[INFO] updating cached repository https://github.com/jaredonline/rust-skip-list
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 31e304a8a8ec2c917e47b7c4cfc3a84fe46768ea
[INFO] checking jaredonline/rust-skip-list against try#c8bdaa84ec1b37f18f30375e196a65b7602f3790 for pr-73345
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjaredonline%2Frust-skip-list" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jaredonline/rust-skip-list on toolchain c8bdaa84ec1b37f18f30375e196a65b7602f3790
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c8bdaa84ec1b37f18f30375e196a65b7602f3790" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/jaredonline/rust-skip-list
[INFO] finished tweaking git repo https://github.com/jaredonline/rust-skip-list
[INFO] tweaked toml for git repo https://github.com/jaredonline/rust-skip-list written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/jaredonline/rust-skip-list already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c8bdaa84ec1b37f18f30375e196a65b7602f3790" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr] error: the lock file /workspace/builds/worker-7/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] [stderr] If you want to try to generate the lock file without accessing the network, use the --offline flag.
[INFO] the lockfile is outdated, regenerating it
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c8bdaa84ec1b37f18f30375e196a65b7602f3790" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c8bdaa84ec1b37f18f30375e196a65b7602f3790" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:6c9ffe128752d56c8d75334ed354142a5229917ed99767f56566dd8e857ad726" "/opt/rustwide/cargo-home/bin/cargo" "+c8bdaa84ec1b37f18f30375e196a65b7602f3790" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c23b2136a61c37df37900792c8f4a5e540e1bb717764f5125182e94be08138b8
[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" "c23b2136a61c37df37900792c8f4a5e540e1bb717764f5125182e94be08138b8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c23b2136a61c37df37900792c8f4a5e540e1bb717764f5125182e94be08138b8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c23b2136a61c37df37900792c8f4a5e540e1bb717764f5125182e94be08138b8", kill_on_drop: false }`
[INFO] [stdout] c23b2136a61c37df37900792c8f4a5e540e1bb717764f5125182e94be08138b8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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@sha256:6c9ffe128752d56c8d75334ed354142a5229917ed99767f56566dd8e857ad726" "/opt/rustwide/cargo-home/bin/cargo" "+c8bdaa84ec1b37f18f30375e196a65b7602f3790" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 417a1c41d108f64a6c0770086a2d90ecba322f9958fae42502be7a5fb1cd614b
[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" "417a1c41d108f64a6c0770086a2d90ecba322f9958fae42502be7a5fb1cd614b", kill_on_drop: false }`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling libc v0.2.71
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking rand v0.3.23
[INFO] [stderr]     Checking linked-list v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:235:14
[INFO] [stdout]     |
[INFO] [stdout] 235 |     for i in (0 .. 10) {
[INFO] [stdout]     |              ^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:245:14
[INFO] [stdout]     |
[INFO] [stdout] 245 |     for i in (0 .. 10) {
[INFO] [stdout]     |              ^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:259:14
[INFO] [stdout]     |
[INFO] [stdout] 259 |     for i in (0 .. 10) {
[INFO] [stdout]     |              ^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:265:14
[INFO] [stdout]     |
[INFO] [stdout] 265 |     for i in (0 .. 100) {
[INFO] [stdout]     |              ^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:301:18
[INFO] [stdout]     |
[INFO] [stdout] 301 |         for i in (0 .. 100) {
[INFO] [stdout]     |                  ^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:305:18
[INFO] [stdout]     |
[INFO] [stdout] 305 |         for i in (0 .. 100) {
[INFO] [stdout]     |                  ^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:313:18
[INFO] [stdout]     |
[INFO] [stdout] 313 |         for i in (0 .. 100) {
[INFO] [stdout]     |                  ^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:328:18
[INFO] [stdout]     |
[INFO] [stdout] 328 |         for i in (1 .. 1000) {
[INFO] [stdout]     |                  ^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> src/main.rs:344:22
[INFO] [stdout]     |
[INFO] [stdout] 344 |             for i in (0 .. 7) {
[INFO] [stdout]     |                      ^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `get_node_count`
[INFO] [stdout]   --> src/main.rs:97:4
[INFO] [stdout]    |
[INFO] [stdout] 97 | fn get_node_count() -> usize {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.40s
[INFO] running `Command { std: "docker" "inspect" "417a1c41d108f64a6c0770086a2d90ecba322f9958fae42502be7a5fb1cd614b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "417a1c41d108f64a6c0770086a2d90ecba322f9958fae42502be7a5fb1cd614b", kill_on_drop: false }`
[INFO] [stdout] 417a1c41d108f64a6c0770086a2d90ecba322f9958fae42502be7a5fb1cd614b