[INFO] updating cached repository https://github.com/reem/rust-n-queens
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 9a6e9c463cc3e0d8bd7abc3dc818499cfc097ffa
[INFO] checking reem/rust-n-queens against master#bf1f2eedda4fa02b7c9347dd849ed73ddd43dedc for pr-70917
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Freem%2Frust-n-queens" "/workspace/builds/worker-3/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/reem/rust-n-queens on toolchain bf1f2eedda4fa02b7c9347dd849ed73ddd43dedc
[INFO] running `"/workspace/cargo-home/bin/cargo" "+bf1f2eedda4fa02b7c9347dd849ed73ddd43dedc" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/reem/rust-n-queens
[INFO] finished tweaking git repo https://github.com/reem/rust-n-queens
[INFO] tweaked toml for git repo https://github.com/reem/rust-n-queens written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/reem/rust-n-queens already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+bf1f2eedda4fa02b7c9347dd849ed73ddd43dedc" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+bf1f2eedda4fa02b7c9347dd849ed73ddd43dedc" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 394212d56496b73ee77aaae63e65eb37ee2d0d8b6d1a71a2150cfa0170a5bf3a
[INFO] running `"docker" "start" "-a" "394212d56496b73ee77aaae63e65eb37ee2d0d8b6d1a71a2150cfa0170a5bf3a"`
[INFO] [stderr]     Checking nqueens v1.0.0 (/opt/rustwide/workdir)
[INFO] [stderr] error: expected one of `)`, `,`, `.`, `?`, or an operator, found `{`
[INFO] [stderr]    --> src/main.rs:120:22
[INFO] [stderr]     |
[INFO] [stderr] 120 |         spawn(proc() {
[INFO] [stderr]     |                     -^ expected one of `)`, `,`, `.`, `?`, or an operator
[INFO] [stderr]     |                     |
[INFO] [stderr]     |                     help: missing `,`
[INFO] [stderr] 
[INFO] [stderr] error: invalid suffix `u` for integer literal
[INFO] [stderr]    --> src/main.rs:129:23
[INFO] [stderr]     |
[INFO] [stderr] 129 |     let mut results = 0u;
[INFO] [stderr]     |                       ^^ invalid suffix `u`
[INFO] [stderr]     |
[INFO] [stderr]     = help: the suffix must be one of the integral types (`u32`, `isize`, etc)
[INFO] [stderr] 
[INFO] [stderr] error: invalid suffix `u` for integer literal
[INFO] [stderr]    --> src/main.rs:141:25
[INFO] [stderr]     |
[INFO] [stderr] 141 |     for num in range(0, 9u) {
[INFO] [stderr]     |                         ^^ invalid suffix `u`
[INFO] [stderr]     |
[INFO] [stderr]     = help: the suffix must be one of the integral types (`u32`, `isize`, etc)
[INFO] [stderr] 
[INFO] [stderr] error: invalid suffix `u` for integer literal
[INFO] [stderr]    --> src/main.rs:149:25
[INFO] [stderr]     |
[INFO] [stderr] 149 |     for num in range(0, 9u) {
[INFO] [stderr]     |                         ^^ invalid suffix `u`
[INFO] [stderr]     |
[INFO] [stderr]     = help: the suffix must be one of the integral types (`u32`, `isize`, etc)
[INFO] [stderr] 
[INFO] [stderr] error: expected one of `)`, `,`, `.`, `?`, or an operator, found `{`
[INFO] [stderr]    --> src/main.rs:120:22
[INFO] [stderr]     |
[INFO] [stderr] 120 |         spawn(proc() {
[INFO] [stderr]     |                     -^ expected one of `)`, `,`, `.`, `?`, or an operator
[INFO] [stderr]     |                     |
[INFO] [stderr]     |                     help: missing `,`
[INFO] [stderr] 
[INFO] [stderr] error: invalid suffix `u` for integer literal
[INFO] [stderr]    --> src/main.rs:129:23
[INFO] [stderr]     |
[INFO] [stderr] 129 |     let mut results = 0u;
[INFO] [stderr]     |                       ^^ invalid suffix `u`
[INFO] [stderr]     |
[INFO] [stderr]     = help: the suffix must be one of the integral types (`u32`, `isize`, etc)
[INFO] [stderr] 
[INFO] [stderr] error: invalid suffix `u` for integer literal
[INFO] [stderr]    --> src/main.rs:141:25
[INFO] [stderr]     |
[INFO] [stderr] 141 |     for num in range(0, 9u) {
