[INFO] cloning repository https://github.com/EkardNT/sudoku
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/EkardNT/sudoku" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FEkardNT%2Fsudoku", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FEkardNT%2Fsudoku'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3d13dad9d3a68019eab7c5cce1291d514f6f6e5e
[INFO] checking EkardNT/sudoku against master#cfbc6d4cf1acbac5c025acf8ed68929caa551df3 for pr-75494-beta
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FEkardNT%2Fsudoku" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/EkardNT/sudoku on toolchain cfbc6d4cf1acbac5c025acf8ed68929caa551df3
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cfbc6d4cf1acbac5c025acf8ed68929caa551df3" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/EkardNT/sudoku
[INFO] finished tweaking git repo https://github.com/EkardNT/sudoku
[INFO] tweaked toml for git repo https://github.com/EkardNT/sudoku written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/EkardNT/sudoku already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cfbc6d4cf1acbac5c025acf8ed68929caa551df3" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+cfbc6d4cf1acbac5c025acf8ed68929caa551df3" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3ec49b6f732e9859160c722e6aa070f78dae0791614076ea3fe49ca0a29f8d2c
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "3ec49b6f732e9859160c722e6aa070f78dae0791614076ea3fe49ca0a29f8d2c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3ec49b6f732e9859160c722e6aa070f78dae0791614076ea3fe49ca0a29f8d2c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3ec49b6f732e9859160c722e6aa070f78dae0791614076ea3fe49ca0a29f8d2c", kill_on_drop: false }`
[INFO] [stdout] 3ec49b6f732e9859160c722e6aa070f78dae0791614076ea3fe49ca0a29f8d2c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+cfbc6d4cf1acbac5c025acf8ed68929caa551df3" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 49f0dd7fdc1d621cc164528244fe9cfdc9f5d472870ee4592ff11e3afecb153e
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "49f0dd7fdc1d621cc164528244fe9cfdc9f5d472870ee4592ff11e3afecb153e", kill_on_drop: false }`
[INFO] [stderr]     Checking sudoku v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:185:15
[INFO] [stdout]     |
[INFO] [stdout] 185 |         while (current_down_index != header_index) {
[INFO] [stdout]     |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:191:19
[INFO] [stdout]     |
[INFO] [stdout] 191 |             while (current_right_index != current_down_index) {
[INFO] [stdout]     |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:223:15
[INFO] [stdout]     |
[INFO] [stdout] 223 |         while (current_up_index != header_index) {
[INFO] [stdout]     |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:229:19
[INFO] [stdout]     |
[INFO] [stdout] 229 |             while (current_left_index != current_up_index) {
[INFO] [stdout]     |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:307:15
[INFO] [stdout]     |
[INFO] [stdout] 307 |         while (current_down_index != min_header_index) {
[INFO] [stdout]     |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:313:19
[INFO] [stdout]     |
[INFO] [stdout] 313 |             while (current_right_index != current_down_index) {
[INFO] [stdout]     |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:332:19
[INFO] [stdout]     |
[INFO] [stdout] 332 |             while (current_left_index != current_down_index) {
[INFO] [stdout]     |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:358:15
[INFO] [stdout]     |
[INFO] [stdout] 358 |         while (current_header_index != Matrix::ROOT_INDEX) {
[INFO] [stdout]     |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]    --> src/matrix.rs:376:24
[INFO] [stdout]     |
[INFO] [stdout] 376 |                     if (current_index == row_front_index) {
[INFO] [stdout]     |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `NodeKind`, `Node`
[INFO] [stdout]    --> src/matrix.rs:389:25
[INFO] [stdout]     |
[INFO] [stdout] 389 |     use super::{Matrix, Node, NodeKind};
[INFO] [stdout]     |                         ^^^^  ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Display`, `Formatter`, `Write`
[INFO] [stdout]  --> src/lib.rs:5:16
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::fmt::{Display, Write, Formatter, Debug};
[INFO] [stdout]   |                ^^^^^^^  ^^^^^  ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::str::FromStr`
[INFO] [stdout]  --> src/lib.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::str::FromStr;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `matrix::*`
