[INFO] updating cached repository https://github.com/llwwns/pairing_heap
[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] b8f1c8ff87c95c26a0d04a2ed75c5b818fb34881
[INFO] checking llwwns/pairing_heap against master#e1beee4992ad4b235fc700bf7af1ee86f894ea53 for pr-74130
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fllwwns%2Fpairing_heap" "/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/llwwns/pairing_heap on toolchain e1beee4992ad4b235fc700bf7af1ee86f894ea53
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+e1beee4992ad4b235fc700bf7af1ee86f894ea53" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/llwwns/pairing_heap
[INFO] finished tweaking git repo https://github.com/llwwns/pairing_heap
[INFO] tweaked toml for git repo https://github.com/llwwns/pairing_heap written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/llwwns/pairing_heap already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+e1beee4992ad4b235fc700bf7af1ee86f894ea53" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-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" "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@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+e1beee4992ad4b235fc700bf7af1ee86f894ea53" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] d5fcf45cebb5900487a93a76c84445cf7ea11e5f770ce706921b1257dd2c1163
[INFO] running `Command { std: "docker" "start" "-a" "d5fcf45cebb5900487a93a76c84445cf7ea11e5f770ce706921b1257dd2c1163", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d5fcf45cebb5900487a93a76c84445cf7ea11e5f770ce706921b1257dd2c1163", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d5fcf45cebb5900487a93a76c84445cf7ea11e5f770ce706921b1257dd2c1163", kill_on_drop: false }`
[INFO] [stdout] d5fcf45cebb5900487a93a76c84445cf7ea11e5f770ce706921b1257dd2c1163
[INFO] running `Command { std: "docker" "create" "-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" "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@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+e1beee4992ad4b235fc700bf7af1ee86f894ea53" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bf4298e208493ca3c87b3e62dfcd9257d43df0de97f5ea85c067e7cea71c9efe
[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" "bf4298e208493ca3c87b3e62dfcd9257d43df0de97f5ea85c067e7cea71c9efe", kill_on_drop: false }`
[INFO] [stderr]     Checking pairing_heap v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/forward_list.rs:291:7
[INFO] [stdout]     |
[INFO] [stdout] 291 |   let mut x: Vec<_> = a.into_iter().collect();
[INFO] [stdout]     |       ----^
[INFO] [stdout]     |       |
[INFO] [stdout]     |       help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.31s
[INFO] running `Command { std: "docker" "inspect" "bf4298e208493ca3c87b3e62dfcd9257d43df0de97f5ea85c067e7cea71c9efe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bf4298e208493ca3c87b3e62dfcd9257d43df0de97f5ea85c067e7cea71c9efe", kill_on_drop: false }`
[INFO] [stdout] bf4298e208493ca3c87b3e62dfcd9257d43df0de97f5ea85c067e7cea71c9efe