602 |     unsafe fn collect_all(&self) {
[INFO] [stdout]     |               ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused boxed `FnMut` trait object that must be used
[INFO] [stdout]    --> src/gc.rs:666:9
[INFO] [stdout]     |
[INFO] [stdout] 666 |         self.start_func.replace(Box::new(start_fn));
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: closures are lazy and do nothing unless called
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused boxed `FnMut` trait object that must be used
[INFO] [stdout]    --> src/gc.rs:667:9
[INFO] [stdout]     |
[INFO] [stdout] 667 |         self.stop_func.replace(Box::new(stop_fn));
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: closures are lazy and do nothing unless called
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/basic_gc_strategy.rs:34:13
[INFO] [stdout]    |
[INFO] [stdout] 34 |             bthread.join();
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 21 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 19.17s
[INFO] [stderr] Running `cargo check` to verify 2021
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking ferris-gc v0.1.5 (/tmp/fixit)
[INFO] [stdout] warning: unused import: `std::borrow::BorrowMut`
[INFO] [stdout]  --> src/gc.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::borrow::BorrowMut;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::hash::Hasher`
[INFO] [stdout]   --> src/gc/sync.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 | use std::hash::Hasher;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::borrow::BorrowMut`
[INFO] [stdout]  --> src/gc.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::borrow::BorrowMut;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::hash::Hasher`
[INFO] [stdout]   --> src/gc/sync.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 | use std::hash::Hasher;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `one` is assigned to, but never used
[INFO] [stdout]    --> src/gc/sync.rs:707:17
[INFO] [stdout]     |
[INFO] [stdout] 707 |         let mut one = Gc::new(1);
[INFO] [stdout]     |                 ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout]     = note: consider using `_one` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `one` is never read
[INFO] [stdout]    --> src/gc/sync.rs:708:9
[INFO] [stdout]     |
[INFO] [stdout] 708 |         one = Gc::new(2);
[INFO] [stdout]     |         ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `one` is assigned to, but never used
[INFO] [stdout]    --> src/gc/sync.rs:715:17
[INFO] [stdout]     |
[INFO] [stdout] 715 |         let mut one = Gc::new(1);
[INFO] [stdout]     |                 ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: consider using `_one` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `one` is never read
[INFO] [stdout]    --> src/gc/sync.rs:716:9
[INFO] [stdout]     |
[INFO] [stdout] 716 |         one = Gc::new(2);
[INFO] [stdout]     |         ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `one` is assigned to, but never used
[INFO] [stdout]    --> src/gc/sync.rs:724:21
[INFO] [stdout]     |
[INFO] [stdout] 724 |             let mut one = Gc::new(1);
[INFO] [stdout]     |                     ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: consider using `_one` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `one` is never read
[INFO] [stdout]    --> src/gc/sync.rs:725:13
[INFO] [stdout]     |
[INFO] [stdout] 725 |             one = Gc::new(2);
[INFO] [stdout]     |             ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `one` is assigned to, but never used
[INFO] [stdout]    --> src/gc.rs:741:17
[INFO] [stdout]     |
[INFO] [stdout] 741 |         let mut one = Gc::new(1);
[INFO] [stdout]     |                 ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: consider using `_one` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `one` is never read
[INFO] [stdout]    --> src/gc.rs:742:9
[INFO] [stdout]     |
[INFO] [stdout] 742 |         one = Gc::new(2);
[INFO] [stdout]     |         ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `one` is assigned to, but never used
[INFO] [stdout]    --> src/gc.rs:750:17
[INFO] [stdout]     |
[INFO] [stdout] 750 |         let mut one = Gc::new(1);
[INFO] [stdout]     |                 ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: consider using `_one` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `one` is never read
[INFO] [stdout]    --> src/gc.rs:751:9
[INFO] [stdout]     |
[INFO] [stdout] 751 |         one = Gc::new(2);
[INFO] [stdout]     |         ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `one` is assigned to, but never used
[INFO] [stdout]    --> src/gc.rs:761:21
[INFO] [stdout]     |
[INFO] [stdout] 761 |             let mut one = Gc::new(1);
[INFO] [stdout]     |                     ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: consider using `_one` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `one` is never read
