[INFO] updating cached repository srufle/maze-book-rs
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/srufle/maze-book-rs
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/srufle/maze-book-rs" "work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/gh/srufle/maze-book-rs"`
[INFO] [stderr] Cloning into 'work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/gh/srufle/maze-book-rs'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/srufle/maze-book-rs" "work/ex/pr-60914/sources/try#f45cc3094ee337acd688771b9234318046b0572d/gh/srufle/maze-book-rs"`
[INFO] [stderr] Cloning into 'work/ex/pr-60914/sources/try#f45cc3094ee337acd688771b9234318046b0572d/gh/srufle/maze-book-rs'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 7fced78106ff9f31c76a9dec2815bdbe6200d070
[INFO] sha for GitHub repo srufle/maze-book-rs: 7fced78106ff9f31c76a9dec2815bdbe6200d070
[INFO] validating manifest of srufle/maze-book-rs on toolchain master#39401465da4ce27aeeb2c2a26133ac35c63aa515
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+39401465da4ce27aeeb2c2a26133ac35c63aa515-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of srufle/maze-book-rs on toolchain try#f45cc3094ee337acd688771b9234318046b0572d
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+f45cc3094ee337acd688771b9234318046b0572d-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing srufle/maze-book-rs
[INFO] finished frobbing srufle/maze-book-rs
[INFO] frobbed toml for srufle/maze-book-rs written to work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/gh/srufle/maze-book-rs/Cargo.toml
[INFO] started frobbing srufle/maze-book-rs
[INFO] finished frobbing srufle/maze-book-rs
[INFO] frobbed toml for srufle/maze-book-rs written to work/ex/pr-60914/sources/try#f45cc3094ee337acd688771b9234318046b0572d/gh/srufle/maze-book-rs/Cargo.toml
[INFO] crate srufle/maze-book-rs already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+39401465da4ce27aeeb2c2a26133ac35c63aa515-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+f45cc3094ee337acd688771b9234318046b0572d-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking srufle/maze-book-rs against try#f45cc3094ee337acd688771b9234318046b0572d for pr-60914
[INFO] running `"docker" "create" "-v" "/mnt/crater-raid/crater/work/local/target-dirs/pr-60914/worker-4/try#f45cc3094ee337acd688771b9234318046b0572d:/opt/crater/target:rw,Z" "-v" "/mnt/crater-raid/crater/work/ex/pr-60914/sources/try#f45cc3094ee337acd688771b9234318046b0572d/gh/srufle/maze-book-rs:/opt/crater/workdir:ro,Z" "-v" "/mnt/crater-raid/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/crater-raid/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+f45cc3094ee337acd688771b9234318046b0572d-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] e8281b33bd5bb89a6a93a5293d8e2c3089211c224b87c3e662857e08dd4c45dc
[INFO] running `"docker" "start" "-a" "e8281b33bd5bb89a6a93a5293d8e2c3089211c224b87c3e662857e08dd4c45dc"`
[INFO] [stderr]    Compiling syn v0.15.31
[INFO] [stderr]    Compiling slog v2.4.1
[INFO] [stderr]     Checking dirs v1.0.5
[INFO] [stderr]     Checking isatty v0.1.9
[INFO] [stderr]     Checking rusttype v0.7.5
[INFO] [stderr]     Checking chrono v0.4.6
[INFO] [stderr]     Checking term v0.5.2
[INFO] [stderr]     Checking slog-async v2.3.0
[INFO] [stderr]     Checking slog-term v2.4.0
[INFO] [stderr]    Compiling num-derive v0.2.4
[INFO] [stderr]     Checking tiff v0.2.2
[INFO] [stderr]     Checking image v0.21.1
[INFO] [stderr]     Checking imageproc v0.18.0
[INFO] [stderr]     Checking maze-book-rs v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `maze::Grid`
[INFO] [stderr]  --> src/main.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use maze::Grid;
[INFO] [stderr]   |     ^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `maze::Maze`
[INFO] [stderr]  --> src/main.rs:6:5
[INFO] [stderr]   |
[INFO] [stderr] 6 | use maze::Maze;
[INFO] [stderr]   |     ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: value assigned to `output` is never read
[INFO] [stderr]   --> src/maze/grid.rs:59:17
[INFO] [stderr]    |
[INFO] [stderr] 59 |         let mut output = "".to_string();
[INFO] [stderr]    |                 ^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_assignments)] on by default
