[INFO] fetching crate skiplist-rs 0.1.4...
[INFO] checking skiplist-rs-0.1.4 against master#a5f164faad4a2fed606b8160fd7ecd2d5cbba381 for pr-84920
[INFO] extracting crate skiplist-rs 0.1.4 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate skiplist-rs 0.1.4 on toolchain a5f164faad4a2fed606b8160fd7ecd2d5cbba381
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a5f164faad4a2fed606b8160fd7ecd2d5cbba381" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate skiplist-rs 0.1.4
[INFO] finished tweaking crates.io crate skiplist-rs 0.1.4
[INFO] tweaked toml for crates.io crate skiplist-rs 0.1.4 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a5f164faad4a2fed606b8160fd7ecd2d5cbba381" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a5f164faad4a2fed606b8160fd7ecd2d5cbba381" "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" "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" "+a5f164faad4a2fed606b8160fd7ecd2d5cbba381" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a336d0c324d50542e44b534251f1aca989a66db98adfbe6ed00e62d241de8660
[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" "a336d0c324d50542e44b534251f1aca989a66db98adfbe6ed00e62d241de8660", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a336d0c324d50542e44b534251f1aca989a66db98adfbe6ed00e62d241de8660", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a336d0c324d50542e44b534251f1aca989a66db98adfbe6ed00e62d241de8660", kill_on_drop: false }`
[INFO] [stdout] a336d0c324d50542e44b534251f1aca989a66db98adfbe6ed00e62d241de8660
[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" "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" "+a5f164faad4a2fed606b8160fd7ecd2d5cbba381" "check" "--frozen" "--all" "--all-targets" "--message-format=json", 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] 3c91cc979163bc20067e4d277721840bcb12ef99909042c86a7be61e3d4e8a1c
[INFO] running `Command { std: "docker" "start" "-a" "3c91cc979163bc20067e4d277721840bcb12ef99909042c86a7be61e3d4e8a1c", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.94
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]     Checking getrandom v0.1.16
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking skiplist-rs v0.1.4 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::cmp::Ordering`
[INFO] [stdout]  --> src/lib.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::cmp::Ordering;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::LinkedList`
[INFO] [stdout]  --> src/lib.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::collections::LinkedList;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::ops::FnMut`
[INFO] [stdout]  --> src/lib.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::ops::FnMut;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::ptr::NonNull`
[INFO] [stdout]  --> src/lib.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 | use std::ptr::NonNull;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::HashMap`
[INFO] [stdout]    --> src/lib.rs:406:9
[INFO] [stdout]     |
[INFO] [stdout] 406 |     use std::collections::HashMap;
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cmp::Ordering`
[INFO] [stdout]  --> src/lib.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::cmp::Ordering;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cmp::PartialEq`
[INFO] [stdout]  --> src/lib.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::cmp::PartialEq;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::LinkedList`
[INFO] [stdout]  --> src/lib.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::collections::LinkedList;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::ops::FnMut`
[INFO] [stdout]  --> src/lib.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::ops::FnMut;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::ptr::NonNull`
[INFO] [stdout]  --> src/lib.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 | use std::ptr::NonNull;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `core::fmt`
[INFO] [stdout]   --> src/lib.rs:10:5
[INFO] [stdout]    |
[INFO] [stdout] 10 | use core::fmt;
[INFO] [stdout]    |     ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lib.rs:33:21
[INFO] [stdout]    |
[INFO] [stdout] 33 |         if let Some(mut t) = self.find(&key) {
[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: variable does not need to be mutable
[INFO] [stdout]   --> src/lib.rs:33:21
[INFO] [stdout]    |
[INFO] [stdout] 33 |         if let Some(mut t) = self.find(&key) {
[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: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 6.36s
[INFO] running `Command { std: "docker" "inspect" "3c91cc979163bc20067e4d277721840bcb12ef99909042c86a7be61e3d4e8a1c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3c91cc979163bc20067e4d277721840bcb12ef99909042c86a7be61e3d4e8a1c", kill_on_drop: false }`
[INFO] [stdout] 3c91cc979163bc20067e4d277721840bcb12ef99909042c86a7be61e3d4e8a1c