[INFO] cloning repository https://github.com/RetroMeras/sudoku_solver
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/RetroMeras/sudoku_solver" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FRetroMeras%2Fsudoku_solver", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FRetroMeras%2Fsudoku_solver'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 82de8e51b4e3293b21f747a76343699ac11249da
[INFO] checking RetroMeras/sudoku_solver/82de8e51b4e3293b21f747a76343699ac11249da against master#ab869e094a907cc5d19b4080f22eccaf347f1f95 for pr-129604
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FRetroMeras%2Fsudoku_solver" "/workspace/builds/worker-5-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/RetroMeras/sudoku_solver on toolchain ab869e094a907cc5d19b4080f22eccaf347f1f95
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/RetroMeras/sudoku_solver
[INFO] finished tweaking git repo https://github.com/RetroMeras/sudoku_solver
[INFO] tweaked toml for git repo https://github.com/RetroMeras/sudoku_solver written to /workspace/builds/worker-5-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/RetroMeras/sudoku_solver 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" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded dancing-links v0.2.0
[INFO] [stderr]   Downloaded syn v1.0.77
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5fb23f12a25d280f07ce35b2e50b79269bbf55caa9f3baae6b5cd62855b0ffcb
[INFO] running `Command { std: "docker" "start" "-a" "5fb23f12a25d280f07ce35b2e50b79269bbf55caa9f3baae6b5cd62855b0ffcb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5fb23f12a25d280f07ce35b2e50b79269bbf55caa9f3baae6b5cd62855b0ffcb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5fb23f12a25d280f07ce35b2e50b79269bbf55caa9f3baae6b5cd62855b0ffcb", kill_on_drop: false }`
[INFO] [stdout] 5fb23f12a25d280f07ce35b2e50b79269bbf55caa9f3baae6b5cd62855b0ffcb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8196d08293287bba57880d05a5ae04ef89a15d22d9fa84d31cc4dde5b75ceed9
[INFO] running `Command { std: "docker" "start" "-a" "8196d08293287bba57880d05a5ae04ef89a15d22d9fa84d31cc4dde5b75ceed9", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.77
[INFO] [stderr]    Compiling serde_json v1.0.68
[INFO] [stderr]     Checking bumpalo v3.7.1
[INFO] [stderr]     Checking itoa v0.4.8
[INFO] [stderr]     Checking dancing-links v0.2.0
[INFO] [stderr]    Compiling serde_derive v1.0.130
[INFO] [stderr]     Checking serde v1.0.130
[INFO] [stderr]     Checking sudoku_solver v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: for loop over an `Option`. This is more readably written as an `if let` statement
[INFO] [stdout]   --> src/main.rs:31:20
[INFO] [stdout]    |
[INFO] [stdout] 31 |           for s in sols {
[INFO] [stdout]    |                    ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(for_loops_over_fallibles)]` on by default
[INFO] [stdout] help: to check pattern in a loop use `while let`
[INFO] [stdout]    |
[INFO] [stdout] 31 |           while let Some(s) = sols {
[INFO] [stdout]    |           ~~~~~~~~~~~~~~~ ~~~
[INFO] [stdout] help: consider using `if let` to clear intent
[INFO] [stdout]    |
[INFO] [stdout] 31 |           if let Some(s) = sols {
[INFO] [stdout]    |           ~~~~~~~~~~~~ ~~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: for loop over an `Option`. This is more readably written as an `if let` statement
[INFO] [stdout]   --> src/main.rs:31:20
[INFO] [stdout]    |
[INFO] [stdout] 31 |           for s in sols {
[INFO] [stdout]    |                    ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(for_loops_over_fallibles)]` on by default
[INFO] [stdout] help: to check pattern in a loop use `while let`
[INFO] [stdout]    |
[INFO] [stdout] 31 |           while let Some(s) = sols {
[INFO] [stdout]    |           ~~~~~~~~~~~~~~~ ~~~
[INFO] [stdout] help: consider using `if let` to clear intent
[INFO] [stdout]    |
[INFO] [stdout] 31 |           if let Some(s) = sols {
[INFO] [stdout]    |           ~~~~~~~~~~~~ ~~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 11.00s
[INFO] running `Command { std: "docker" "inspect" "8196d08293287bba57880d05a5ae04ef89a15d22d9fa84d31cc4dde5b75ceed9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8196d08293287bba57880d05a5ae04ef89a15d22d9fa84d31cc4dde5b75ceed9", kill_on_drop: false }`
[INFO] [stdout] 8196d08293287bba57880d05a5ae04ef89a15d22d9fa84d31cc4dde5b75ceed9