[INFO] cloning repository https://github.com/csreid/nqueens-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/csreid/nqueens-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcsreid%2Fnqueens-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcsreid%2Fnqueens-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 5d80a29371cad247c2e6d20a82b62f12dde864d3
[INFO] testing csreid/nqueens-rs against 1.75.0 for beta-1.76-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcsreid%2Fnqueens-rs" "/workspace/builds/worker-5-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/csreid/nqueens-rs on toolchain 1.75.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/csreid/nqueens-rs
[INFO] finished tweaking git repo https://github.com/csreid/nqueens-rs
[INFO] tweaked toml for git repo https://github.com/csreid/nqueens-rs written to /workspace/builds/worker-5-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/csreid/nqueens-rs 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" "+1.75.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ba1fa5d7c6924190c29d5609a241c14a0a226e196b0c9ca6e2c97e2c0b0cdd3a
[INFO] running `Command { std: "docker" "start" "-a" "ba1fa5d7c6924190c29d5609a241c14a0a226e196b0c9ca6e2c97e2c0b0cdd3a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ba1fa5d7c6924190c29d5609a241c14a0a226e196b0c9ca6e2c97e2c0b0cdd3a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ba1fa5d7c6924190c29d5609a241c14a0a226e196b0c9ca6e2c97e2c0b0cdd3a", kill_on_drop: false }`
[INFO] [stdout] ba1fa5d7c6924190c29d5609a241c14a0a226e196b0c9ca6e2c97e2c0b0cdd3a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0ebdccdfc852f21c58c31fcb00786ee41bc7dfe12a7f9727a4a34919e8582bee
[INFO] running `Command { std: "docker" "start" "-a" "0ebdccdfc852f21c58c31fcb00786ee41bc7dfe12a7f9727a4a34919e8582bee", kill_on_drop: false }`
[INFO] [stderr]    Compiling num-traits v0.2.6
[INFO] [stderr]    Compiling num-integer v0.1.39
[INFO] [stderr]    Compiling libc v0.2.43
[INFO] [stderr]    Compiling rustc-serialize v0.3.24
[INFO] [stderr]    Compiling num-iter v0.1.37
[INFO] [stderr]    Compiling rand v0.4.3
[INFO] [stderr]    Compiling num-bigint v0.1.44
[INFO] [stderr]    Compiling num-complex v0.1.43
[INFO] [stderr]    Compiling num-rational v0.1.42
[INFO] [stderr]    Compiling num v0.1.42
[INFO] [stderr]    Compiling stopwatch v0.0.7
[INFO] [stderr]    Compiling nqueens-rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:118:12
[INFO] [stdout]     |
[INFO] [stdout] 118 |         for i in (0..=N) {
[INFO] [stdout]     |                  ^     ^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout] 118 -         for i in (0..=N) {
[INFO] [stdout] 118 +         for i in 0..=N {
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:119:13
[INFO] [stdout]     |
[INFO] [stdout] 119 |             for j in (0..=N) {
[INFO] [stdout]     |                      ^     ^
[INFO] [stdout]     |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout] 119 -             for j in (0..=N) {
[INFO] [stdout] 119 +             for j in 0..=N {
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:182:12
[INFO] [stdout]     |
[INFO] [stdout] 182 |         for i in (0..N) {
[INFO] [stdout]     |                  ^    ^
[INFO] [stdout]     |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout] 182 -         for i in (0..N) {
[INFO] [stdout] 182 +         for i in 0..N {
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:183:13
[INFO] [stdout]     |
[INFO] [stdout] 183 |             for j in (0..N) {
[INFO] [stdout]     |                      ^    ^
[INFO] [stdout]     |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout] 183 -             for j in (0..N) {
[INFO] [stdout] 183 +             for j in 0..N {
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]    --> src/main.rs:245:13
[INFO] [stdout]     |
[INFO] [stdout] 245 |     let time = (sw.elapsed_ms() as f64);
[INFO] [stdout]     |                ^                      ^
[INFO] [stdout]     |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout] 245 -     let time = (sw.elapsed_ms() as f64);
[INFO] [stdout] 245 +     let time = sw.elapsed_ms() as f64;
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]    --> src/main.rs:118:7