[INFO] [stdout]  --> src/lib.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use matrix::*;
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:185:15
[INFO] [stdout]     |
[INFO] [stdout] 185 |         while (current_down_index != header_index) {
[INFO] [stdout]     |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:191:19
[INFO] [stdout]     |
[INFO] [stdout] 191 |             while (current_right_index != current_down_index) {
[INFO] [stdout]     |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:223:15
[INFO] [stdout]     |
[INFO] [stdout] 223 |         while (current_up_index != header_index) {
[INFO] [stdout]     |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:229:19
[INFO] [stdout]     |
[INFO] [stdout] 229 |             while (current_left_index != current_up_index) {
[INFO] [stdout]     |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:307:15
[INFO] [stdout]     |
[INFO] [stdout] 307 |         while (current_down_index != min_header_index) {
[INFO] [stdout]     |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:313:19
[INFO] [stdout]     |
[INFO] [stdout] 313 |             while (current_right_index != current_down_index) {
[INFO] [stdout]     |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:332:19
[INFO] [stdout]     |
[INFO] [stdout] 332 |             while (current_left_index != current_down_index) {
[INFO] [stdout]     |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `while` condition
[INFO] [stdout]    --> src/matrix.rs:358:15
[INFO] [stdout]     |
[INFO] [stdout] 358 |         while (current_header_index != Matrix::ROOT_INDEX) {
[INFO] [stdout]     |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]    --> src/matrix.rs:376:24
[INFO] [stdout]     |
[INFO] [stdout] 376 |                     if (current_index == row_front_index) {
[INFO] [stdout]     |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Display`, `Formatter`, `Write`
[INFO] [stdout]  --> src/lib.rs:5:16
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::fmt::{Display, Write, Formatter, Debug};
[INFO] [stdout]   |                ^^^^^^^  ^^^^^  ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::str::FromStr`
[INFO] [stdout]  --> src/lib.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::str::FromStr;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `matrix::*`
[INFO] [stdout]  --> src/lib.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use matrix::*;
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sparse_row`
[INFO] [stdout]   --> src/lib.rs:95:17
[INFO] [stdout]    |
[INFO] [stdout] 95 |             let sparse_row = SparseRow::new(row_index);
[INFO] [stdout]    |                 ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_sparse_row`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `board`
[INFO] [stdout]    --> src/lib.rs:123:25
[INFO] [stdout]     |
[INFO] [stdout] 123 |     fn solve(&mut self, board: &mut Board) -> Result<(), ()> {
[INFO] [stdout]     |                         ^^^^^ help: if this is intentional, prefix it with an underscore: `_board`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `column`
[INFO] [stdout]    --> src/coords.rs:119:28
[INFO] [stdout]     |
[INFO] [stdout] 119 |     pub fn to_dense(&self, column: &SparseColumn) -> DenseRow {
[INFO] [stdout]     |                            ^^^^^^ help: if this is intentional, prefix it with an underscore: `_column`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]    --> src/board.rs:211:13
[INFO] [stdout]     |
[INFO] [stdout] 211 |         let i = col + row * 9;
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lib.rs:65:13
[INFO] [stdout]    |
[INFO] [stdout] 65 |         let mut matrix = [[Link::default(); NONZERO_CONSTRAINTS_PER_POSSIBILITY]; POSSIBILITIES];
[INFO] [stdout]    |             ----^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sparse_row`
[INFO] [stdout]   --> src/lib.rs:95:17
[INFO] [stdout]    |
[INFO] [stdout] 95 |             let sparse_row = SparseRow::new(row_index);
[INFO] [stdout]    |                 ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_sparse_row`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lib.rs:66:13
[INFO] [stdout]    |
[INFO] [stdout] 66 |         let mut headers = [Header::default(); CONSTRAINTS];
[INFO] [stdout]    |             ----^^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `board`
[INFO] [stdout]    --> src/lib.rs:123:25
[INFO] [stdout]     |
[INFO] [stdout] 123 |     fn solve(&mut self, board: &mut Board) -> Result<(), ()> {
