[INFO] cloning repository https://github.com/joshuacox1/exact-cover
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/joshuacox1/exact-cover" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjoshuacox1%2Fexact-cover", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjoshuacox1%2Fexact-cover'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0f435891e004c4cf6aba04ac7353e45601b68545
[INFO] testing joshuacox1/exact-cover against master#0d162b25edd5bf0dba9a22e83b614f1113e90474 for pr-150681
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjoshuacox1%2Fexact-cover" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/joshuacox1/exact-cover
[INFO] finished tweaking git repo https://github.com/joshuacox1/exact-cover
[INFO] tweaked toml for git repo https://github.com/joshuacox1/exact-cover written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/joshuacox1/exact-cover on toolchain 0d162b25edd5bf0dba9a22e83b614f1113e90474
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+0d162b25edd5bf0dba9a22e83b614f1113e90474" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/joshuacox1/exact-cover 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" "+0d162b25edd5bf0dba9a22e83b614f1113e90474" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:845e597a41426bbf2703be69acdb67d10b6de511142d05cba7bbe119c898b2c7" "/opt/rustwide/cargo-home/bin/cargo" "+0d162b25edd5bf0dba9a22e83b614f1113e90474" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6b43f2ca26559e6760461cb740cb4ddee821f1d8950d66958835e340faf2e73b
[INFO] running `Command { std: "docker" "start" "-a" "6b43f2ca26559e6760461cb740cb4ddee821f1d8950d66958835e340faf2e73b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6b43f2ca26559e6760461cb740cb4ddee821f1d8950d66958835e340faf2e73b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6b43f2ca26559e6760461cb740cb4ddee821f1d8950d66958835e340faf2e73b", kill_on_drop: false }`
[INFO] [stdout] 6b43f2ca26559e6760461cb740cb4ddee821f1d8950d66958835e340faf2e73b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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=forbid" "-e" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:845e597a41426bbf2703be69acdb67d10b6de511142d05cba7bbe119c898b2c7" "/opt/rustwide/cargo-home/bin/cargo" "+0d162b25edd5bf0dba9a22e83b614f1113e90474" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1ddbc96a6b99c9c8f282413e24b3e096b7daa5722a65ad73ece82b4694088915
[INFO] running `Command { std: "docker" "start" "-a" "1ddbc96a6b99c9c8f282413e24b3e096b7daa5722a65ad73ece82b4694088915", kill_on_drop: false }`
[INFO] [stderr]    Compiling either v1.15.0
[INFO] [stderr]    Compiling bumpalo v3.19.0
[INFO] [stderr]    Compiling itertools v0.14.0
[INFO] [stderr]    Compiling exact_cover_solver v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `ExactCoverSolver`
[INFO] [stdout]  --> src/solver/representable.rs:2:17
[INFO] [stdout]   |
[INFO] [stdout] 2 |     ExactCover, ExactCoverSolver, ExactCoverProblem, PartialCover
[INFO] [stdout]   |                 ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `arrayvec::ArrayVec`
[INFO] [stdout]  --> src/solver/solver.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use arrayvec::ArrayVec;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `itertools::Itertools`
[INFO] [stdout]  --> src/solver/solver.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use itertools::Itertools;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type `ENTRY_IDX` should have an upper camel case name
[INFO] [stdout]   --> src/solver/solver.rs:83:6
[INFO] [stdout]    |
[INFO] [stdout] 83 | type ENTRY_IDX = u16;
[INFO] [stdout]    |      ^^^^^^^^^ help: convert the identifier to upper camel case: `EntryIdx`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_camel_case_types)]` (part of `#[warn(nonstandard_style)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type `COL_OR_ROW_IDX` should have an upper camel case name
[INFO] [stdout]   --> src/solver/solver.rs:84:6
[INFO] [stdout]    |
[INFO] [stdout] 84 | type COL_OR_ROW_IDX = u16;
[INFO] [stdout]    |      ^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `ColOrRowIdx`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `ExactCoverProblemError` and `SparseBinaryMatrix`
[INFO] [stdout]   --> src/solver/mod.rs:12:38
[INFO] [stdout]    |
[INFO] [stdout] 12 | pub use problem::{ExactCoverProblem, ExactCoverProblemError,
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 13 | SparseBinaryMatrix};
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `ExactCoverSolver`
[INFO] [stdout]  --> src/problems/n_queens.rs:7:21
[INFO] [stdout]   |
[INFO] [stdout] 7 |         ExactCover, ExactCoverSolver, ExactCoverProblem, PartialCover,
[INFO] [stdout]   |                     ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `o_rows` and `empty_rows` are never read
[INFO] [stdout]   --> src/solver/solver.rs:59:5
[INFO] [stdout]    |
[INFO] [stdout] 54 | pub struct ExactCoverSolver {
[INFO] [stdout]    |            ---------------- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 59 |     o_rows: Vec<usize>,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 64 |     empty_rows: Vec<usize>,
[INFO] [stdout]    |     ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `ExactCoverSolver` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `MAX_COLS` is never used
[INFO] [stdout]   --> src/solver/solver.rs:73:7
[INFO] [stdout]    |
[INFO] [stdout] 73 | const MAX_COLS: usize = 4096;
[INFO] [stdout]    |       ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `MAX_ROWS` is never used
[INFO] [stdout]   --> src/solver/solver.rs:74:7
[INFO] [stdout]    |
[INFO] [stdout] 74 | const MAX_ROWS: usize = 4096;
[INFO] [stdout]    |       ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `MAX_ONES` is never used
[INFO] [stdout]   --> src/solver/solver.rs:75:7
[INFO] [stdout]    |
