[INFO] updating cached repository https://github.com/02alexander/maze-solver
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 4303321d53fdbde07fa4a170dc2621ef0f8172fb
[INFO] checking 02alexander/maze-solver against master#45d050cde277b22a755847338f2acc2c7b834141 for pr-71393
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F02alexander%2Fmaze-solver" "/workspace/builds/worker-2/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/02alexander/maze-solver on toolchain 45d050cde277b22a755847338f2acc2c7b834141
[INFO] running `"/workspace/cargo-home/bin/cargo" "+45d050cde277b22a755847338f2acc2c7b834141" "read-manifest" "--manifest-path" "Cargo.toml"`
[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-2/source/Cargo.toml
[INFO] crate git repo https://github.com/02alexander/maze-solver already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+45d050cde277b22a755847338f2acc2c7b834141" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+45d050cde277b22a755847338f2acc2c7b834141" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] d69c01b3a8f22c57f66d6e5dfeaed6b0a38db1dc1d716a36cb2811d7ccd8d238
[INFO] running `"docker" "start" "-a" "d69c01b3a8f22c57f66d6e5dfeaed6b0a38db1dc1d716a36cb2811d7ccd8d238"`
[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] [stderr] warning: unused imports: `read`, `write`
[INFO] [stderr]  --> src/main.rs:3:16
[INFO] [stderr]   |
[INFO] [stderr] 3 | use imagefmt::{read, write, ColFmt, ColType};
[INFO] [stderr]   |                ^^^^  ^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::mem::drop`
[INFO] [stderr]  --> src/tree.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::mem::drop;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `Node`
[INFO] [stderr]  --> src/path_to_end.rs:3:35
[INFO] [stderr]   |
[INFO] [stderr] 3 | use super::tree::{QuaternaryTree, Node, Link};
[INFO] [stderr]   |                                   ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/tree.rs:41:8
[INFO] [stderr]    |
[INFO] [stderr] 41 |             let mut cur = &mut *next.take().unwrap();
[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: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/main.rs:20:2
[INFO] [stderr]    |
[INFO] [stderr] 20 |     imagefmt::write("out.bmp", maze.width, maze.height, ColFmt::RGB, &pixels, ColType::Auto);
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `read`, `write`
[INFO] [stderr]  --> src/main.rs:3:16
[INFO] [stderr]   |
[INFO] [stderr] 3 | use imagefmt::{read, write, ColFmt, ColType};
[INFO] [stderr]   |                ^^^^  ^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::mem::drop`
[INFO] [stderr]  --> src/tree.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::mem::drop;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 5 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/tree.rs:41:8
[INFO] [stderr]    |
[INFO] [stderr] 41 |             let mut cur = &mut *next.take().unwrap();
[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: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/main.rs:20:2
[INFO] [stderr]    |
[INFO] [stderr] 20 |     imagefmt::write("out.bmp", maze.width, maze.height, ColFmt::RGB, &pixels, ColType::Auto);
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: 4 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 7.33s
[INFO] running `"docker" "inspect" "d69c01b3a8f22c57f66d6e5dfeaed6b0a38db1dc1d716a36cb2811d7ccd8d238"`
[INFO] running `"docker" "rm" "-f" "d69c01b3a8f22c57f66d6e5dfeaed6b0a38db1dc1d716a36cb2811d7ccd8d238"`
[INFO] [stdout] d69c01b3a8f22c57f66d6e5dfeaed6b0a38db1dc1d716a36cb2811d7ccd8d238