[INFO] cloning repository https://github.com/playXE/garbage-collector
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/playXE/garbage-collector" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FplayXE%2Fgarbage-collector", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FplayXE%2Fgarbage-collector'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 2972f68c8ed3889bd1b6979aaa37ab395afdb36e
[INFO] checking playXE/garbage-collector against 760e1de835e253bf28bbcbfee38b5e8ed9ffe074 for pr-133502-26
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FplayXE%2Fgarbage-collector" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/playXE/garbage-collector
[INFO] finished tweaking git repo https://github.com/playXE/garbage-collector
[INFO] tweaked toml for git repo https://github.com/playXE/garbage-collector written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/playXE/garbage-collector on toolchain 760e1de835e253bf28bbcbfee38b5e8ed9ffe074
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+760e1de835e253bf28bbcbfee38b5e8ed9ffe074" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/playXE/garbage-collector 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" "+760e1de835e253bf28bbcbfee38b5e8ed9ffe074" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating git repository `https://github.com/zesterer/flume`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded simple_logger v1.6.0
[INFO] [stderr]   Downloaded criterion v0.3.3
[INFO] [stderr]   Downloaded either v1.6.0
[INFO] [stderr]   Downloaded wasm-bindgen-macro v0.2.67
[INFO] [stderr]   Downloaded wasm-bindgen-shared v0.2.67
[INFO] [stderr]   Downloaded wasm-bindgen-macro-support v0.2.67
[INFO] [stderr]   Downloaded oorandom v11.1.2
[INFO] [stderr]   Downloaded tinytemplate v1.1.0
[INFO] [stderr]   Downloaded spinning_top v0.2.2
[INFO] [stderr]   Downloaded half v1.6.0
[INFO] [stderr]   Downloaded wasm-bindgen-backend v0.2.67
[INFO] [stderr]   Downloaded rayon-core v1.8.0
[INFO] [stderr]   Downloaded cc v1.0.59
[INFO] [stderr]   Downloaded serde_derive v1.0.115
[INFO] [stderr]   Downloaded js-sys v0.3.44
[INFO] [stderr]   Downloaded crossbeam-channel v0.4.3
[INFO] [stderr]   Downloaded serde v1.0.115
[INFO] [stderr]   Downloaded chrono v0.4.15
[INFO] [stderr]   Downloaded rayon v1.4.0
[INFO] [stderr]   Downloaded wasm-bindgen v0.2.67
[INFO] [stderr]   Downloaded syn v1.0.39
[INFO] [stderr]   Downloaded bstr v0.2.13
[INFO] [stderr]   Downloaded libc v0.2.76
[INFO] [stderr]   Downloaded web-sys v0.3.44
[INFO] [stderr]   Downloaded csv v1.1.3
[INFO] [stderr]   Downloaded plotters v0.2.15
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:1fa6594d87c8fa7b311925a7a77a16f539833322d9dfba4ce891f211db2f90b1" "sleep" "infinity", kill_on_drop: false }`
[INFO] [stdout] 47eb63f9ea7d78e9cd0cfad65607049550a084cf12db553b52e542de58f0870e
[INFO] running `Command { std: "docker" "start" "47eb63f9ea7d78e9cd0cfad65607049550a084cf12db553b52e542de58f0870e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "47eb63f9ea7d78e9cd0cfad65607049550a084cf12db553b52e542de58f0870e", 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" "47eb63f9ea7d78e9cd0cfad65607049550a084cf12db553b52e542de58f0870e" "/opt/rustwide/cargo-home/bin/cargo" "+760e1de835e253bf28bbcbfee38b5e8ed9ffe074" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "47eb63f9ea7d78e9cd0cfad65607049550a084cf12db553b52e542de58f0870e", 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" "47eb63f9ea7d78e9cd0cfad65607049550a084cf12db553b52e542de58f0870e" "/opt/rustwide/cargo-home/bin/cargo" "+760e1de835e253bf28bbcbfee38b5e8ed9ffe074" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.76
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling serde v1.0.115
[INFO] [stderr]    Compiling memoffset v0.5.5
[INFO] [stderr]    Compiling num-integer v0.1.43
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]    Compiling proc-macro2 v1.0.19
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling log v0.4.11
[INFO] [stderr]    Compiling rayon-core v1.8.0
[INFO] [stderr]    Compiling syn v1.0.39
[INFO] [stderr]    Compiling cast v0.2.3
[INFO] [stderr]     Checking either v1.6.0
[INFO] [stderr]    Compiling cc v1.0.59
[INFO] [stderr]    Compiling serde_json v1.0.57
[INFO] [stderr]     Checking crossbeam-channel v0.4.3
[INFO] [stderr]    Compiling rayon v1.4.0
[INFO] [stderr]    Compiling serde_derive v1.0.115
[INFO] [stderr]     Checking itertools v0.9.0
[INFO] [stderr]     Checking regex-syntax v0.6.18
[INFO] [stderr]     Checking csv-core v0.1.10
[INFO] [stderr]     Checking half v1.6.0