[INFO] [stdout]     |
[INFO] [stdout] 118 |         for i in (0..=N) {
[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: `children`
[INFO] [stdout]    --> src/main.rs:219:7
[INFO] [stdout]     |
[INFO] [stdout] 219 |         let children = self.children();
[INFO] [stdout]     |             ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_children`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `n_queens_bestfs` is never used
[INFO] [stdout]    --> src/main.rs:193:5
[INFO] [stdout]     |
[INFO] [stdout] 104 | impl Board {
[INFO] [stdout]     | ---------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 193 |     fn n_queens_bestfs(&self, n:i32) -> (Board, i32) {
[INFO] [stdout]     |        ^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:78:4
[INFO] [stdout]    |
[INFO] [stdout] 78 |             write!(f, "+---");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:81:3
[INFO] [stdout]    |
[INFO] [stdout] 81 |         write!(f, "+\n");
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:86:6
[INFO] [stdout]    |
[INFO] [stdout] 86 |                     write!(f, "| Q ");
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:88:6
[INFO] [stdout]    |
[INFO] [stdout] 88 |                     write!(f, "|   ");
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:92:4
[INFO] [stdout]    |
[INFO] [stdout] 92 |             write!(f, "|\n");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:95:5
[INFO] [stdout]    |
[INFO] [stdout] 95 |                 write!(f, "+---");
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:97:4
[INFO] [stdout]    |
[INFO] [stdout] 97 |             write!(f, "+\n");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `startTime` should have a snake case name
[INFO] [stdout]    --> src/main.rs:220:7
[INFO] [stdout]     |
[INFO] [stdout] 220 |         let startTime = Stopwatch::start_new();
[INFO] [stdout]     |             ^^^^^^^^^ help: convert the identifier to snake case: `start_time`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 16 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 8.59s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: rustc-serialize v0.3.24
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 1`
[INFO] running `Command { std: "docker" "inspect" "0ebdccdfc852f21c58c31fcb00786ee41bc7dfe12a7f9727a4a34919e8582bee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0ebdccdfc852f21c58c31fcb00786ee41bc7dfe12a7f9727a4a34919e8582bee", kill_on_drop: false }`
[INFO] [stdout] 0ebdccdfc852f21c58c31fcb00786ee41bc7dfe12a7f9727a4a34919e8582bee
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 41ea480e342966543ef5c31f6aade6bf0f12f5ec71d8a5198c4338f6424671e1
[INFO] running `Command { std: "docker" "start" "-a" "41ea480e342966543ef5c31f6aade6bf0f12f5ec71d8a5198c4338f6424671e1", kill_on_drop: false }`
[INFO] [stderr]    Compiling nqueens-rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:118:12
[INFO] [stdout]     |
[INFO] [stdout] 118 |         for i in (0..=N) {
[INFO] [stdout]     |                  ^     ^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout] 118 -         for i in (0..=N) {
[INFO] [stdout] 118 +         for i in 0..=N {
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:119:13
[INFO] [stdout]     |
[INFO] [stdout] 119 |             for j in (0..=N) {
[INFO] [stdout]     |                      ^     ^
[INFO] [stdout]     |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout] 119 -             for j in (0..=N) {
[INFO] [stdout] 119 +             for j in 0..=N {
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:182:12
[INFO] [stdout]     |
[INFO] [stdout] 182 |         for i in (0..N) {
[INFO] [stdout]     |                  ^    ^
[INFO] [stdout]     |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout] 182 -         for i in (0..N) {
[INFO] [stdout] 182 +         for i in 0..N {
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:183:13
[INFO] [stdout]     |
[INFO] [stdout] 183 |             for j in (0..N) {
[INFO] [stdout]     |                      ^    ^
[INFO] [stdout]     |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout] 183 -             for j in (0..N) {
[INFO] [stdout] 183 +             for j in 0..N {
