[INFO] cloning repository https://github.com/aacunningham/sudoku_ai_rust
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/aacunningham/sudoku_ai_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Faacunningham%2Fsudoku_ai_rust"`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Faacunningham%2Fsudoku_ai_rust'...
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] d5b69a2046169ce2c76b985809042171f5e69fb5
[INFO] checking aacunningham/sudoku_ai_rust against master#45d050cde277b22a755847338f2acc2c7b834141 for pr-71393
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Faacunningham%2Fsudoku_ai_rust" "/workspace/builds/worker-11/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-11/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/aacunningham/sudoku_ai_rust 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/aacunningham/sudoku_ai_rust
[INFO] finished tweaking git repo https://github.com/aacunningham/sudoku_ai_rust
[INFO] tweaked toml for git repo https://github.com/aacunningham/sudoku_ai_rust written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate git repo https://github.com/aacunningham/sudoku_ai_rust 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-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] bd1cfc7500098eaefd54829c01986a665881b0b120c3343cbf16624ba792a98c
[INFO] running `"docker" "start" "-a" "bd1cfc7500098eaefd54829c01986a665881b0b120c3343cbf16624ba792a98c"`
[INFO] [stderr]     Checking sudoku_ai v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: the feature `iterator_step_by` has been stable since 1.28.0 and no longer requires an attribute to enable
[INFO] [stderr]  --> src/lib.rs:1:12
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(iterator_step_by)]
[INFO] [stderr]   |            ^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(stable_features)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr] warning: the feature `iterator_step_by` has been stable since 1.28.0 and no longer requires an attribute to enable
[INFO] [stderr]  --> src/lib.rs:1:12
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(iterator_step_by)]
[INFO] [stderr]   |            ^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(stable_features)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.02s
[INFO] running `"docker" "inspect" "bd1cfc7500098eaefd54829c01986a665881b0b120c3343cbf16624ba792a98c"`
[INFO] running `"docker" "rm" "-f" "bd1cfc7500098eaefd54829c01986a665881b0b120c3343cbf16624ba792a98c"`
[INFO] [stdout] bd1cfc7500098eaefd54829c01986a665881b0b120c3343cbf16624ba792a98c