[INFO] [stderr]     Checking once_cell v1.4.1
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking oorandom v11.1.2
[INFO] [stderr]     Checking crossbeam-epoch v0.8.2
[INFO] [stderr]     Checking regex-automata v0.1.9
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling garbage-collector v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking time v0.1.44
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking crossbeam-deque v0.7.3
[INFO] [stderr]     Checking colored v1.9.3
[INFO] [stderr]     Checking plotters v0.2.15
[INFO] [stderr]     Checking regex v1.3.9
[INFO] [stderr]     Checking criterion-plot v0.4.3
[INFO] [stderr]     Checking chrono v0.4.15
[INFO] [stderr]     Checking simple_logger v1.6.0
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]    --> src/accounting/card_table.rs:239:14
[INFO] [stdout]     |
[INFO] [stdout] 239 |             };
[INFO] [stdout]     |              ^ help: remove this semicolon
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(redundant_semicolons)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `super::*`
[INFO] [stdout]   --> src/accounting/stack.rs:90:9
[INFO] [stdout]    |
[INFO] [stdout] 90 |     use super::*;
[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 imports: `MAP_SHARED` and `PROT_EXEC`
[INFO] [stdout]   --> src/mem_map.rs:22:56
[INFO] [stdout]    |
[INFO] [stdout] 22 |     MAP_ANONYMOUS, MAP_FAILED, MAP_FIXED, MAP_PRIVATE, MAP_SHARED, PROT_EXEC, PROT_NONE, PROT_READ,
[INFO] [stdout]    |                                                        ^^^^^^^^^^  ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `utils::*`
[INFO] [stdout]   --> src/spaces/dlmalloc_space.rs:25:5
[INFO] [stdout]    |
[INFO] [stdout] 25 | use utils::*;
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `utils::*`
[INFO] [stdout]  --> src/spaces/spaces.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use utils::*;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `utils::*`
[INFO] [stdout]  --> src/spaces/mod.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use utils::*;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/accounting/stack.rs:122:28
[INFO] [stdout]     |
[INFO] [stdout] 122 |         pub fn push(&self, mut val: Ref<GcBox<()>>) {
[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] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/accounting/stack.rs:123:17
[INFO] [stdout]     |
[INFO] [stdout] 123 |             let mut head = self.head();
[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/accounting/stack.rs:125:21
[INFO] [stdout]     |
[INFO] [stdout] 125 |                 let mut prev = *head;
[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/accounting/stack.rs:136:17
[INFO] [stdout]     |
[INFO] [stdout] 136 |             let mut head = self.head();
[INFO] [stdout]     |                 ----^^^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/locks.rs:131:21
[INFO] [stdout]     |
[INFO] [stdout] 131 |         pub fn lock(&self) -> MutexGuard<T> {
[INFO] [stdout]     |                     ^^^^^     ^^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                     |
[INFO] [stdout]     |                     the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]     = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 131 |         pub fn lock(&self) -> MutexGuard<'_, T> {
[INFO] [stdout]     |                                          +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: direct cast of function item into an integer
[INFO] [stdout]    --> src/spaces/dlmalloc_space.rs:103:37
[INFO] [stdout]     |
[INFO] [stdout] 103 |                 dlmalloc_madvise_cb as usize,
[INFO] [stdout]     |                                     ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(function_casts_as_integer)]` on by default
[INFO] [stdout] help: first cast to a pointer `as *const ()`
[INFO] [stdout]     |
[INFO] [stdout] 103 |                 dlmalloc_madvise_cb as *const () as usize,
[INFO] [stdout]     |                                     ++++++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `val2`
[INFO] [stdout]   --> src/main.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let val2 = Root::new(XX(43));
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_val2`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking bstr v0.2.13
[INFO] [stderr]     Checking serde_cbor v0.11.1
[INFO] [stderr]     Checking csv v1.1.3
[INFO] [stderr]     Checking tinytemplate v1.1.0
[INFO] [stderr]     Checking criterion v0.3.3
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]    --> src/accounting/card_table.rs:239:14