[INFO] [stderr]     |                         ^^ invalid suffix `u`
[INFO] [stderr]     |
[INFO] [stderr]     = help: the suffix must be one of the integral types (`u32`, `isize`, etc)
[INFO] [stderr] 
[INFO] [stderr] error: invalid suffix `u` for integer literal
[INFO] [stderr]    --> src/main.rs:149:25
[INFO] [stderr]     |
[INFO] [stderr] 149 |     for num in range(0, 9u) {
[INFO] [stderr]     |                         ^^ invalid suffix `u`
[INFO] [stderr]     |
[INFO] [stderr]     = help: the suffix must be one of the integral types (`u32`, `isize`, etc)
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]   --> src/main.rs:21:24
[INFO] [stderr]    |
[INFO] [stderr] 21 | fn n_queens(n: i32) -> uint {
[INFO] [stderr]    |                        ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]   --> src/main.rs:23:39
[INFO] [stderr]    |
[INFO] [stderr] 23 |     return n_queens_helper((1 << n as uint) -1, 0, 0, 0);
[INFO] [stderr]    |                                       ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]   --> src/main.rs:45:87
[INFO] [stderr]    |
[INFO] [stderr] 45 | fn n_queens_helper(all_ones: i32, left_diags: i32, columns: i32, right_diags: i32) -> uint {
[INFO] [stderr]    |                                                                                       ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]    --> src/main.rs:100:50
[INFO] [stderr]     |
[INFO] [stderr] 100 |     return solutions + ((columns == all_ones) as uint)
[INFO] [stderr]     |                                                  ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]    --> src/main.rs:108:33
[INFO] [stderr]     |
[INFO] [stderr] 108 | fn parallel_n_queens(n: i32) -> uint {
[INFO] [stderr]     |                                 ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]    --> src/main.rs:109:31
[INFO] [stderr]     |
[INFO] [stderr] 109 |     let all_ones = (1 << n as uint) - 1;
[INFO] [stderr]     |                               ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0425]: cannot find function `channel` in this scope
[INFO] [stderr]    --> src/main.rs:115:20
[INFO] [stderr]     |
[INFO] [stderr] 115 |     let (tx, rx) = channel();
[INFO] [stderr]     |                    ^^^^^^^ not found in this scope
[INFO] [stderr]     |
[INFO] [stderr] help: possible candidate is found in another module, you can import it into scope
[INFO] [stderr]     |
[INFO] [stderr] 4   | use std::sync::mpsc::channel;
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] error[E0425]: cannot find function `spawn` in this scope
[INFO] [stderr]    --> src/main.rs:120:9
[INFO] [stderr]     |
[INFO] [stderr] 120 |         spawn(proc() {
[INFO] [stderr]     |         ^^^^^ not found in this scope
[INFO] [stderr]     |
[INFO] [stderr] help: possible candidate is found in another module, you can import it into scope
[INFO] [stderr]     |
[INFO] [stderr] 4   | use std::thread::spawn;
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] error[E0425]: cannot find function `proc` in this scope
[INFO] [stderr]    --> src/main.rs:120:15
[INFO] [stderr]     |
[INFO] [stderr] 120 |         spawn(proc() {
[INFO] [stderr]     |               ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]    --> src/main.rs:130:38
[INFO] [stderr]     |
[INFO] [stderr] 130 |     for value in rx.iter().take(n as uint) {
[INFO] [stderr]     |                                      ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]    --> src/main.rs:133:48
[INFO] [stderr]     |
[INFO] [stderr] 133 |     return results + ((columns == all_ones) as uint)
[INFO] [stderr]     |                                                ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error: use of unstable library feature 'test': `bench` is a part of custom test frameworks which are unstable
[INFO] [stderr]    --> src/main.rs:154:3
[INFO] [stderr]     |