[INFO] [stdout] 75 | const MAX_ONES: usize = 65536 - MAX_COLS;
[INFO] [stdout]    |       ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `ENTRY_IDX` is never used
[INFO] [stdout]   --> src/solver/solver.rs:83:6
[INFO] [stdout]    |
[INFO] [stdout] 83 | type ENTRY_IDX = u16;
[INFO] [stdout]    |      ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `COL_OR_ROW_IDX` is never used
[INFO] [stdout]   --> src/solver/solver.rs:84:6
[INFO] [stdout]    |
[INFO] [stdout] 84 | type COL_OR_ROW_IDX = u16;
[INFO] [stdout]    |      ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/solver/solver.rs:346:27
[INFO] [stdout]     |
[INFO] [stdout] 346 |     pub fn iter_solutions(&mut self) -> Solutions {
[INFO] [stdout]     |                           ^^^^^^^^^     ^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                           |
[INFO] [stdout]     |                           the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]     = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 346 |     pub fn iter_solutions(&mut self) -> Solutions<'_> {
[INFO] [stdout]     |                                                  ++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/solver/solver.rs:351:23
[INFO] [stdout]     |
[INFO] [stdout] 351 |     pub fn iter_steps(&mut self) -> SolverSteps {
[INFO] [stdout]     |                       ^^^^^^^^^     ^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                       |
[INFO] [stdout]     |                       the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 351 |     pub fn iter_steps(&mut self) -> SolverSteps<'_> {
[INFO] [stdout]     |                                                ++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Duration` and `Instant`
[INFO] [stdout]  --> src/main.rs:1:17
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::time::{Duration, Instant};
[INFO] [stdout]   |                 ^^^^^^^^  ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `bumpalo::Bump`
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use bumpalo::Bump;
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::thread::sleep`
[INFO] [stdout]  --> src/main.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::thread::sleep;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `itertools::Itertools`
[INFO] [stdout]  --> src/main.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use itertools::Itertools;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `SolverStep`
[INFO] [stdout]  --> src/main.rs:8:48
[INFO] [stdout]   |
[INFO] [stdout] 8 |     ExactCoverSolver, ExactCoverRepresentable, SolverStep
[INFO] [stdout]   |                                                ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 3.50s
[INFO] running `Command { std: "docker" "inspect" "1ddbc96a6b99c9c8f282413e24b3e096b7daa5722a65ad73ece82b4694088915", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1ddbc96a6b99c9c8f282413e24b3e096b7daa5722a65ad73ece82b4694088915", kill_on_drop: false }`
[INFO] [stdout] 1ddbc96a6b99c9c8f282413e24b3e096b7daa5722a65ad73ece82b4694088915
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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=forbid" "-e" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:845e597a41426bbf2703be69acdb67d10b6de511142d05cba7bbe119c898b2c7" "/opt/rustwide/cargo-home/bin/cargo" "+0d162b25edd5bf0dba9a22e83b614f1113e90474" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bc6c0eb2d87f61d9f1c082e640b1e1e0f2b518b7bb34e984cf3dfca638046cf8
[INFO] running `Command { std: "docker" "start" "-a" "bc6c0eb2d87f61d9f1c082e640b1e1e0f2b518b7bb34e984cf3dfca638046cf8", kill_on_drop: false }`
[INFO] [stdout] warning: unused import: `ExactCoverSolver`
[INFO] [stdout]  --> src/solver/representable.rs:2:17
[INFO] [stdout]   |
[INFO] [stdout] 2 |     ExactCover, ExactCoverSolver, ExactCoverProblem, PartialCover
[INFO] [stdout]   |                 ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `arrayvec::ArrayVec`
[INFO] [stdout]  --> src/solver/solver.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use arrayvec::ArrayVec;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `itertools::Itertools`
[INFO] [stdout]  --> src/solver/solver.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use itertools::Itertools;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type `ENTRY_IDX` should have an upper camel case name
[INFO] [stdout]   --> src/solver/solver.rs:83:6
[INFO] [stdout]    |
[INFO] [stdout] 83 | type ENTRY_IDX = u16;
[INFO] [stdout]    |      ^^^^^^^^^ help: convert the identifier to upper camel case: `EntryIdx`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_camel_case_types)]` (part of `#[warn(nonstandard_style)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type `COL_OR_ROW_IDX` should have an upper camel case name
[INFO] [stdout]   --> src/solver/solver.rs:84:6
[INFO] [stdout]    |
[INFO] [stdout] 84 | type COL_OR_ROW_IDX = u16;
[INFO] [stdout]    |      ^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `ColOrRowIdx`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `ExactCoverProblemError` and `SparseBinaryMatrix`
[INFO] [stdout]   --> src/solver/mod.rs:12:38
[INFO] [stdout]    |
[INFO] [stdout] 12 | pub use problem::{ExactCoverProblem, ExactCoverProblemError,
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 13 | SparseBinaryMatrix};
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `ExactCoverSolver`
[INFO] [stdout]  --> src/problems/n_queens.rs:7:21
[INFO] [stdout]   |
[INFO] [stdout] 7 |         ExactCover, ExactCoverSolver, ExactCoverProblem, PartialCover,
[INFO] [stdout]   |                     ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `o_rows` and `empty_rows` are never read
[INFO] [stdout]   --> src/solver/solver.rs:59:5
[INFO] [stdout]    |
[INFO] [stdout] 54 | pub struct ExactCoverSolver {