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]    --> src/main.rs:245:13
[INFO] [stdout]     |
[INFO] [stdout] 245 |     let time = (sw.elapsed_ms() as f64);
[INFO] [stdout]     |                ^                      ^
[INFO] [stdout]     |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout] 245 -     let time = (sw.elapsed_ms() as f64);
[INFO] [stdout] 245 +     let time = sw.elapsed_ms() as f64;
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]    --> src/main.rs:118:7
[INFO] [stdout]     |
[INFO] [stdout] 118 |         for i in (0..=N) {
[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: `children`
[INFO] [stdout]    --> src/main.rs:219:7
[INFO] [stdout]     |
[INFO] [stdout] 219 |         let children = self.children();
[INFO] [stdout]     |             ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_children`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `n_queens_bestfs` is never used
[INFO] [stdout]    --> src/main.rs:193:5
[INFO] [stdout]     |
[INFO] [stdout] 104 | impl Board {
[INFO] [stdout]     | ---------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 193 |     fn n_queens_bestfs(&self, n:i32) -> (Board, i32) {
[INFO] [stdout]     |        ^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:78:4
[INFO] [stdout]    |
[INFO] [stdout] 78 |             write!(f, "+---");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:81:3
[INFO] [stdout]    |
[INFO] [stdout] 81 |         write!(f, "+\n");
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:86:6
[INFO] [stdout]    |
[INFO] [stdout] 86 |                     write!(f, "| Q ");
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:88:6
[INFO] [stdout]    |
[INFO] [stdout] 88 |                     write!(f, "|   ");
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:92:4
[INFO] [stdout]    |
[INFO] [stdout] 92 |             write!(f, "|\n");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:95:5
[INFO] [stdout]    |
[INFO] [stdout] 95 |                 write!(f, "+---");
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:97:4
[INFO] [stdout]    |
[INFO] [stdout] 97 |             write!(f, "+\n");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `startTime` should have a snake case name
[INFO] [stdout]    --> src/main.rs:220:7
[INFO] [stdout]     |
[INFO] [stdout] 220 |         let startTime = Stopwatch::start_new();
[INFO] [stdout]     |             ^^^^^^^^^ help: convert the identifier to snake case: `start_time`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.43s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: rustc-serialize v0.3.24
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 1`
[INFO] [stdout] warning: 16 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "41ea480e342966543ef5c31f6aade6bf0f12f5ec71d8a5198c4338f6424671e1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "41ea480e342966543ef5c31f6aade6bf0f12f5ec71d8a5198c4338f6424671e1", kill_on_drop: false }`
[INFO] [stdout] 41ea480e342966543ef5c31f6aade6bf0f12f5ec71d8a5198c4338f6424671e1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 45928c1a1f41f0c6f8d333f8676bbe8276a48e1963e038bbcd094595f0e5315b
[INFO] running `Command { std: "docker" "start" "-a" "45928c1a1f41f0c6f8d333f8676bbe8276a48e1963e038bbcd094595f0e5315b", kill_on_drop: false }`
[INFO] [stderr] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stderr]    --> src/main.rs:118:12
[INFO] [stderr]     |
[INFO] [stderr] 118 |         for i in (0..=N) {
[INFO] [stderr]     |                  ^     ^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stderr] help: remove these parentheses
[INFO] [stderr]     |
[INFO] [stderr] 118 -         for i in (0..=N) {
[INFO] [stderr] 118 +         for i in 0..=N {
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stderr]    --> src/main.rs:119:13
[INFO] [stderr]     |
[INFO] [stderr] 119 |             for j in (0..=N) {
[INFO] [stderr]     |                      ^     ^
[INFO] [stderr]     |
[INFO] [stderr] help: remove these parentheses
[INFO] [stderr]     |
[INFO] [stderr] 119 -             for j in (0..=N) {
[INFO] [stderr] 119 +             for j in 0..=N {
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stderr]    --> src/main.rs:182:12
[INFO] [stderr]     |
[INFO] [stderr] 182 |         for i in (0..N) {
