[INFO] cloning repository https://github.com/02alexander/maze-solver
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/02alexander/maze-solver" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F02alexander%2Fmaze-solver", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F02alexander%2Fmaze-solver'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 4303321d53fdbde07fa4a170dc2621ef0f8172fb
[INFO] checking 02alexander/maze-solver against master#90442458ac46b1d5eed752c316da25450f67285b for pr-81477
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F02alexander%2Fmaze-solver" "/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/02alexander/maze-solver on toolchain 90442458ac46b1d5eed752c316da25450f67285b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/02alexander/maze-solver
[INFO] finished tweaking git repo https://github.com/02alexander/maze-solver
[INFO] tweaked toml for git repo https://github.com/02alexander/maze-solver written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/02alexander/maze-solver already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:ea7d7bff36b2ba8ce4de8bba1d2dea90376bc481f1a945a913994a8c492e40c1" "/opt/rustwide/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2337924ed05d8ba4ae819f74c9cd700c63b3b9a4c0420df223c446dbee01596b
[INFO] running `Command { std: "docker" "start" "-a" "2337924ed05d8ba4ae819f74c9cd700c63b3b9a4c0420df223c446dbee01596b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2337924ed05d8ba4ae819f74c9cd700c63b3b9a4c0420df223c446dbee01596b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2337924ed05d8ba4ae819f74c9cd700c63b3b9a4c0420df223c446dbee01596b", kill_on_drop: false }`
[INFO] [stdout] 2337924ed05d8ba4ae819f74c9cd700c63b3b9a4c0420df223c446dbee01596b
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:ea7d7bff36b2ba8ce4de8bba1d2dea90376bc481f1a945a913994a8c492e40c1" "/opt/rustwide/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a30f4b5b9777df2851c529591805470520cc537bea88306fd15bc599a05affa8
[INFO] running `Command { std: "docker" "start" "-a" "a30f4b5b9777df2851c529591805470520cc537bea88306fd15bc599a05affa8", kill_on_drop: false }`
[INFO] [stderr]    Compiling cc v1.0.18
[INFO] [stderr]     Checking libc v0.2.42
[INFO] [stderr]    Compiling miniz-sys v0.1.10
[INFO] [stderr]     Checking flate2 v0.2.20
[INFO] [stderr]     Checking imagefmt v4.0.0
[INFO] [stderr]     Checking maze-solver v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused imports: `read`, `write`
[INFO] [stdout]  --> src/main.rs:3:16
[INFO] [stdout]   |
[INFO] [stdout] 3 | use imagefmt::{read, write, ColFmt, ColType};
[INFO] [stdout]   |                ^^^^  ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::mem::drop`
[INFO] [stdout]  --> src/tree.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::mem::drop;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Node`
[INFO] [stdout]  --> src/path_to_end.rs:3:35
[INFO] [stdout]   |
[INFO] [stdout] 3 | use super::tree::{QuaternaryTree, Node, Link};
[INFO] [stdout]   |                                   ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `read`, `write`
[INFO] [stdout]  --> src/main.rs:3:16
[INFO] [stdout]   |
[INFO] [stdout] 3 | use imagefmt::{read, write, ColFmt, ColType};
[INFO] [stdout]   |                ^^^^  ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::mem::drop`
[INFO] [stdout]  --> src/tree.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::mem::drop;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tree.rs:41:8
[INFO] [stdout]    |
[INFO] [stdout] 41 |             let mut cur = &mut *next.take().unwrap();
[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/tree.rs:41:8
[INFO] [stdout]    |
[INFO] [stdout] 41 |             let mut cur = &mut *next.take().unwrap();
[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 `Result` that must be used
[INFO] [stdout]   --> src/main.rs:20:2
[INFO] [stdout]    |
[INFO] [stdout] 20 |     imagefmt::write("out.bmp", maze.width, maze.height, ColFmt::RGB, &pixels, ColType::Auto);
[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] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:20:2
[INFO] [stdout]    |
[INFO] [stdout] 20 |     imagefmt::write("out.bmp", maze.width, maze.height, ColFmt::RGB, &pixels, ColType::Auto);
[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] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.10s
[INFO] running `Command { std: "docker" "inspect" "a30f4b5b9777df2851c529591805470520cc537bea88306fd15bc599a05affa8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a30f4b5b9777df2851c529591805470520cc537bea88306fd15bc599a05affa8", kill_on_drop: false }`
[INFO] [stdout] a30f4b5b9777df2851c529591805470520cc537bea88306fd15bc599a05affa8