[INFO] [stdout]    |            ---------------- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 59 |     o_rows: Vec<usize>,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 64 |     empty_rows: Vec<usize>,
[INFO] [stdout]    |     ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `ExactCoverSolver` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `MAX_COLS` is never used
[INFO] [stdout]   --> src/solver/solver.rs:73:7
[INFO] [stdout]    |
[INFO] [stdout] 73 | const MAX_COLS: usize = 4096;
[INFO] [stdout]    |       ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `MAX_ROWS` is never used
[INFO] [stdout]   --> src/solver/solver.rs:74:7
[INFO] [stdout]    |
[INFO] [stdout] 74 | const MAX_ROWS: usize = 4096;
[INFO] [stdout]    |       ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `MAX_ONES` is never used
[INFO] [stdout]   --> src/solver/solver.rs:75:7
[INFO] [stdout]    |
[INFO] [stdout] 75 | const MAX_ONES: usize = 65536 - MAX_COLS;
[INFO] [stdout]    |       ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `ENTRY_IDX` is never used
[INFO] [stdout]   --> src/solver/solver.rs:83:6
[INFO] [stdout]    |
[INFO] [stdout] 83 | type ENTRY_IDX = u16;
[INFO] [stdout]    |      ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `COL_OR_ROW_IDX` is never used
[INFO] [stdout]   --> src/solver/solver.rs:84:6
[INFO] [stdout]    |
[INFO] [stdout] 84 | type COL_OR_ROW_IDX = u16;
[INFO] [stdout]    |      ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/solver/solver.rs:346:27
[INFO] [stdout]     |
[INFO] [stdout] 346 |     pub fn iter_solutions(&mut self) -> Solutions {
[INFO] [stdout]     |                           ^^^^^^^^^     ^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                           |
[INFO] [stdout]     |                           the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]     = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 346 |     pub fn iter_solutions(&mut self) -> Solutions<'_> {
[INFO] [stdout]     |                                                  ++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling exact_cover_solver v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/solver/solver.rs:351:23
[INFO] [stdout]     |
[INFO] [stdout] 351 |     pub fn iter_steps(&mut self) -> SolverSteps {
[INFO] [stdout]     |                       ^^^^^^^^^     ^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                       |
[INFO] [stdout]     |                       the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 351 |     pub fn iter_steps(&mut self) -> SolverSteps<'_> {
[INFO] [stdout]     |                                                ++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Duration` and `Instant`
[INFO] [stdout]  --> src/main.rs:1:17
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::time::{Duration, Instant};
[INFO] [stdout]   |                 ^^^^^^^^  ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `bumpalo::Bump`
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use bumpalo::Bump;
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::thread::sleep`
[INFO] [stdout]  --> src/main.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::thread::sleep;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `itertools::Itertools`
[INFO] [stdout]  --> src/main.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use itertools::Itertools;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `SolverStep`
[INFO] [stdout]  --> src/main.rs:8:48
[INFO] [stdout]   |
[INFO] [stdout] 8 |     ExactCoverSolver, ExactCoverRepresentable, SolverStep
[INFO] [stdout]   |                                                ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `ExactCoverSolver`
[INFO] [stdout]  --> src/solver/representable.rs:2:17
[INFO] [stdout]   |
[INFO] [stdout] 2 |     ExactCover, ExactCoverSolver, ExactCoverProblem, PartialCover
[INFO] [stdout]   |                 ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `arrayvec::ArrayVec`
[INFO] [stdout]  --> src/solver/solver.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use arrayvec::ArrayVec;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `itertools::Itertools`
[INFO] [stdout]  --> src/solver/solver.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use itertools::Itertools;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type `ENTRY_IDX` should have an upper camel case name
[INFO] [stdout]   --> src/solver/solver.rs:83:6
[INFO] [stdout]    |
[INFO] [stdout] 83 | type ENTRY_IDX = u16;
[INFO] [stdout]    |      ^^^^^^^^^ help: convert the identifier to upper camel case: `EntryIdx`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_camel_case_types)]` (part of `#[warn(nonstandard_style)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type `COL_OR_ROW_IDX` should have an upper camel case name
[INFO] [stdout]   --> src/solver/solver.rs:84:6
[INFO] [stdout]    |
[INFO] [stdout] 84 | type COL_OR_ROW_IDX = u16;
[INFO] [stdout]    |      ^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `ColOrRowIdx`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `ExactCoverRepresentable` and `problems::NQueens`
[INFO] [stdout]  --> src/solver/tests/cases.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 |     problems::NQueens,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 8 |     solver::{ExactCover, ExactCoverSolver, ExactCoverRepresentable,
[INFO] [stdout]   |                                            ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `ExactCoverProblemError`
[INFO] [stdout]   --> src/solver/mod.rs:12:38
[INFO] [stdout]    |
[INFO] [stdout] 12 | pub use problem::{ExactCoverProblem, ExactCoverProblemError,
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `o_rows` and `empty_rows` are never read
[INFO] [stdout]   --> src/solver/solver.rs:59:5
[INFO] [stdout]    |
[INFO] [stdout] 54 | pub struct ExactCoverSolver {