[INFO] [stderr] 154 | #[bench]
[INFO] [stderr]     |   ^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[deny(soft_unstable)]` on by default
[INFO] [stderr]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stderr]     = note: for more information, see issue #64266 <https://github.com/rust-lang/rust/issues/64266>
[INFO] [stderr] 
[INFO] [stderr] error: use of unstable library feature 'test': `bench` is a part of custom test frameworks which are unstable
[INFO] [stderr]    --> src/main.rs:159:3
[INFO] [stderr]     |
[INFO] [stderr] 159 | #[bench]
[INFO] [stderr]     |   ^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stderr]     = note: for more information, see issue #64266 <https://github.com/rust-lang/rust/issues/64266>
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around function argument
[INFO] [stderr]   --> src/main.rs:90:13
[INFO] [stderr]    |
[INFO] [stderr] 90 |             (columns | spot),
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around function argument
[INFO] [stderr]    --> src/main.rs:124:17
[INFO] [stderr]     |
[INFO] [stderr] 124 |                 (columns | spot),
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 17 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0412, E0425.
[INFO] [stderr] For more information about an error, try `rustc --explain E0412`.
[INFO] [stderr] error: could not compile `nqueens`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: invalid suffix `u` for integer literal
[INFO] [stderr]    --> src/main.rs:140:47
[INFO] [stderr]     |
[INFO] [stderr] 140 |     let real = vec!(1, 1, 0, 0, 2, 10, 4, 40, 92u);
[INFO] [stderr]     |                                               ^^^ invalid suffix `u`
[INFO] [stderr]     |
[INFO] [stderr]     = help: the suffix must be one of the integral types (`u32`, `isize`, etc)
[INFO] [stderr] 
[INFO] [stderr] error: invalid suffix `u` for integer literal
[INFO] [stderr]    --> src/main.rs:148:47
[INFO] [stderr]     |
[INFO] [stderr] 148 |     let real = vec!(1, 1, 0, 0, 2, 10, 4, 40, 92u);
[INFO] [stderr]     |                                               ^^^ invalid suffix `u`
[INFO] [stderr]     |
[INFO] [stderr]     = help: the suffix must be one of the integral types (`u32`, `isize`, etc)
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]   --> src/main.rs:21:24
[INFO] [stderr]    |
[INFO] [stderr] 21 | fn n_queens(n: i32) -> uint {
[INFO] [stderr]    |                        ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]   --> src/main.rs:23:39
[INFO] [stderr]    |
[INFO] [stderr] 23 |     return n_queens_helper((1 << n as uint) -1, 0, 0, 0);
[INFO] [stderr]    |                                       ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]   --> src/main.rs:45:87
[INFO] [stderr]    |
[INFO] [stderr] 45 | fn n_queens_helper(all_ones: i32, left_diags: i32, columns: i32, right_diags: i32) -> uint {
[INFO] [stderr]    |                                                                                       ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]    --> src/main.rs:100:50
[INFO] [stderr]     |
[INFO] [stderr] 100 |     return solutions + ((columns == all_ones) as uint)
[INFO] [stderr]     |                                                  ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]    --> src/main.rs:108:33
[INFO] [stderr]     |
[INFO] [stderr] 108 | fn parallel_n_queens(n: i32) -> uint {
[INFO] [stderr]     |                                 ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]    --> src/main.rs:109:31
[INFO] [stderr]     |
[INFO] [stderr] 109 |     let all_ones = (1 << n as uint) - 1;
[INFO] [stderr]     |                               ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0425]: cannot find function `channel` in this scope
[INFO] [stderr]    --> src/main.rs:115:20
[INFO] [stderr]     |
[INFO] [stderr] 115 |     let (tx, rx) = channel();
