[INFO] cloning repository https://github.com/deavid/crappylinkedlists
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/deavid/crappylinkedlists" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdeavid%2Fcrappylinkedlists", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdeavid%2Fcrappylinkedlists'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] dfdadb1df2118974621525dfc64e31efcb567ebf
[INFO] checking deavid/crappylinkedlists against master#836c31742687ba4e2f857b5b698e1e9e6b67619c for pr-81789
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdeavid%2Fcrappylinkedlists" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/deavid/crappylinkedlists on toolchain 836c31742687ba4e2f857b5b698e1e9e6b67619c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+836c31742687ba4e2f857b5b698e1e9e6b67619c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/deavid/crappylinkedlists
[INFO] finished tweaking git repo https://github.com/deavid/crappylinkedlists
[INFO] tweaked toml for git repo https://github.com/deavid/crappylinkedlists written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/deavid/crappylinkedlists already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+836c31742687ba4e2f857b5b698e1e9e6b67619c" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+836c31742687ba4e2f857b5b698e1e9e6b67619c" "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] d3f3602029614a733dc82f2a1cab49e5d2c73bc2da1825af7f644ed4310610c7
[INFO] running `Command { std: "docker" "start" "-a" "d3f3602029614a733dc82f2a1cab49e5d2c73bc2da1825af7f644ed4310610c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d3f3602029614a733dc82f2a1cab49e5d2c73bc2da1825af7f644ed4310610c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d3f3602029614a733dc82f2a1cab49e5d2c73bc2da1825af7f644ed4310610c7", kill_on_drop: false }`
[INFO] [stdout] d3f3602029614a733dc82f2a1cab49e5d2c73bc2da1825af7f644ed4310610c7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+836c31742687ba4e2f857b5b698e1e9e6b67619c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e5e71ad40357187743b90577e0cfbd20bcfe4adbddf5c692cbaa22f7a9bcd869
[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" "e5e71ad40357187743b90577e0cfbd20bcfe4adbddf5c692cbaa22f7a9bcd869", kill_on_drop: false }`
[INFO] [stderr]    Compiling version_check v0.9.1
[INFO] [stderr]     Checking bencher v0.1.5
[INFO] [stderr]    Compiling backtrace-sys v0.1.36
[INFO] [stderr]    Compiling cpuprofiler v0.0.4
[INFO] [stderr]    Compiling error-chain v0.12.2
[INFO] [stderr]     Checking backtrace v0.3.46
[INFO] [stderr]     Checking crappylinkedlists v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/linked5/mod.rs:86:13
[INFO] [stdout]    |
[INFO] [stdout] 86 |         let mut nodes: Vec<Rc<RefCell<Node>>> = v
[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] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/linked5/mod.rs:86:13
[INFO] [stdout]    |
[INFO] [stdout] 86 |         let mut nodes: Vec<Rc<RefCell<Node>>> = v
[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 7.50s
[INFO] running `Command { std: "docker" "inspect" "e5e71ad40357187743b90577e0cfbd20bcfe4adbddf5c692cbaa22f7a9bcd869", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e5e71ad40357187743b90577e0cfbd20bcfe4adbddf5c692cbaa22f7a9bcd869", kill_on_drop: false }`
[INFO] [stdout] e5e71ad40357187743b90577e0cfbd20bcfe4adbddf5c692cbaa22f7a9bcd869