[INFO] [stdout]    |            ---------------- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 59 |     o_rows: Vec<usize>,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 64 |     empty_rows: Vec<usize>,
[INFO] [stdout]    |     ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `ExactCoverSolver` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `MAX_COLS` is never used
[INFO] [stdout]   --> src/solver/solver.rs:73:7
[INFO] [stdout]    |
[INFO] [stdout] 73 | const MAX_COLS: usize = 4096;
[INFO] [stdout]    |       ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `MAX_ROWS` is never used
[INFO] [stdout]   --> src/solver/solver.rs:74:7
[INFO] [stdout]    |
[INFO] [stdout] 74 | const MAX_ROWS: usize = 4096;
[INFO] [stdout]    |       ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `MAX_ONES` is never used
[INFO] [stdout]   --> src/solver/solver.rs:75:7
[INFO] [stdout]    |
[INFO] [stdout] 75 | const MAX_ONES: usize = 65536 - MAX_COLS;
[INFO] [stdout]    |       ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `ENTRY_IDX` is never used
[INFO] [stdout]   --> src/solver/solver.rs:83:6
[INFO] [stdout]    |
[INFO] [stdout] 83 | type ENTRY_IDX = u16;
[INFO] [stdout]    |      ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `COL_OR_ROW_IDX` is never used
[INFO] [stdout]   --> src/solver/solver.rs:84:6
[INFO] [stdout]    |
[INFO] [stdout] 84 | type COL_OR_ROW_IDX = u16;
[INFO] [stdout]    |      ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/solver/solver.rs:346:27
[INFO] [stdout]     |
[INFO] [stdout] 346 |     pub fn iter_solutions(&mut self) -> Solutions {
[INFO] [stdout]     |                           ^^^^^^^^^     ^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                           |
[INFO] [stdout]     |                           the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]     = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 346 |     pub fn iter_solutions(&mut self) -> Solutions<'_> {
[INFO] [stdout]     |                                                  ++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/solver/solver.rs:351:23
[INFO] [stdout]     |
[INFO] [stdout] 351 |     pub fn iter_steps(&mut self) -> SolverSteps {
[INFO] [stdout]     |                       ^^^^^^^^^     ^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                       |
[INFO] [stdout]     |                       the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 351 |     pub fn iter_steps(&mut self) -> SolverSteps<'_> {
[INFO] [stdout]     |                                                ++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 1.21s
[INFO] running `Command { std: "docker" "inspect" "bc6c0eb2d87f61d9f1c082e640b1e1e0f2b518b7bb34e984cf3dfca638046cf8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bc6c0eb2d87f61d9f1c082e640b1e1e0f2b518b7bb34e984cf3dfca638046cf8", kill_on_drop: false }`
[INFO] [stdout] bc6c0eb2d87f61d9f1c082e640b1e1e0f2b518b7bb34e984cf3dfca638046cf8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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=forbid" "-e" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:845e597a41426bbf2703be69acdb67d10b6de511142d05cba7bbe119c898b2c7" "/opt/rustwide/cargo-home/bin/cargo" "+0d162b25edd5bf0dba9a22e83b614f1113e90474" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 5e1c7d3c9dcbf0572555cf862548581d51571c4f72108a96cbcb6a82573139a3
[INFO] running `Command { std: "docker" "start" "-a" "5e1c7d3c9dcbf0572555cf862548581d51571c4f72108a96cbcb6a82573139a3", kill_on_drop: false }`
[INFO] [stderr] warning: unused import: `ExactCoverSolver`
[INFO] [stderr]  --> src/solver/representable.rs:2:17
[INFO] [stderr]   |
[INFO] [stderr] 2 |     ExactCover, ExactCoverSolver, ExactCoverProblem, PartialCover
[INFO] [stderr]   |                 ^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `arrayvec::ArrayVec`
[INFO] [stderr]  --> src/solver/solver.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use arrayvec::ArrayVec;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `itertools::Itertools`
[INFO] [stderr]  --> src/solver/solver.rs:3:5
[INFO] [stderr]   |
[INFO] [stderr] 3 | use itertools::Itertools;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: type `ENTRY_IDX` should have an upper camel case name
[INFO] [stderr]   --> src/solver/solver.rs:83:6
[INFO] [stderr]    |
[INFO] [stderr] 83 | type ENTRY_IDX = u16;
[INFO] [stderr]    |      ^^^^^^^^^ help: convert the identifier to upper camel case: `EntryIdx`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(non_camel_case_types)]` (part of `#[warn(nonstandard_style)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: type `COL_OR_ROW_IDX` should have an upper camel case name
[INFO] [stderr]   --> src/solver/solver.rs:84:6
[INFO] [stderr]    |
[INFO] [stderr] 84 | type COL_OR_ROW_IDX = u16;
[INFO] [stderr]    |      ^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `ColOrRowIdx`
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `ExactCoverProblemError` and `SparseBinaryMatrix`
[INFO] [stderr]   --> src/solver/mod.rs:12:38
[INFO] [stderr]    |
[INFO] [stderr] 12 | pub use problem::{ExactCoverProblem, ExactCoverProblemError,
[INFO] [stderr]    |                                      ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 13 | SparseBinaryMatrix};
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `ExactCoverSolver`
[INFO] [stderr]  --> src/problems/n_queens.rs:7:21
[INFO] [stderr]   |
[INFO] [stderr] 7 |         ExactCover, ExactCoverSolver, ExactCoverProblem, PartialCover,
[INFO] [stderr]   |                     ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: fields `o_rows` and `empty_rows` are never read
[INFO] [stderr]   --> src/solver/solver.rs:59:5
[INFO] [stderr]    |
[INFO] [stderr] 54 | pub struct ExactCoverSolver {
[INFO] [stderr]    |            ---------------- fields in this struct
[INFO] [stderr] ...