[INFO] [stderr]     |                    ^^^^^^^ not found in this scope
[INFO] [stderr]     |
[INFO] [stderr] help: possible candidate is found in another module, you can import it into scope
[INFO] [stderr]     |
[INFO] [stderr] 2   | #[cfg(test)] use std::sync::mpsc::channel;
[INFO] [stderr]     |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0425]: cannot find function `spawn` in this scope
[INFO] [stderr]    --> src/main.rs:120:9
[INFO] [stderr]     |
[INFO] [stderr] 120 |         spawn(proc() {
[INFO] [stderr]     |         ^^^^^ not found in this scope
[INFO] [stderr]     |
[INFO] [stderr] help: possible candidate is found in another module, you can import it into scope
[INFO] [stderr]     |
[INFO] [stderr] 2   | #[cfg(test)] use std::thread::spawn;
[INFO] [stderr]     |              ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0425]: cannot find function `proc` in this scope
[INFO] [stderr]    --> src/main.rs:120:15
[INFO] [stderr]     |
[INFO] [stderr] 120 |         spawn(proc() {
[INFO] [stderr]     |               ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]    --> src/main.rs:130:38
[INFO] [stderr]     |
[INFO] [stderr] 130 |     for value in rx.iter().take(n as uint) {
[INFO] [stderr]     |                                      ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `uint` in this scope
[INFO] [stderr]    --> src/main.rs:133:48
[INFO] [stderr]     |
[INFO] [stderr] 133 |     return results + ((columns == all_ones) as uint)
[INFO] [stderr]     |                                                ^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0425]: cannot find function `range` in this scope
[INFO] [stderr]    --> src/main.rs:141:16
[INFO] [stderr]     |
[INFO] [stderr] 141 |     for num in range(0, 9u) {
[INFO] [stderr]     |                ^^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error[E0425]: cannot find function `range` in this scope
[INFO] [stderr]    --> src/main.rs:149:16
[INFO] [stderr]     |
[INFO] [stderr] 149 |     for num in range(0, 9u) {
[INFO] [stderr]     |                ^^^^^ not found in this scope
[INFO] [stderr] 
[INFO] [stderr] error: use of unstable library feature 'test': `bench` is a part of custom test frameworks which are unstable
[INFO] [stderr]    --> src/main.rs:154:3
[INFO] [stderr]     |
[INFO] [stderr] 154 | #[bench]
[INFO] [stderr]     |   ^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[deny(soft_unstable)]` on by default
[INFO] [stderr]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stderr]     = note: for more information, see issue #64266 <https://github.com/rust-lang/rust/issues/64266>
[INFO] [stderr] 
[INFO] [stderr] error: use of unstable library feature 'test': `bench` is a part of custom test frameworks which are unstable
[INFO] [stderr]    --> src/main.rs:159:3
[INFO] [stderr]     |
[INFO] [stderr] 159 | #[bench]
[INFO] [stderr]     |   ^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stderr]     = note: for more information, see issue #64266 <https://github.com/rust-lang/rust/issues/64266>
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around function argument
[INFO] [stderr]   --> src/main.rs:90:13
[INFO] [stderr]    |
[INFO] [stderr] 90 |             (columns | spot),
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around function argument
[INFO] [stderr]    --> src/main.rs:124:17
[INFO] [stderr]     |
[INFO] [stderr] 124 |                 (columns | spot),
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] error[E0658]: use of unstable library feature 'test'
[INFO] [stderr]  --> src/main.rs:1:14
[INFO] [stderr]   |
[INFO] [stderr] 1 | #[cfg(test)] extern crate test;
[INFO] [stderr]   |              ^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: see issue #50297 <https://github.com/rust-lang/rust/issues/50297> for more information
[INFO] [stderr]   = help: add `#![feature(test)]` to the crate attributes to enable
