[INFO] cloning repository https://github.com/tmazhuan/datastructures_algorithms
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tmazhuan/datastructures_algorithms" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftmazhuan%2Fdatastructures_algorithms", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftmazhuan%2Fdatastructures_algorithms'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 1c4140b332eed402795fdca87d585183b8bd6de6
[INFO] checking tmazhuan/datastructures_algorithms against try#4a04890980766cc79878135f5ade8c0c4321e943 for pr-65819
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftmazhuan%2Fdatastructures_algorithms" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tmazhuan/datastructures_algorithms on toolchain 4a04890980766cc79878135f5ade8c0c4321e943
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4a04890980766cc79878135f5ade8c0c4321e943" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/tmazhuan/datastructures_algorithms
[INFO] finished tweaking git repo https://github.com/tmazhuan/datastructures_algorithms
[INFO] tweaked toml for git repo https://github.com/tmazhuan/datastructures_algorithms written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/tmazhuan/datastructures_algorithms already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4a04890980766cc79878135f5ade8c0c4321e943" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/jobserver:/tmp/crater-runner-fifo:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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:c46a2d1a26fb48b37929c74ca49dd9409f2375a0a3bdb8fe07617f3ffccaa889" "/opt/rustwide/cargo-home/bin/cargo" "+4a04890980766cc79878135f5ade8c0c4321e943" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d9ebfa8786f596bb88dcfa76bff24c1b65fa27ea6e72db2ffbf92dbf4fffd3a4
[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" "d9ebfa8786f596bb88dcfa76bff24c1b65fa27ea6e72db2ffbf92dbf4fffd3a4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d9ebfa8786f596bb88dcfa76bff24c1b65fa27ea6e72db2ffbf92dbf4fffd3a4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d9ebfa8786f596bb88dcfa76bff24c1b65fa27ea6e72db2ffbf92dbf4fffd3a4", kill_on_drop: false }`
[INFO] [stdout] d9ebfa8786f596bb88dcfa76bff24c1b65fa27ea6e72db2ffbf92dbf4fffd3a4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/jobserver:/tmp/crater-runner-fifo:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "RUSTUP_TOOLCHAIN=4a04890980766cc79878135f5ade8c0c4321e943" "-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:c46a2d1a26fb48b37929c74ca49dd9409f2375a0a3bdb8fe07617f3ffccaa889" "/tmp/crater-runner-fifo/jobserver-crater-fwd" "/opt/rustwide/cargo-home/bin/cargo" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 50eca8d5b9cb06bb88f5a847cb08a5ac7da41bcc82cdeab1f4b6caee5fd01295
[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" "50eca8d5b9cb06bb88f5a847cb08a5ac7da41bcc82cdeab1f4b6caee5fd01295", kill_on_drop: false }`
[INFO] [stderr]     Checking fifo v0.1.0 (/opt/rustwide/workdir/fifo)
[INFO] [stderr]     Checking lists v0.1.0 (/opt/rustwide/workdir/lists)
[INFO] [stderr]     Checking lifo v0.1.0 (/opt/rustwide/workdir/lifo)
[INFO] [stdout] warning: field is never read: `head`
[INFO] [stdout]   --> lifo/src/lib.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |         head: Link<T>,
[INFO] [stdout]    |         ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `head`
[INFO] [stdout]   --> lifo/src/lib.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |         head: Link<T>,
[INFO] [stdout]    |         ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking tester v0.1.0 (/opt/rustwide/workdir/tester)
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.84s
[INFO] running `Command { std: "docker" "inspect" "50eca8d5b9cb06bb88f5a847cb08a5ac7da41bcc82cdeab1f4b6caee5fd01295", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "50eca8d5b9cb06bb88f5a847cb08a5ac7da41bcc82cdeab1f4b6caee5fd01295", kill_on_drop: false }`
[INFO] [stdout] 50eca8d5b9cb06bb88f5a847cb08a5ac7da41bcc82cdeab1f4b6caee5fd01295