[INFO] [stderr] 59 |     o_rows: Vec<usize>,
[INFO] [stderr]    |     ^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 64 |     empty_rows: Vec<usize>,
[INFO] [stderr]    |     ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `ExactCoverSolver` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stderr]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: constant `MAX_COLS` is never used
[INFO] [stderr]   --> src/solver/solver.rs:73:7
[INFO] [stderr]    |
[INFO] [stderr] 73 | const MAX_COLS: usize = 4096;
[INFO] [stderr]    |       ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: constant `MAX_ROWS` is never used
[INFO] [stderr]   --> src/solver/solver.rs:74:7
[INFO] [stderr]    |
[INFO] [stderr] 74 | const MAX_ROWS: usize = 4096;
[INFO] [stderr]    |       ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: constant `MAX_ONES` is never used
[INFO] [stderr]   --> src/solver/solver.rs:75:7
[INFO] [stderr]    |
[INFO] [stderr] 75 | const MAX_ONES: usize = 65536 - MAX_COLS;
[INFO] [stderr]    |       ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: type alias `ENTRY_IDX` is never used
[INFO] [stderr]   --> src/solver/solver.rs:83:6
[INFO] [stderr]    |
[INFO] [stderr] 83 | type ENTRY_IDX = u16;
[INFO] [stderr]    |      ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: type alias `COL_OR_ROW_IDX` is never used
[INFO] [stderr]   --> src/solver/solver.rs:84:6
[INFO] [stderr]    |
[INFO] [stderr] 84 | type COL_OR_ROW_IDX = u16;
[INFO] [stderr]    |      ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stderr]    --> src/solver/solver.rs:346:27
[INFO] [stderr]     |
[INFO] [stderr] 346 |     pub fn iter_solutions(&mut self) -> Solutions {
[INFO] [stderr]     |                           ^^^^^^^^^     ^^^^^^^^^ the same lifetime is hidden here
[INFO] [stderr]     |                           |
[INFO] [stderr]     |                           the lifetime is elided here
[INFO] [stderr]     |
[INFO] [stderr]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stderr]     = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stderr] help: use `'_` for type paths
[INFO] [stderr]     |
[INFO] [stderr] 346 |     pub fn iter_solutions(&mut self) -> Solutions<'_> {
[INFO] [stderr]     |                                                  ++++
[INFO] [stderr] 
[INFO] [stderr] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stderr]    --> src/solver/solver.rs:351:23
[INFO] [stderr]     |
[INFO] [stderr] 351 |     pub fn iter_steps(&mut self) -> SolverSteps {
[INFO] [stderr]     |                       ^^^^^^^^^     ^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stderr]     |                       |
[INFO] [stderr]     |                       the lifetime is elided here
[INFO] [stderr]     |
[INFO] [stderr]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stderr] help: use `'_` for type paths
[INFO] [stderr]     |
[INFO] [stderr] 351 |     pub fn iter_steps(&mut self) -> SolverSteps<'_> {
[INFO] [stderr]     |                                                ++++
[INFO] [stderr] 
[INFO] [stderr] warning: `exact_cover_solver` (lib) generated 15 warnings (run `cargo fix --lib -p exact_cover_solver` to apply 7 suggestions)
[INFO] [stderr] warning: unused imports: `Duration` and `Instant`
[INFO] [stderr]  --> src/main.rs:1:17
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::time::{Duration, Instant};
[INFO] [stderr]   |                 ^^^^^^^^  ^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `bumpalo::Bump`
[INFO] [stderr]  --> src/main.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use bumpalo::Bump;
[INFO] [stderr]   |     ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::thread::sleep`
[INFO] [stderr]  --> src/main.rs:4:5
[INFO] [stderr]   |
[INFO] [stderr] 4 | use std::thread::sleep;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `itertools::Itertools`
[INFO] [stderr]  --> src/main.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use itertools::Itertools;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `SolverStep`
[INFO] [stderr]  --> src/main.rs:8:48
[INFO] [stderr]   |
[INFO] [stderr] 8 |     ExactCoverSolver, ExactCoverRepresentable, SolverStep
[INFO] [stderr]   |                                                ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `ExactCoverRepresentable` and `problems::NQueens`
[INFO] [stderr]  --> src/solver/tests/cases.rs:7:5
[INFO] [stderr]   |
[INFO] [stderr] 7 |     problems::NQueens,
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 8 |     solver::{ExactCover, ExactCoverSolver, ExactCoverRepresentable,
[INFO] [stderr]   |                                            ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `ExactCoverProblemError`
[INFO] [stderr]   --> src/solver/mod.rs:12:38
[INFO] [stderr]    |
[INFO] [stderr] 12 | pub use problem::{ExactCoverProblem, ExactCoverProblemError,