[INFO] [stdout]     |
[INFO] [stdout] 239 |             };
[INFO] [stdout]     |              ^ help: remove this semicolon
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(redundant_semicolons)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `super::*`
[INFO] [stdout]   --> src/accounting/stack.rs:90:9
[INFO] [stdout]    |
[INFO] [stdout] 90 |     use super::*;
[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 variable: `val2`
[INFO] [stdout]   --> src/main.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let val2 = Root::new(XX(43));
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_val2`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `MAP_SHARED` and `PROT_EXEC`
[INFO] [stdout]   --> src/mem_map.rs:22:56
[INFO] [stdout]    |
[INFO] [stdout] 22 |     MAP_ANONYMOUS, MAP_FAILED, MAP_FIXED, MAP_PRIVATE, MAP_SHARED, PROT_EXEC, PROT_NONE, PROT_READ,
[INFO] [stdout]    |                                                        ^^^^^^^^^^  ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `utils::*`
[INFO] [stdout]   --> src/spaces/dlmalloc_space.rs:25:5
[INFO] [stdout]    |
[INFO] [stdout] 25 | use utils::*;
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `utils::*`
[INFO] [stdout]  --> src/spaces/spaces.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use utils::*;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `utils::*`
[INFO] [stdout]  --> src/spaces/mod.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use utils::*;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]   --> benches/gcbench.rs:40:5
[INFO] [stdout]    |
[INFO] [stdout] 40 |     (1 << (i + 1) - 1)
[INFO] [stdout]    |     ^                ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout] 40 -     (1 << (i + 1) - 1)
[INFO] [stdout] 40 +     1 << (i + 1) - 1
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `black_box`
[INFO] [stdout]   --> benches/gcbench.rs:81:17
[INFO] [stdout]    |
[INFO] [stdout] 81 | use criterion::{black_box, criterion_group, criterion_main, Criterion};
[INFO] [stdout]    |                 ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> benches/gcbench.rs:47:29
[INFO] [stdout]    |
[INFO] [stdout] 47 | pub fn populate(depth: i32, mut this_node: &mut Node) {
[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] warning: variable does not need to be mutable
[INFO] [stdout]   --> benches/gcbench.rs:84:9
[INFO] [stdout]    |
[INFO] [stdout] 84 |     let mut inum_iters = num_iters(depth);
[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]   --> benches/gcbench.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |     let mut i = 0;
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> benches/gcbench.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |     let mut i = 0;
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> benches/gcbench.rs:88:9
[INFO] [stdout]    |
[INFO] [stdout] 88 |     for i in 0..inum_iters {
[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]   --> benches/gcbench.rs:95:9
[INFO] [stdout]    |
[INFO] [stdout] 95 |     let mut inum_iters = num_iters(depth);
[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]   --> benches/gcbench.rs:97:9
[INFO] [stdout]    |
[INFO] [stdout] 97 |     let mut i = 0;
[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]    --> benches/gcbench.rs:100:13
[INFO] [stdout]     |
[INFO] [stdout] 100 |         let mut temp_tree = make_tree(depth);
[INFO] [stdout]     |             ----^^^^^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> benches/gcbench.rs:97:9
[INFO] [stdout]    |
[INFO] [stdout] 97 |     let mut i = 0;
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> benches/gcbench.rs:99:9
[INFO] [stdout]    |
[INFO] [stdout] 99 |     for i in 0..inum_iters {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `temp_tree`
[INFO] [stdout]    --> benches/gcbench.rs:100:13
[INFO] [stdout]     |
[INFO] [stdout] 100 |         let mut temp_tree = make_tree(depth);
[INFO] [stdout]     |             ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_temp_tree`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> benches/gcbench.rs:203:31
[INFO] [stdout]     |
[INFO] [stdout] 203 | pub fn rcpopulate(depth: i32, mut this_node: &mut RCNode) {
[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]    --> benches/gcbench.rs:235:9
[INFO] [stdout]     |
[INFO] [stdout] 235 |     let mut inum_iters = num_iters(depth);
[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]    --> benches/gcbench.rs:237:9
[INFO] [stdout]     |
[INFO] [stdout] 237 |     let mut i = 0;