[INFO] [stderr]     |                  ^    ^
[INFO] [stderr]     |
[INFO] [stderr] help: remove these parentheses
[INFO] [stderr]     |
[INFO] [stderr] 182 -         for i in (0..N) {
[INFO] [stderr] 182 +         for i in 0..N {
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stderr]    --> src/main.rs:183:13
[INFO] [stderr]     |
[INFO] [stderr] 183 |             for j in (0..N) {
[INFO] [stderr]     |                      ^    ^
[INFO] [stderr]     |
[INFO] [stderr] help: remove these parentheses
[INFO] [stderr]     |
[INFO] [stderr] 183 -             for j in (0..N) {
[INFO] [stderr] 183 +             for j in 0..N {
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around assigned value
[INFO] [stderr]    --> src/main.rs:245:13
[INFO] [stderr]     |
[INFO] [stderr] 245 |     let time = (sw.elapsed_ms() as f64);
[INFO] [stderr]     |                ^                      ^
[INFO] [stderr]     |
[INFO] [stderr] help: remove these parentheses
[INFO] [stderr]     |
[INFO] [stderr] 245 -     let time = (sw.elapsed_ms() as f64);
[INFO] [stderr] 245 +     let time = sw.elapsed_ms() as f64;
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `i`
[INFO] [stderr]    --> src/main.rs:118:7
[INFO] [stderr]     |
[INFO] [stderr] 118 |         for i in (0..=N) {
[INFO] [stderr]     |             ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `children`
[INFO] [stderr]    --> src/main.rs:219:7
[INFO] [stderr]     |
[INFO] [stderr] 219 |         let children = self.children();
[INFO] [stderr]     |             ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_children`
[INFO] [stderr] 
[INFO] [stderr] warning: method `n_queens_bestfs` is never used
[INFO] [stderr]    --> src/main.rs:193:5
[INFO] [stderr]     |
[INFO] [stderr] 104 | impl Board {
[INFO] [stderr]     | ---------- method in this implementation
[INFO] [stderr] ...
[INFO] [stderr] 193 |     fn n_queens_bestfs(&self, n:i32) -> (Board, i32) {
[INFO] [stderr]     |        ^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/main.rs:78:4
[INFO] [stderr]    |
[INFO] [stderr] 78 |             write!(f, "+---");
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/main.rs:81:3
[INFO] [stderr]    |
[INFO] [stderr] 81 |         write!(f, "+\n");
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/main.rs:86:6
[INFO] [stderr]    |
[INFO] [stderr] 86 |                     write!(f, "| Q ");
[INFO] [stderr]    |                     ^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/main.rs:88:6
[INFO] [stderr]    |
[INFO] [stderr] 88 |                     write!(f, "|   ");
[INFO] [stderr]    |                     ^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/main.rs:92:4
[INFO] [stderr]    |
[INFO] [stderr] 92 |             write!(f, "|\n");
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/main.rs:95:5
[INFO] [stderr]    |
[INFO] [stderr] 95 |                 write!(f, "+---");
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/main.rs:97:4
[INFO] [stderr]    |
[INFO] [stderr] 97 |             write!(f, "+\n");
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: variable `startTime` should have a snake case name
[INFO] [stderr]    --> src/main.rs:220:7
[INFO] [stderr]     |
[INFO] [stderr] 220 |         let startTime = Stopwatch::start_new();
[INFO] [stderr]     |             ^^^^^^^^^ help: convert the identifier to snake case: `start_time`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(non_snake_case)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: `nqueens-rs` (bin "nqueens-rs" test) generated 16 warnings (run `cargo fix --bin "nqueens-rs" --tests` to apply 7 suggestions)
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: rustc-serialize v0.3.24
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 1`
[INFO] [stderr]      Running unittests src/main.rs (/opt/rustwide/target/debug/deps/nqueens_rs-8bae66b96dc696cf)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "45928c1a1f41f0c6f8d333f8676bbe8276a48e1963e038bbcd094595f0e5315b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "45928c1a1f41f0c6f8d333f8676bbe8276a48e1963e038bbcd094595f0e5315b", kill_on_drop: false }`
[INFO] [stdout] 45928c1a1f41f0c6f8d333f8676bbe8276a48e1963e038bbcd094595f0e5315b