[INFO] [stderr]    |                                      ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: `exact_cover_solver` (bin "exact_cover_solver" test) generated 5 warnings (run `cargo fix --bin "exact_cover_solver" -p exact_cover_solver --tests` to apply 5 suggestions)
[INFO] [stderr] warning: `exact_cover_solver` (lib test) generated 15 warnings (13 duplicates) (run `cargo fix --lib -p exact_cover_solver --tests` to apply 2 suggestions)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.09s
[INFO] [stderr]      Running unittests src/lib.rs (/opt/rustwide/target/debug/deps/exact_cover_solver-956e627b25cd8c08)
[INFO] [stdout] 
[INFO] [stdout] running 15 tests
[INFO] [stdout] test problems::n_queens::test::n_queens_0_equal_to_brute_force ... ok
[INFO] [stdout] test problems::n_queens::test::n_queens_2_equal_to_brute_force ... ok
[INFO] [stdout] test problems::n_queens::test::n_queens_4_equal_to_brute_force ... ok
[INFO] [stdout] test problems::n_queens::test::n_queens_1_equal_to_brute_force ... ok
[INFO] [stdout] test problems::n_queens::test::n_queens_5_equal_to_brute_force ... ok
[INFO] [stdout] test solver::tests::cases::check_solutions_knuth_simple ... ok
[INFO] [stdout] test solver::tests::cases::check_solutions_zero_by_zero ... ok
[INFO] [stdout] test solver::tests::cases::check_solutions_zero_rows_three_cols_all_secondary ... ok
[INFO] [stdout] test solver::tests::cases::check_solutions_zero_rows_three_cols ... ok
[INFO] [stdout] test problems::n_queens::test::n_queens_3_equal_to_brute_force ... ok
[INFO] [stdout] test solver::tests::cases::check_solutions_three_rows_zero_cols ... FAILED
[INFO] [stdout] test problems::n_queens::test::n_queens_6_equal_to_brute_force ... ok
[INFO] [stdout] test solver::problem::test::test_ordered_points_rows ... ok
[INFO] [stdout] test problems::n_queens::test::n_queens_7_equal_to_brute_force ... ok
[INFO] [stdout] test problems::n_queens::test::n_queens_8_equal_to_brute_force ... ok
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout] 
[INFO] [stdout] ---- solver::tests::cases::check_solutions_three_rows_zero_cols stdout ----
[INFO] [stdout] 
[INFO] [stdout] thread 'solver::tests::cases::check_solutions_three_rows_zero_cols' (28) panicked at src/solver/problem.rs:79:9:
[INFO] [stdout] attempt to subtract with overflow
[INFO] [stdout] stack backtrace:
[INFO] [stdout]    0:     0x608e766333c2 - std[3b51380354919863]::backtrace_rs::backtrace::libunwind::trace
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/../../backtrace/src/backtrace/libunwind.rs:117:9
[INFO] [stdout]    1:     0x608e766333c2 - std[3b51380354919863]::backtrace_rs::backtrace::trace_unsynchronized::<std[3b51380354919863]::sys::backtrace::_print_fmt::{closure#1}>
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/../../backtrace/src/backtrace/mod.rs:66:14
[INFO] [stdout]    2:     0x608e766333c2 - std[3b51380354919863]::sys::backtrace::_print_fmt
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/sys/backtrace.rs:74:9
[INFO] [stdout]    3:     0x608e766333c2 - <<std[3b51380354919863]::sys::backtrace::BacktraceLock>::print::DisplayBacktrace as core[27de1724e4349be2]::fmt::Display>::fmt
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/sys/backtrace.rs:44:26
[INFO] [stdout]    4:     0x608e76647bfa - <core[27de1724e4349be2]::fmt::rt::Argument>::fmt
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/core/src/fmt/rt.rs:152:76
[INFO] [stdout]    5:     0x608e76647bfa - core[27de1724e4349be2]::fmt::write
[INFO] [stdout]    6:     0x608e766381c6 - std[3b51380354919863]::io::default_write_fmt::<alloc[a57f19327c0ad893]::vec::Vec<u8>>
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/io/mod.rs:639:11
[INFO] [stdout]    7:     0x608e766381c6 - <alloc[a57f19327c0ad893]::vec::Vec<u8> as std[3b51380354919863]::io::Write>::write_fmt
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/io/mod.rs:1994:13
[INFO] [stdout]    8:     0x608e76611b5f - <std[3b51380354919863]::sys::backtrace::BacktraceLock>::print
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/sys/backtrace.rs:47:9
[INFO] [stdout]    9:     0x608e76611b5f - std[3b51380354919863]::panicking::default_hook::{closure#0}
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/panicking.rs:292:27
[INFO] [stdout]   10:     0x608e7662b6a9 - std[3b51380354919863]::panicking::default_hook
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/panicking.rs:316:9
[INFO] [stdout]   11:     0x608e765c546e - <alloc[a57f19327c0ad893]::boxed::Box<dyn for<'a, 'b> core[27de1724e4349be2]::ops::function::Fn<(&'a std[3b51380354919863]::panic::PanicHookInfo<'b>,), Output = ()> + core[27de1724e4349be2]::marker::Sync + core[27de1724e4349be2]::marker::Send> as core[27de1724e4349be2]::ops::function::Fn<(&std[3b51380354919863]::panic::PanicHookInfo,)>>::call
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/alloc/src/boxed.rs:2220:9
[INFO] [stdout]   12:     0x608e765c546e - test[182b2e79ecd7bbd9]::test_main_with_exit_callback::<test[182b2e79ecd7bbd9]::test_main::{closure#0}>::{closure#0}