[INFO] [stdout]     |         ----^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]    --> benches/gcbench.rs:237:9
[INFO] [stdout]     |
[INFO] [stdout] 237 |     let mut i = 0;
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]    --> benches/gcbench.rs:239:9
[INFO] [stdout]     |
[INFO] [stdout] 239 |     for i in 0..inum_iters {
[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]    --> benches/gcbench.rs:246:9
[INFO] [stdout]     |
[INFO] [stdout] 246 |     let mut inum_iters = num_iters(depth);
[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]    --> benches/gcbench.rs:248:9
[INFO] [stdout]     |
[INFO] [stdout] 248 |     let mut i = 0;
[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]    --> benches/gcbench.rs:251:13
[INFO] [stdout]     |
[INFO] [stdout] 251 |         let mut temp_tree = rcmake_tree(depth);
[INFO] [stdout]     |             ----^^^^^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]    --> benches/gcbench.rs:248:9
[INFO] [stdout]     |
[INFO] [stdout] 248 |     let mut i = 0;
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]    --> benches/gcbench.rs:250:9
[INFO] [stdout]     |
[INFO] [stdout] 250 |     for i in 0..inum_iters {
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `temp_tree`
[INFO] [stdout]    --> benches/gcbench.rs:251:13
[INFO] [stdout]     |
[INFO] [stdout] 251 |         let mut temp_tree = rcmake_tree(depth);
[INFO] [stdout]     |             ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_temp_tree`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `i` and `j` are never read
[INFO] [stdout]  --> benches/gcbench.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct Node {
[INFO] [stdout]   |            ---- fields in this struct
[INFO] [stdout] 4 |     i: i32,
[INFO] [stdout]   |     ^
[INFO] [stdout] 5 |     j: i32,
[INFO] [stdout]   |     ^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `DEPTH` is never used
[INFO] [stdout]   --> benches/gcbench.rs:80:7
[INFO] [stdout]    |
[INFO] [stdout] 80 | const DEPTH: i32 = 6;
[INFO] [stdout]    |       ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/accounting/stack.rs:122:28
[INFO] [stdout]     |
[INFO] [stdout] 122 |         pub fn push(&self, mut val: Ref<GcBox<()>>) {
[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] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/accounting/stack.rs:123:17
[INFO] [stdout]     |
[INFO] [stdout] 123 |             let mut head = self.head();
[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/accounting/stack.rs:125:21
[INFO] [stdout]     |
[INFO] [stdout] 125 |                 let mut prev = *head;
[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/accounting/stack.rs:136:17
[INFO] [stdout]     |
[INFO] [stdout] 136 |             let mut head = self.head();
[INFO] [stdout]     |                 ----^^^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/locks.rs:131:21
[INFO] [stdout]     |
[INFO] [stdout] 131 |         pub fn lock(&self) -> MutexGuard<T> {
[INFO] [stdout]     |                     ^^^^^     ^^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                     |
[INFO] [stdout]     |                     the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]     = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 131 |         pub fn lock(&self) -> MutexGuard<'_, T> {
[INFO] [stdout]     |                                          +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: direct cast of function item into an integer
[INFO] [stdout]    --> src/spaces/dlmalloc_space.rs:103:37
[INFO] [stdout]     |
[INFO] [stdout] 103 |                 dlmalloc_madvise_cb as usize,
[INFO] [stdout]     |                                     ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(function_casts_as_integer)]` on by default
[INFO] [stdout] help: first cast to a pointer `as *const ()`
[INFO] [stdout]     |
[INFO] [stdout] 103 |                 dlmalloc_madvise_cb as *const () as usize,
[INFO] [stdout]     |                                     ++++++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 15.53s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: criterion v0.3.3
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 10`
[INFO] running `Command { std: "docker" "inspect" "47eb63f9ea7d78e9cd0cfad65607049550a084cf12db553b52e542de58f0870e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "47eb63f9ea7d78e9cd0cfad65607049550a084cf12db553b52e542de58f0870e", kill_on_drop: false }`
[INFO] [stdout] 47eb63f9ea7d78e9cd0cfad65607049550a084cf12db553b52e542de58f0870e
