[INFO] updating cached repository https://github.com/zlmisme/skiplist
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/mnt/big/crater/work/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] bbbf7be8190c1fc211fbf3f484a393c2466fa826
[INFO] checking zlmisme/skiplist against master#c9edc02e8320a9e5799d185910ece7d491f524e6 for pr-64398
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzlmisme%2Fskiplist" "work/builds/worker-6/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/zlmisme/skiplist on toolchain c9edc02e8320a9e5799d185910ece7d491f524e6-alt
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/zlmisme/skiplist
[INFO] finished tweaking git repo https://github.com/zlmisme/skiplist
[INFO] tweaked toml for git repo https://github.com/zlmisme/skiplist written to work/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/zlmisme/skiplist already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/mnt/big/crater/work/builds/worker-6/source:/opt/rustwide/workdir:ro,Z" "-v" "/mnt/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-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" "/opt/rustwide/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 6cac90fdc4b3abc775c60b534a6646bf0ceec67b98fb71925637f79b1ce20efc
[INFO] running `"docker" "start" "-a" "6cac90fdc4b3abc775c60b534a6646bf0ceec67b98fb71925637f79b1ce20efc"`
[INFO] [stderr]    Compiling autocfg v0.1.6
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking time v0.1.42
[INFO] [stderr]    Compiling num-traits v0.2.8
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stderr]     Checking rand v0.3.23
[INFO] [stderr]     Checking chrono v0.4.8
[INFO] [stderr]     Checking skiplist v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]  --> src/linked_list/mod.rs:8:5
[INFO] [stderr]   |
[INFO] [stderr] 8 |     pub fn new(elm: T) -> Self {
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `set_next`
[INFO] [stderr]   --> src/linked_list/mod.rs:12:5
[INFO] [stderr]    |
[INFO] [stderr] 12 |     pub fn set_next(&mut self, element: T) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `get_last`
[INFO] [stderr]   --> src/linked_list/mod.rs:16:5
[INFO] [stderr]    |
[INFO] [stderr] 16 |     fn get_last(&mut self) -> &mut Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `set_next`
[INFO] [stderr]   --> src/linked_list/mod.rs:31:5
[INFO] [stderr]    |
[INFO] [stderr] 31 |     pub fn set_next(&mut self, element: T) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]  --> src/linked_list/mod.rs:8:5
[INFO] [stderr]   |
[INFO] [stderr] 8 |     pub fn new(elm: T) -> Self {
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `set_next`
[INFO] [stderr]   --> src/linked_list/mod.rs:12:5
[INFO] [stderr]    |
[INFO] [stderr] 12 |     pub fn set_next(&mut self, element: T) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `get_last`
[INFO] [stderr]   --> src/linked_list/mod.rs:16:5
[INFO] [stderr]    |
[INFO] [stderr] 16 |     fn get_last(&mut self) -> &mut Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `set_next`
[INFO] [stderr]   --> src/linked_list/mod.rs:31:5
[INFO] [stderr]    |
[INFO] [stderr] 31 |     pub fn set_next(&mut self, element: T) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `print`
[INFO] [stderr]    --> src/main.rs:105:5
[INFO] [stderr]     |
[INFO] [stderr] 105 |     pub fn print(&self) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `print`
[INFO] [stderr]    --> src/main.rs:105:5
[INFO] [stderr]     |
[INFO] [stderr] 105 |     pub fn print(&self) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 10.10s
[INFO] running `"docker" "inspect" "6cac90fdc4b3abc775c60b534a6646bf0ceec67b98fb71925637f79b1ce20efc"`
[INFO] running `"docker" "rm" "-f" "6cac90fdc4b3abc775c60b534a6646bf0ceec67b98fb71925637f79b1ce20efc"`
[INFO] [stdout] 6cac90fdc4b3abc775c60b534a6646bf0ceec67b98fb71925637f79b1ce20efc