[INFO] [stderr]    = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: value assigned to `output` is never read
[INFO] [stderr]   --> src/maze/grid.rs:59:17
[INFO] [stderr]    |
[INFO] [stderr] 59 |         let mut output = "".to_string();
[INFO] [stderr]    |                 ^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_assignments)] on by default
[INFO] [stderr]    = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/maze/grid.rs:120:13
[INFO] [stderr]     |
[INFO] [stderr] 120 |         let mut cells = self.cells();
[INFO] [stderr]     |             ----^^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `generate_fixed_grid`
[INFO] [stderr]   --> src/maze/binary_tree.rs:49:1
[INFO] [stderr]    |
[INFO] [stderr] 49 | pub fn generate_fixed_grid(maze: &mut Grid) {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `South`
[INFO] [stderr]   --> src/maze/direction.rs:10:5
[INFO] [stderr]    |
[INFO] [stderr] 10 |     South,
[INFO] [stderr]    |     ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `West`
[INFO] [stderr]   --> src/maze/direction.rs:11:5
[INFO] [stderr]    |
[INFO] [stderr] 11 |     West,
[INFO] [stderr]    |     ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never used: `visited`
[INFO] [stderr]   --> src/maze/grid.rs:21:5
[INFO] [stderr]    |
[INFO] [stderr] 21 |     visited: HashSet<(usize, usize)>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_lower`
[INFO] [stderr]    --> src/maze/grid.rs:272:5
[INFO] [stderr]     |
[INFO] [stderr] 272 |     pub fn at_lower(&self, row: usize) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_left`
[INFO] [stderr]    --> src/maze/grid.rs:280:5
[INFO] [stderr]     |
[INFO] [stderr] 280 |     pub fn at_left(&self, col: usize) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_upper_left`
[INFO] [stderr]    --> src/maze/grid.rs:284:5
[INFO] [stderr]     |
[INFO] [stderr] 284 |     pub fn at_upper_left(&self, col: usize, row: usize) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_lower_left`
[INFO] [stderr]    --> src/maze/grid.rs:292:5
[INFO] [stderr]     |
[INFO] [stderr] 292 |     pub fn at_lower_left(&self, col: usize, row: usize) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_lower_right`
[INFO] [stderr]    --> src/maze/grid.rs:296:5
[INFO] [stderr]     |
[INFO] [stderr] 296 |     pub fn at_lower_right(&self, col: usize, row: usize) -> bool {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_lower`
[INFO] [stderr]   --> src/maze/maze.rs:53:5
[INFO] [stderr]    |
[INFO] [stderr] 53 |     pub fn at_lower(&self, row: usize) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_left`
[INFO] [stderr]   --> src/maze/maze.rs:61:5
[INFO] [stderr]    |
[INFO] [stderr] 61 |     pub fn at_left(&self, col: usize) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_upper_left`
[INFO] [stderr]   --> src/maze/maze.rs:65:5
[INFO] [stderr]    |
[INFO] [stderr] 65 |     pub fn at_upper_left(&self, col: usize, row: usize) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_lower_left`
[INFO] [stderr]   --> src/maze/maze.rs:73:5
[INFO] [stderr]    |
[INFO] [stderr] 73 |     pub fn at_lower_left(&self, col: usize, row: usize) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_lower_right`
[INFO] [stderr]   --> src/maze/maze.rs:77:5
[INFO] [stderr]    |
[INFO] [stderr] 77 |     pub fn at_lower_right(&self, col: usize, row: usize) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `direction`
[INFO] [stderr]   --> src/maze/position.rs:42:5
[INFO] [stderr]    |
[INFO] [stderr] 42 |     pub fn direction(&self) -> Direction {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/maze/grid.rs:120:13
[INFO] [stderr]     |
[INFO] [stderr] 120 |         let mut cells = self.cells();
[INFO] [stderr]     |             ----^^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `generate`
[INFO] [stderr]  --> src/maze/binary_tree.rs:7:1
[INFO] [stderr]   |
[INFO] [stderr] 7 | pub fn generate(maze: &Maze) {
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `generate_grid`
[INFO] [stderr]   --> src/maze/binary_tree.rs:28:1
[INFO] [stderr]    |
[INFO] [stderr] 28 | pub fn generate_grid(maze: &mut Grid) {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `generate_fixed_grid`
[INFO] [stderr]   --> src/maze/binary_tree.rs:49:1
[INFO] [stderr]    |