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/test/src/lib.rs:145:21
[INFO] [stdout]   13:     0x608e7662b862 - <alloc[a57f19327c0ad893]::boxed::Box<dyn for<'a, 'b> core[27de1724e4349be2]::ops::function::Fn<(&'a std[3b51380354919863]::panic::PanicHookInfo<'b>,), Output = ()> + core[27de1724e4349be2]::marker::Sync + core[27de1724e4349be2]::marker::Send> as core[27de1724e4349be2]::ops::function::Fn<(&std[3b51380354919863]::panic::PanicHookInfo,)>>::call
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/alloc/src/boxed.rs:2220:9
[INFO] [stdout]   14:     0x608e7662b862 - std[3b51380354919863]::panicking::panic_with_hook
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/panicking.rs:833:13
[INFO] [stdout]   15:     0x608e76611c4a - std[3b51380354919863]::panicking::panic_handler::{closure#0}
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/panicking.rs:691:13
[INFO] [stdout]   16:     0x608e76606e99 - std[3b51380354919863]::sys::backtrace::__rust_end_short_backtrace::<std[3b51380354919863]::panicking::panic_handler::{closure#0}, !>
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/sys/backtrace.rs:182:18
[INFO] [stdout]   17:     0x608e76612a6d - __rustc[d79c0ace40940972]::rust_begin_unwind
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/panicking.rs:689:5
[INFO] [stdout]   18:     0x608e766482cc - core[27de1724e4349be2]::panicking::panic_fmt
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/core/src/panicking.rs:80:14
[INFO] [stdout]   19:     0x608e76649349 - core[27de1724e4349be2]::panicking::panic_const::panic_const_sub_overflow
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/core/src/panicking.rs:175:17
[INFO] [stdout]   20:     0x608e765b2311 - <exact_cover_solver[fa31a6353cdea1bc]::solver::problem::ExactCoverProblem>::primary_columns
[INFO] [stdout]                                at /opt/rustwide/workdir/src/solver/problem.rs:79:9
[INFO] [stdout]   21:     0x608e765a3317 - <exact_cover_solver[fa31a6353cdea1bc]::solver::solver::ExactCoverSolver>::new
[INFO] [stdout]                                at /opt/rustwide/workdir/src/solver/solver.rs:112:36
[INFO] [stdout]   22:     0x608e765aed19 - <exact_cover_solver[fa31a6353cdea1bc]::solver::tests::cases::ThreeRowsZeroCols as exact_cover_solver[fa31a6353cdea1bc]::solver::tests::cases::TestCase>::assert_solution_match
[INFO] [stdout]                                at /opt/rustwide/workdir/src/solver/tests/cases.rs:17:27
[INFO] [stdout]   23:     0x608e765ac82b - exact_cover_solver[fa31a6353cdea1bc]::solver::tests::cases::check_solutions_three_rows_zero_cols
[INFO] [stdout]                                at /opt/rustwide/workdir/src/solver/tests/cases.rs:117:76
[INFO] [stdout]   24:     0x608e765abd57 - exact_cover_solver[fa31a6353cdea1bc]::solver::tests::cases::check_solutions_three_rows_zero_cols::{closure#0}
[INFO] [stdout]                                at /opt/rustwide/workdir/src/solver/tests/cases.rs:117:50
[INFO] [stdout]   25:     0x608e765ae596 - <exact_cover_solver[fa31a6353cdea1bc]::solver::tests::cases::check_solutions_three_rows_zero_cols::{closure#0} as core[27de1724e4349be2]::ops::function::FnOnce<()>>::call_once
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/core/src/ops/function.rs:250:5
[INFO] [stdout]   26:     0x608e765b981b - <fn() -> core[27de1724e4349be2]::result::Result<(), alloc[a57f19327c0ad893]::string::String> as core[27de1724e4349be2]::ops::function::FnOnce<()>>::call_once
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/core/src/ops/function.rs:250:5
[INFO] [stdout]   27:     0x608e765b981b - test[182b2e79ecd7bbd9]::__rust_begin_short_backtrace::<core[27de1724e4349be2]::result::Result<(), alloc[a57f19327c0ad893]::string::String>, fn() -> core[27de1724e4349be2]::result::Result<(), alloc[a57f19327c0ad893]::string::String>>
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/test/src/lib.rs:663:18
[INFO] [stdout]   28:     0x608e765c607a - test[182b2e79ecd7bbd9]::run_test_in_process::{closure#0}
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/test/src/lib.rs:686:74
[INFO] [stdout]   29:     0x608e765c607a - <core[27de1724e4349be2]::panic::unwind_safe::AssertUnwindSafe<test[182b2e79ecd7bbd9]::run_test_in_process::{closure#0}> as core[27de1724e4349be2]::ops::function::FnOnce<()>>::call_once
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/core/src/panic/unwind_safe.rs:274:9
[INFO] [stdout]   30:     0x608e765c607a - std[3b51380354919863]::panicking::catch_unwind::do_call::<core[27de1724e4349be2]::panic::unwind_safe::AssertUnwindSafe<test[182b2e79ecd7bbd9]::run_test_in_process::{closure#0}>, core[27de1724e4349be2]::result::Result<(), alloc[a57f19327c0ad893]::string::String>>
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/panicking.rs:581:40
[INFO] [stdout]   31:     0x608e765c607a - std[3b51380354919863]::panicking::catch_unwind::<core[27de1724e4349be2]::result::Result<(), alloc[a57f19327c0ad893]::string::String>, core[27de1724e4349be2]::panic::unwind_safe::AssertUnwindSafe<test[182b2e79ecd7bbd9]::run_test_in_process::{closure#0}>>