[INFO] [stdout]     |                         ^^^^^ help: if this is intentional, prefix it with an underscore: `_board`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `column`
[INFO] [stdout]    --> src/coords.rs:119:28
[INFO] [stdout]     |
[INFO] [stdout] 119 |     pub fn to_dense(&self, column: &SparseColumn) -> DenseRow {
[INFO] [stdout]     |                            ^^^^^^ help: if this is intentional, prefix it with an underscore: `_column`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `dense_row_index`
[INFO] [stdout]    --> src/coords.rs:276:17
[INFO] [stdout]     |
[INFO] [stdout] 276 |             for dense_row_index in 0..9*9*9 {
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_dense_row_index`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lib.rs:92:17
[INFO] [stdout]    |
[INFO] [stdout] 92 |             let mut row: &mut [Link] = &mut self.matrix[row_index];
[INFO] [stdout]    |                 ----^^^
[INFO] [stdout]    |                 |
[INFO] [stdout]    |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]    --> src/board.rs:211:13
[INFO] [stdout]     |
[INFO] [stdout] 211 |         let i = col + row * 9;
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lib.rs:65:13
[INFO] [stdout]    |
[INFO] [stdout] 65 |         let mut matrix = [[Link::default(); NONZERO_CONSTRAINTS_PER_POSSIBILITY]; POSSIBILITIES];
[INFO] [stdout]    |             ----^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lib.rs:66:13
[INFO] [stdout]    |
[INFO] [stdout] 66 |         let mut headers = [Header::default(); CONSTRAINTS];
[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/lib.rs:92:17
[INFO] [stdout]    |
[INFO] [stdout] 92 |             let mut row: &mut [Link] = &mut self.matrix[row_index];
[INFO] [stdout]    |                 ----^^^
[INFO] [stdout]    |                 |
[INFO] [stdout]    |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `to_sparse`
[INFO] [stdout]   --> src/coords.rs:18:12
[INFO] [stdout]    |
[INFO] [stdout] 18 |     pub fn to_sparse(&self) -> SparseRow {
[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: `to_sparse`
[INFO] [stdout]    --> src/coords.rs:130:12
[INFO] [stdout]     |
[INFO] [stdout] 130 |     pub fn to_sparse(&self, row: &DenseRow) -> SparseColumn {
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant is never used: `POSSIBILITIES`
[INFO] [stdout]  --> src/matrix.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | const POSSIBILITIES: usize = 9 * 9 * 9;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant is never used: `CONSTRAINTS`
[INFO] [stdout]  --> src/matrix.rs:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | const CONSTRAINTS: usize = 9 * 9 + 9 * 9 + 9 * 9 + 9 * 9;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant is never used: `NONZERO_CONSTRAINTS_PER_POSSIBILITY`
[INFO] [stdout]   --> src/matrix.rs:13:1
[INFO] [stdout]    |
[INFO] [stdout] 13 | const NONZERO_CONSTRAINTS_PER_POSSIBILITY: usize = 4;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant is never used: `MATRIX_NODE_COUNT`
[INFO] [stdout]   --> src/matrix.rs:16:1
[INFO] [stdout]    |
[INFO] [stdout] 16 | const MATRIX_NODE_COUNT: usize = 1 + CONSTRAINTS + POSSIBILITIES * NONZERO_CONSTRAINTS_PER_POSSIBILITY;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]    --> src/matrix.rs:359:13
[INFO] [stdout]     |
[INFO] [stdout] 359 |             writeln!(f, "col {:?}", self.nodes[current_header_index]);
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]     = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/board.rs:84:13
[INFO] [stdout]    |
[INFO] [stdout] 84 |             write!(to, "{} ", c);
[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 a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/board.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |         write!(to, "{}", self.entries[9*9-1]);
[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 a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: comparison is useless due to type limits
[INFO] [stdout]    --> src/board.rs:158:25
[INFO] [stdout]     |
[INFO] [stdout] 158 |                 assert!(value >= 0 && value <= 9);
[INFO] [stdout]     |                         ^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_comparisons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]    --> src/board.rs:202:13
[INFO] [stdout]     |
[INFO] [stdout] 202 |             fmt_row(self, f, &mut buf, row);
[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: 30 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `to_sparse`
