[INFO] cloning repository https://github.com/howeih/Day-41-Union-Find
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/howeih/Day-41-Union-Find" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhoweih%2FDay-41-Union-Find", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhoweih%2FDay-41-Union-Find'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 32bc36cc71e78ad0217c3dc428395f49b9f0fe15
[INFO] checking howeih/Day-41-Union-Find against master#5e3f1b148db5bfa27fee52464ae1f5d34c49d77b for pr-75502
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhoweih%2FDay-41-Union-Find" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/howeih/Day-41-Union-Find on toolchain 5e3f1b148db5bfa27fee52464ae1f5d34c49d77b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/howeih/Day-41-Union-Find
[INFO] finished tweaking git repo https://github.com/howeih/Day-41-Union-Find
[INFO] tweaked toml for git repo https://github.com/howeih/Day-41-Union-Find written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/howeih/Day-41-Union-Find already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "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" "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" "rustops/crates-build-env@sha256:e18d859f9e32a1da89bc7b2d7d51e13b57342044d1295d9fc0dd0068c58eb3d1" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5fedf1b1ba8fdce4a3d9afacfff9ee8e186f0d8f0a6e740341a7a04d6506b7bc
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "5fedf1b1ba8fdce4a3d9afacfff9ee8e186f0d8f0a6e740341a7a04d6506b7bc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5fedf1b1ba8fdce4a3d9afacfff9ee8e186f0d8f0a6e740341a7a04d6506b7bc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5fedf1b1ba8fdce4a3d9afacfff9ee8e186f0d8f0a6e740341a7a04d6506b7bc", kill_on_drop: false }`
[INFO] [stdout] 5fedf1b1ba8fdce4a3d9afacfff9ee8e186f0d8f0a6e740341a7a04d6506b7bc
[INFO] running `Command { std: "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" "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" "rustops/crates-build-env@sha256:e18d859f9e32a1da89bc7b2d7d51e13b57342044d1295d9fc0dd0068c58eb3d1" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8cee40038b0bca86ca875fecb03bb26e9fb56bda75324f97fab2da80a4351eef
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "8cee40038b0bca86ca875fecb03bb26e9fb56bda75324f97fab2da80a4351eef", kill_on_drop: false }`
[INFO] [stderr]     Checking union_find v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::iter::Iterator`
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::iter::Iterator;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::iter::Iterator`
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::iter::Iterator;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[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 [unoptimized + debuginfo] target(s) in 0.13s
[INFO] running `Command { std: "docker" "inspect" "8cee40038b0bca86ca875fecb03bb26e9fb56bda75324f97fab2da80a4351eef", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8cee40038b0bca86ca875fecb03bb26e9fb56bda75324f97fab2da80a4351eef", kill_on_drop: false }`
[INFO] [stdout] 8cee40038b0bca86ca875fecb03bb26e9fb56bda75324f97fab2da80a4351eef