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/panicking.rs:544:19
[INFO] [stdout]   32:     0x608e765c607a - std[3b51380354919863]::panic::catch_unwind::<core[27de1724e4349be2]::panic::unwind_safe::AssertUnwindSafe<test[182b2e79ecd7bbd9]::run_test_in_process::{closure#0}>, core[27de1724e4349be2]::result::Result<(), alloc[a57f19327c0ad893]::string::String>>
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/panic.rs:359:14
[INFO] [stdout]   33:     0x608e765c607a - test[182b2e79ecd7bbd9]::run_test_in_process
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/test/src/lib.rs:686:27
[INFO] [stdout]   34:     0x608e765c607a - test[182b2e79ecd7bbd9]::run_test::{closure#0}
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/test/src/lib.rs:607:43
[INFO] [stdout]   35:     0x608e765c1624 - test[182b2e79ecd7bbd9]::run_test::{closure#1}
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/test/src/lib.rs:637:41
[INFO] [stdout]   36:     0x608e765c1624 - std[3b51380354919863]::sys::backtrace::__rust_begin_short_backtrace::<test[182b2e79ecd7bbd9]::run_test::{closure#1}, ()>
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/sys/backtrace.rs:166:18
[INFO] [stdout]   37:     0x608e765c8b72 - std[3b51380354919863]::thread::lifecycle::spawn_unchecked::<test[182b2e79ecd7bbd9]::run_test::{closure#1}, ()>::{closure#1}::{closure#0}
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/thread/lifecycle.rs:91:13
[INFO] [stdout]   38:     0x608e765c8b72 - <core[27de1724e4349be2]::panic::unwind_safe::AssertUnwindSafe<std[3b51380354919863]::thread::lifecycle::spawn_unchecked<test[182b2e79ecd7bbd9]::run_test::{closure#1}, ()>::{closure#1}::{closure#0}> as core[27de1724e4349be2]::ops::function::FnOnce<()>>::call_once
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/core/src/panic/unwind_safe.rs:274:9
[INFO] [stdout]   39:     0x608e765c8b72 - std[3b51380354919863]::panicking::catch_unwind::do_call::<core[27de1724e4349be2]::panic::unwind_safe::AssertUnwindSafe<std[3b51380354919863]::thread::lifecycle::spawn_unchecked<test[182b2e79ecd7bbd9]::run_test::{closure#1}, ()>::{closure#1}::{closure#0}>, ()>
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/panicking.rs:581:40
[INFO] [stdout]   40:     0x608e765c8b72 - std[3b51380354919863]::panicking::catch_unwind::<(), core[27de1724e4349be2]::panic::unwind_safe::AssertUnwindSafe<std[3b51380354919863]::thread::lifecycle::spawn_unchecked<test[182b2e79ecd7bbd9]::run_test::{closure#1}, ()>::{closure#1}::{closure#0}>>
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/panicking.rs:544:19
[INFO] [stdout]   41:     0x608e765c8b72 - std[3b51380354919863]::panic::catch_unwind::<core[27de1724e4349be2]::panic::unwind_safe::AssertUnwindSafe<std[3b51380354919863]::thread::lifecycle::spawn_unchecked<test[182b2e79ecd7bbd9]::run_test::{closure#1}, ()>::{closure#1}::{closure#0}>, ()>
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/panic.rs:359:14
[INFO] [stdout]   42:     0x608e765c8b72 - std[3b51380354919863]::thread::lifecycle::spawn_unchecked::<test[182b2e79ecd7bbd9]::run_test::{closure#1}, ()>::{closure#1}
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/thread/lifecycle.rs:89:26
[INFO] [stdout]   43:     0x608e765c8b72 - <std[3b51380354919863]::thread::lifecycle::spawn_unchecked<test[182b2e79ecd7bbd9]::run_test::{closure#1}, ()>::{closure#1} as core[27de1724e4349be2]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/core/src/ops/function.rs:250:5
[INFO] [stdout]   44:     0x608e76632c6f - <alloc[a57f19327c0ad893]::boxed::Box<dyn core[27de1724e4349be2]::ops::function::FnOnce<(), Output = ()> + core[27de1724e4349be2]::marker::Send> as core[27de1724e4349be2]::ops::function::FnOnce<()>>::call_once
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/alloc/src/boxed.rs:2206:9
[INFO] [stdout]   45:     0x608e76632c6f - <std[3b51380354919863]::sys::thread::unix::Thread>::new::thread_start
[INFO] [stdout]                                at /rustc/0d162b25edd5bf0dba9a22e83b614f1113e90474/library/std/src/sys/thread/unix.rs:119:17
[INFO] [stdout]   46:     0x7c3a7cdb0aa4 - <unknown>
[INFO] [stdout]   47:     0x7c3a7ce3da64 - clone
[INFO] [stdout]   48:                0x0 - <unknown>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout]     solver::tests::cases::check_solutions_three_rows_zero_cols
[INFO] [stdout] 
[INFO] [stdout] test result: FAILED. 14 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.77s
[INFO] [stdout] 
[INFO] [stderr] error: test failed, to rerun pass `--lib`
[INFO] running `Command { std: "docker" "inspect" "5e1c7d3c9dcbf0572555cf862548581d51571c4f72108a96cbcb6a82573139a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5e1c7d3c9dcbf0572555cf862548581d51571c4f72108a96cbcb6a82573139a3", kill_on_drop: false }`
[INFO] [stdout] 5e1c7d3c9dcbf0572555cf862548581d51571c4f72108a96cbcb6a82573139a3
