[INFO] cloning repository https://github.com/tworec/mandelbrot
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tworec/mandelbrot" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftworec%2Fmandelbrot"`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftworec%2Fmandelbrot'...
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] d5107e49abb76e7ca1bc0cb39540e967de7f26f2
[INFO] checking tworec/mandelbrot against master#b61e69433951e31f7bd746e22f516a48ad41623b for prs-64470-and-65389
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftworec%2Fmandelbrot" "/workspace/builds/worker-4/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tworec/mandelbrot on toolchain b61e69433951e31f7bd746e22f516a48ad41623b
[INFO] running `"/workspace/cargo-home/bin/cargo" "+b61e69433951e31f7bd746e22f516a48ad41623b" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/tworec/mandelbrot
[INFO] finished tweaking git repo https://github.com/tworec/mandelbrot
[INFO] tweaked toml for git repo https://github.com/tworec/mandelbrot written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/tworec/mandelbrot already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+b61e69433951e31f7bd746e22f516a48ad41623b" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+b61e69433951e31f7bd746e22f516a48ad41623b" "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] 393a44f65d26eec9d850ca332631be19b75d98e4ff275a56731444e6ee05f222
[INFO] running `"docker" "start" "-a" "393a44f65d26eec9d850ca332631be19b75d98e4ff275a56731444e6ee05f222"`
[INFO] [stderr]    Compiling libc v0.2.61
[INFO] [stderr]    Compiling num-complex v0.2.3
[INFO] [stderr]     Checking atty v0.2.13
[INFO] [stderr]     Checking backtrace-sys v0.1.31
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking backtrace v0.3.35
[INFO] [stderr]     Checking failure v0.1.5
[INFO] [stderr]     Checking structopt v0.2.18
[INFO] [stderr]     Checking mandelbrot v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused import: `ErrorKind`
[INFO] [stderr]  --> src/main.rs:3:26
[INFO] [stderr]   |
[INFO] [stderr] 3 | use std::io::{BufWriter, ErrorKind};
[INFO] [stderr]   |                          ^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `ErrorKind`
[INFO] [stderr]  --> src/main.rs:3:26
[INFO] [stderr]   |
[INFO] [stderr] 3 | use std::io::{BufWriter, ErrorKind};
[INFO] [stderr]   |                          ^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `display`
[INFO] [stderr]    --> src/main.rs:139:9
[INFO] [stderr]     |
[INFO] [stderr] 139 |     let display = path.display();
[INFO] [stderr]     |         ^^^^^^^ help: consider prefixing with an underscore: `_display`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `display`
[INFO] [stderr]    --> src/main.rs:139:9
[INFO] [stderr]     |
[INFO] [stderr] 139 |     let display = path.display();
[INFO] [stderr]     |         ^^^^^^^ help: consider prefixing with an underscore: `_display`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]    --> src/main.rs:102:5
[INFO] [stderr]     |
[INFO] [stderr] 102 |     save_file(&params.output, &data, width, height);
[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 `std::result::Result` that must be used
[INFO] [stderr]    --> src/main.rs:181:5
[INFO] [stderr]     |
[INFO] [stderr] 181 |     save_file(output_path.to_str().unwrap(), &data, opt.width, opt.height);
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]    --> src/main.rs:102:5
[INFO] [stderr]     |
[INFO] [stderr] 102 |     save_file(&params.output, &data, width, height);
[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 `std::result::Result` that must be used
[INFO] [stderr]    --> src/main.rs:181:5
[INFO] [stderr]     |
[INFO] [stderr] 181 |     save_file(output_path.to_str().unwrap(), &data, opt.width, opt.height);
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 17.99s
[INFO] running `"docker" "inspect" "393a44f65d26eec9d850ca332631be19b75d98e4ff275a56731444e6ee05f222"`
[INFO] running `"docker" "rm" "-f" "393a44f65d26eec9d850ca332631be19b75d98e4ff275a56731444e6ee05f222"`
[INFO] [stdout] 393a44f65d26eec9d850ca332631be19b75d98e4ff275a56731444e6ee05f222