[INFO] [stderr] 49 | pub fn generate_fixed_grid(maze: &mut Grid) {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `row`
[INFO] [stderr]   --> src/maze/cell.rs:43:5
[INFO] [stderr]    |
[INFO] [stderr] 43 |     pub fn row(&self) -> usize {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `col`
[INFO] [stderr]   --> src/maze/cell.rs:46:5
[INFO] [stderr]    |
[INFO] [stderr] 46 |     pub fn col(&self) -> usize {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `None`
[INFO] [stderr]  --> src/maze/direction.rs:7:5
[INFO] [stderr]   |
[INFO] [stderr] 7 |     None,
[INFO] [stderr]   |     ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `North`
[INFO] [stderr]  --> src/maze/direction.rs:8:5
[INFO] [stderr]   |
[INFO] [stderr] 8 |     North,
[INFO] [stderr]   |     ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `East`
[INFO] [stderr]  --> src/maze/direction.rs:9:5
[INFO] [stderr]   |
[INFO] [stderr] 9 |     East,
[INFO] [stderr]   |     ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `South`
[INFO] [stderr]   --> src/maze/direction.rs:10:5
[INFO] [stderr]    |
[INFO] [stderr] 10 |     South,
[INFO] [stderr]    |     ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `West`
[INFO] [stderr]   --> src/maze/direction.rs:11:5
[INFO] [stderr]    |
[INFO] [stderr] 11 |     West,
[INFO] [stderr]    |     ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never used: `visited`
[INFO] [stderr]   --> src/maze/grid.rs:21:5
[INFO] [stderr]    |
[INFO] [stderr] 21 |     visited: HashSet<(usize, usize)>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `display`
[INFO] [stderr]   --> src/maze/grid.rs:43:5
[INFO] [stderr]    |
[INFO] [stderr] 43 |     pub fn display(&self) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `render_ascii`
[INFO] [stderr]   --> src/maze/grid.rs:58:5
[INFO] [stderr]    |
[INFO] [stderr] 58 |     pub fn render_ascii(&self) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `render_png`
[INFO] [stderr]   --> src/maze/grid.rs:96:5
[INFO] [stderr]    |
[INFO] [stderr] 96 |     pub fn render_png(&self, name: &String) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `cells`
[INFO] [stderr]    --> src/maze/grid.rs:238:5
[INFO] [stderr]     |
[INFO] [stderr] 238 |     pub fn cells(&self) -> Cells {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `logger`
[INFO] [stderr]    --> src/maze/grid.rs:308:5
[INFO] [stderr]     |
[INFO] [stderr] 308 |     fn logger() -> Logger {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Maze`
[INFO] [stderr]   --> src/maze/maze.rs:12:1
[INFO] [stderr]    |
[INFO] [stderr] 12 | pub struct Maze {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/maze/maze.rs:19:5
[INFO] [stderr]    |
[INFO] [stderr] 19 |     pub fn new(width: usize, length: usize) -> Maze {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `blank`
[INFO] [stderr]   --> src/maze/maze.rs:27:5
[INFO] [stderr]    |
[INFO] [stderr] 27 |     pub fn blank(width: usize, length: usize) -> Maze {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `logger`
[INFO] [stderr]   --> src/maze/maze.rs:36:5
[INFO] [stderr]    |
[INFO] [stderr] 36 |     fn logger() -> Logger {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `total_cells`
[INFO] [stderr]   --> src/maze/maze.rs:45:5
[INFO] [stderr]    |
[INFO] [stderr] 45 |     pub fn total_cells(&self) -> usize {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_upper`
[INFO] [stderr]   --> src/maze/maze.rs:49:5
[INFO] [stderr]    |
[INFO] [stderr] 49 |     pub fn at_upper(&self, row: usize) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_lower`
[INFO] [stderr]   --> src/maze/maze.rs:53:5
[INFO] [stderr]    |
[INFO] [stderr] 53 |     pub fn at_lower(&self, row: usize) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_right`
[INFO] [stderr]   --> src/maze/maze.rs:57:5
[INFO] [stderr]    |
[INFO] [stderr] 57 |     pub fn at_right(&self, col: usize) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_left`
[INFO] [stderr]   --> src/maze/maze.rs:61:5
[INFO] [stderr]    |
[INFO] [stderr] 61 |     pub fn at_left(&self, col: usize) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_upper_left`
[INFO] [stderr]   --> src/maze/maze.rs:65:5
[INFO] [stderr]    |
[INFO] [stderr] 65 |     pub fn at_upper_left(&self, col: usize, row: usize) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_upper_right`