[INFO] [stdout]   --> src/coords.rs:18:12
[INFO] [stdout]    |
[INFO] [stdout] 18 |     pub fn to_sparse(&self) -> SparseRow {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant is never used: `POSSIBILITIES`
[INFO] [stdout]  --> src/matrix.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | const POSSIBILITIES: usize = 9 * 9 * 9;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant is never used: `CONSTRAINTS`
[INFO] [stdout]  --> src/matrix.rs:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | const CONSTRAINTS: usize = 9 * 9 + 9 * 9 + 9 * 9 + 9 * 9;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant is never used: `NONZERO_CONSTRAINTS_PER_POSSIBILITY`
[INFO] [stdout]   --> src/matrix.rs:13:1
[INFO] [stdout]    |
[INFO] [stdout] 13 | const NONZERO_CONSTRAINTS_PER_POSSIBILITY: usize = 4;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/bin/sudoku.rs:15:12
[INFO] [stdout]    |
[INFO] [stdout] 15 |         if (bytes_read == 0) {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant is never used: `MATRIX_NODE_COUNT`
[INFO] [stdout]   --> src/matrix.rs:16:1
[INFO] [stdout]    |
[INFO] [stdout] 16 | const MATRIX_NODE_COUNT: usize = 1 + CONSTRAINTS + POSSIBILITIES * NONZERO_CONSTRAINTS_PER_POSSIBILITY;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/bin/sudoku.rs:15:12
[INFO] [stdout]    |
[INFO] [stdout] 15 |         if (bytes_read == 0) {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]    --> src/matrix.rs:359:13
[INFO] [stdout]     |
[INFO] [stdout] 359 |             writeln!(f, "col {:?}", self.nodes[current_header_index]);
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]     = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/board.rs:84:13
[INFO] [stdout]    |
[INFO] [stdout] 84 |             write!(to, "{} ", c);
[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 a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/board.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |         write!(to, "{}", self.entries[9*9-1]);
[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 a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: comparison is useless due to type limits
[INFO] [stdout]    --> src/board.rs:158:25
[INFO] [stdout]     |
[INFO] [stdout] 158 |                 assert!(value >= 0 && value <= 9);
[INFO] [stdout]     |                         ^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_comparisons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]    --> src/board.rs:202:13
[INFO] [stdout]     |
[INFO] [stdout] 202 |             fmt_row(self, f, &mut buf, row);
[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: 31 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `core::str::<impl str>::trim` that must be used
[INFO] [stdout]   --> src/bin/sudoku.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |         line.trim();
[INFO] [stdout]    |         ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this returns the trimmed string as a slice, without modifying the original
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/bin/sudoku.rs:29:13
[INFO] [stdout]    |
[INFO] [stdout] 29 |             writeln!(stdout_lock);
[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 a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/bin/sudoku.rs:30:13
[INFO] [stdout]    |
[INFO] [stdout] 30 |             stdout_lock.flush();
[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: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `core::str::<impl str>::trim` that must be used
[INFO] [stdout]   --> src/bin/sudoku.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |         line.trim();
[INFO] [stdout]    |         ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this returns the trimmed string as a slice, without modifying the original
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/bin/sudoku.rs:29:13
[INFO] [stdout]    |
[INFO] [stdout] 29 |             writeln!(stdout_lock);
[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 a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/bin/sudoku.rs:30:13
[INFO] [stdout]    |
[INFO] [stdout] 30 |             stdout_lock.flush();
[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: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.98s
[INFO] running `Command { std: "docker" "inspect" "49f0dd7fdc1d621cc164528244fe9cfdc9f5d472870ee4592ff11e3afecb153e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "49f0dd7fdc1d621cc164528244fe9cfdc9f5d472870ee4592ff11e3afecb153e", kill_on_drop: false }`
[INFO] [stdout] 49f0dd7fdc1d621cc164528244fe9cfdc9f5d472870ee4592ff11e3afecb153e