[INFO] [stderr] 
[INFO] [stderr] error[E0658]: use of unstable library feature 'test'
[INFO] [stderr]  --> src/main.rs:2:18
[INFO] [stderr]   |
[INFO] [stderr] 2 | #[cfg(test)] use test::Bencher;
[INFO] [stderr]   |                  ^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: see issue #50297 <https://github.com/rust-lang/rust/issues/50297> for more information
[INFO] [stderr]   = help: add `#![feature(test)]` to the crate attributes to enable
[INFO] [stderr] 
[INFO] [stderr] error[E0658]: use of unstable library feature 'test'
[INFO] [stderr]    --> src/main.rs:155:27
[INFO] [stderr]     |
[INFO] [stderr] 155 | fn bench_n_queens(b: &mut Bencher) {
[INFO] [stderr]     |                           ^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: see issue #50297 <https://github.com/rust-lang/rust/issues/50297> for more information
[INFO] [stderr]     = help: add `#![feature(test)]` to the crate attributes to enable
[INFO] [stderr] 
[INFO] [stderr] error[E0658]: use of unstable library feature 'test'
[INFO] [stderr]    --> src/main.rs:156:17
[INFO] [stderr]     |
[INFO] [stderr] 156 |     b.iter(|| { test::black_box(n_queens(12)); });
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: see issue #50297 <https://github.com/rust-lang/rust/issues/50297> for more information
[INFO] [stderr]     = help: add `#![feature(test)]` to the crate attributes to enable
[INFO] [stderr] 
[INFO] [stderr] error[E0658]: use of unstable library feature 'test'
[INFO] [stderr]    --> src/main.rs:160:36
[INFO] [stderr]     |
[INFO] [stderr] 160 | fn bench_parallel_n_queens(b: &mut Bencher) {
[INFO] [stderr]     |                                    ^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: see issue #50297 <https://github.com/rust-lang/rust/issues/50297> for more information
[INFO] [stderr]     = help: add `#![feature(test)]` to the crate attributes to enable
[INFO] [stderr] 
[INFO] [stderr] error[E0658]: use of unstable library feature 'test'
[INFO] [stderr]    --> src/main.rs:161:17
[INFO] [stderr]     |
[INFO] [stderr] 161 |     b.iter(|| { test::black_box(parallel_n_queens(12)); });
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: see issue #50297 <https://github.com/rust-lang/rust/issues/50297> for more information
[INFO] [stderr]     = help: add `#![feature(test)]` to the crate attributes to enable
[INFO] [stderr] 
[INFO] [stderr] error[E0658]: use of unstable library feature 'test'
[INFO] [stderr]    --> src/main.rs:156:7
[INFO] [stderr]     |
[INFO] [stderr] 156 |     b.iter(|| { test::black_box(n_queens(12)); });
[INFO] [stderr]     |       ^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: see issue #50297 <https://github.com/rust-lang/rust/issues/50297> for more information
[INFO] [stderr]     = help: add `#![feature(test)]` to the crate attributes to enable
[INFO] [stderr] 
[INFO] [stderr] error[E0658]: use of unstable library feature 'test'
[INFO] [stderr]    --> src/main.rs:161:7
[INFO] [stderr]     |
[INFO] [stderr] 161 |     b.iter(|| { test::black_box(parallel_n_queens(12)); });
[INFO] [stderr]     |       ^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: see issue #50297 <https://github.com/rust-lang/rust/issues/50297> for more information
[INFO] [stderr]     = help: add `#![feature(test)]` to the crate attributes to enable
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 29 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0412, E0425, E0658.
[INFO] [stderr] For more information about an error, try `rustc --explain E0412`.
[INFO] [stderr] error: could not compile `nqueens`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "394212d56496b73ee77aaae63e65eb37ee2d0d8b6d1a71a2150cfa0170a5bf3a"`
[INFO] running `"docker" "rm" "-f" "394212d56496b73ee77aaae63e65eb37ee2d0d8b6d1a71a2150cfa0170a5bf3a"`
[INFO] [stdout] 394212d56496b73ee77aaae63e65eb37ee2d0d8b6d1a71a2150cfa0170a5bf3a