[INFO] [stderr]   --> src/maze/maze.rs:69:5
[INFO] [stderr]    |
[INFO] [stderr] 69 |     pub fn at_upper_right(&self, col: usize, row: usize) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_lower_left`
[INFO] [stderr]   --> src/maze/maze.rs:73:5
[INFO] [stderr]    |
[INFO] [stderr] 73 |     pub fn at_lower_left(&self, col: usize, row: usize) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `at_lower_right`
[INFO] [stderr]   --> src/maze/maze.rs:77:5
[INFO] [stderr]    |
[INFO] [stderr] 77 |     pub fn at_lower_right(&self, col: usize, row: usize) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `width`
[INFO] [stderr]   --> src/maze/maze.rs:81:5
[INFO] [stderr]    |
[INFO] [stderr] 81 |     pub fn width(&self) -> usize {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `length`
[INFO] [stderr]   --> src/maze/maze.rs:85:5
[INFO] [stderr]    |
[INFO] [stderr] 85 |     pub fn length(&self) -> usize {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `display`
[INFO] [stderr]   --> src/maze/maze.rs:89:5
[INFO] [stderr]    |
[INFO] [stderr] 89 |     pub fn display(&self) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `push_position`
[INFO] [stderr]    --> src/maze/maze.rs:104:5
[INFO] [stderr]     |
[INFO] [stderr] 104 |     pub fn push_position(&self, position: Position) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `positions`
[INFO] [stderr]    --> src/maze/maze.rs:108:5
[INFO] [stderr]     |
[INFO] [stderr] 108 |     pub fn positions(&self) -> Vec<Position> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: type alias is never used: `Positions`
[INFO] [stderr]  --> src/maze/position.rs:6:1
[INFO] [stderr]   |
[INFO] [stderr] 6 | pub type Positions = RefCell<Vec<Position>>;
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/maze/position.rs:16:5
[INFO] [stderr]    |
[INFO] [stderr] 16 |     pub fn new(col: usize, row: usize, directions: Direction) -> Position {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `col`
[INFO] [stderr]   --> src/maze/position.rs:25:5
[INFO] [stderr]    |
[INFO] [stderr] 25 |     pub fn col(&self) -> usize {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `row`
[INFO] [stderr]   --> src/maze/position.rs:28:5
[INFO] [stderr]    |
[INFO] [stderr] 28 |     pub fn row(&self) -> usize {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `push_direction`
[INFO] [stderr]   --> src/maze/position.rs:31:5
[INFO] [stderr]    |
[INFO] [stderr] 31 |     pub fn push_direction(&self, direction: Direction) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `pop_direction`
[INFO] [stderr]   --> src/maze/position.rs:35:5
[INFO] [stderr]    |
[INFO] [stderr] 35 |     pub fn pop_direction(&self) -> Option<Direction> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `direction`
[INFO] [stderr]   --> src/maze/position.rs:42:5
[INFO] [stderr]    |
[INFO] [stderr] 42 |     pub fn direction(&self) -> Direction {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `generate`
[INFO] [stderr]  --> src/maze/sidewinder.rs:7:1
[INFO] [stderr]   |
[INFO] [stderr] 7 | pub fn generate(maze: &Maze) {
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `copy_run`
[INFO] [stderr]   --> src/maze/sidewinder.rs:42:1
[INFO] [stderr]    |
[INFO] [stderr] 42 | pub fn copy_run(maze: &Maze, run: &Vec<Position>) {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `generate_grid`
[INFO] [stderr]   --> src/maze/sidewinder.rs:59:1
[INFO] [stderr]    |
[INFO] [stderr] 59 | pub fn generate_grid(maze: &mut Grid) {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `coin_flip`
[INFO] [stderr]  --> src/maze/utils.rs:5:1
[INFO] [stderr]   |
[INFO] [stderr] 5 | pub fn coin_flip() -> bool {
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `choose_cell`
[INFO] [stderr]   --> src/maze/utils.rs:10:1
[INFO] [stderr]    |
[INFO] [stderr] 10 | pub fn choose_cell(low: usize, high: usize) -> usize {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 22.33s
[INFO] running `"docker" "inspect" "e8281b33bd5bb89a6a93a5293d8e2c3089211c224b87c3e662857e08dd4c45dc"`
[INFO] running `"docker" "rm" "-f" "e8281b33bd5bb89a6a93a5293d8e2c3089211c224b87c3e662857e08dd4c45dc"`
[INFO] [stdout] e8281b33bd5bb89a6a93a5293d8e2c3089211c224b87c3e662857e08dd4c45dc