[INFO] [stdout]    --> src/gc.rs:762:13
[INFO] [stdout]     |
[INFO] [stdout] 762 |             one = Gc::new(2);
[INFO] [stdout]     |             ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/gc.rs:384:32
[INFO] [stdout]     |
[INFO] [stdout] 382 |         LOCAL_GC_STRATEGY.with(|strategy| unsafe {
[INFO] [stdout]     |                                           ------ because it's nested under this `unsafe` block
[INFO] [stdout] 383 |             if !strategy.borrow().is_active() {
[INFO] [stdout] 384 |                 let strategy = unsafe { &mut *strategy.as_ptr() };
[INFO] [stdout]     |                                ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_unsafe)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/gc/sync.rs:519:36
[INFO] [stdout]     |
[INFO] [stdout] 519 |         let (tracer_thin_ptr, _) = unsafe { transmute::<_, (*const (), *const ())>(tracer) };
[INFO] [stdout]     |                                    ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/gc.rs:384:32
[INFO] [stdout]     |
[INFO] [stdout] 382 |         LOCAL_GC_STRATEGY.with(|strategy| unsafe {
[INFO] [stdout]     |                                           ------ because it's nested under this `unsafe` block
[INFO] [stdout] 383 |             if !strategy.borrow().is_active() {
[INFO] [stdout] 384 |                 let strategy = unsafe { &mut *strategy.as_ptr() };
[INFO] [stdout]     |                                ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_unsafe)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `collect_all`
[INFO] [stdout]    --> src/gc/sync.rs:569:15
[INFO] [stdout]     |
[INFO] [stdout] 569 |     unsafe fn collect_all(&self) {
[INFO] [stdout]     |               ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `collect_all`
[INFO] [stdout]    --> src/gc.rs:602:15
[INFO] [stdout]     |
[INFO] [stdout] 602 |     unsafe fn collect_all(&self) {
[INFO] [stdout]     |               ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/gc/sync.rs:519:36
[INFO] [stdout]     |
[INFO] [stdout] 519 |         let (tracer_thin_ptr, _) = unsafe { transmute::<_, (*const (), *const ())>(tracer) };
[INFO] [stdout]     |                                    ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `collect_all`
[INFO] [stdout]    --> src/gc/sync.rs:569:15
[INFO] [stdout]     |
[INFO] [stdout] 569 |     unsafe fn collect_all(&self) {
[INFO] [stdout]     |               ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `collect_all`
[INFO] [stdout]    --> src/gc.rs:602:15
[INFO] [stdout]     |
[INFO] [stdout] 602 |     unsafe fn collect_all(&self) {
[INFO] [stdout]     |               ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused boxed `FnMut` trait object that must be used
[INFO] [stdout]    --> src/gc.rs:666:9
[INFO] [stdout]     |
[INFO] [stdout] 666 |         self.start_func.replace(Box::new(start_fn));
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: closures are lazy and do nothing unless called
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused boxed `FnMut` trait object that must be used
[INFO] [stdout]    --> src/gc.rs:667:9
[INFO] [stdout]     |
[INFO] [stdout] 667 |         self.stop_func.replace(Box::new(stop_fn));
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: closures are lazy and do nothing unless called
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/basic_gc_strategy.rs:34:13
[INFO] [stdout]    |
[INFO] [stdout] 34 |             bthread.join();
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused boxed `FnMut` trait object that must be used
[INFO] [stdout]    --> src/gc.rs:666:9
[INFO] [stdout]     |
[INFO] [stdout] 666 |         self.start_func.replace(Box::new(start_fn));
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: closures are lazy and do nothing unless called
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused boxed `FnMut` trait object that must be used
[INFO] [stdout]    --> src/gc.rs:667:9
[INFO] [stdout]     |
[INFO] [stdout] 667 |         self.stop_func.replace(Box::new(stop_fn));
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: closures are lazy and do nothing unless called
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/basic_gc_strategy.rs:34:13
[INFO] [stdout]    |
[INFO] [stdout] 34 |             bthread.join();
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 9 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 21 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.96s
[INFO] running `Command { std: "docker" "inspect" "dbf77b848eb4ac7c9c1011c2dc0698f27e850cb5dc450cf93f0ce3391fa8755d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dbf77b848eb4ac7c9c1011c2dc0698f27e850cb5dc450cf93f0ce3391fa8755d", kill_on_drop: false }`
[INFO] [stdout] dbf77b848eb4ac7c9c1011c2dc0698f27e850cb5dc450cf93f0ce3391fa8755d