[INFO] updating cached repository https://github.com/jonstites/algorithms
[INFO] running `"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"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] c6aa15346e30e184f4abbc97963fd7333aa066e6
[INFO] testing jonstites/algorithms against 1.44.0 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjonstites%2Falgorithms" "/workspace/builds/worker-4/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jonstites/algorithms on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/jonstites/algorithms
[INFO] finished tweaking git repo https://github.com/jonstites/algorithms
[INFO] tweaked toml for git repo https://github.com/jonstites/algorithms written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/jonstites/algorithms already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-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" "+1.44.0" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 3d95fb04ac101a3de9a7d7897c7160d0bb7327249d6ed839bae888b74e96384b
[INFO] running `"docker" "start" "-a" "3d95fb04ac101a3de9a7d7897c7160d0bb7327249d6ed839bae888b74e96384b"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling clap v2.33.0
[INFO] [stderr]    Compiling algorithms v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused import: `std::iter`
[INFO] [stderr]    --> src/lib.rs:364:9
[INFO] [stderr]     |
[INFO] [stderr] 364 |     use std::iter;
[INFO] [stderr]     |         ^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `head`
[INFO] [stderr]    --> src/lib.rs:271:17
[INFO] [stderr]     |
[INFO] [stderr] 271 |             let head = match self.to_head() {
[INFO] [stderr]     |                 ^^^^ help: if this is intentional, prefix it with an underscore: `_head`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `nodes`
[INFO] [stderr]    --> src/data.rs:501:13
[INFO] [stderr]     |
[INFO] [stderr] 501 |             nodes: Vec<T>,
[INFO] [stderr]     |             ^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]    --> src/data.rs:681:13
[INFO] [stderr]     |
[INFO] [stderr] 681 |             pub fn new() -> Trie {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `contains`
[INFO] [stderr]    --> src/data.rs:688:13
[INFO] [stderr]     |
[INFO] [stderr] 688 |             pub fn contains(&self, t: &str) -> bool {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `contains_prefix`
[INFO] [stderr]    --> src/data.rs:696:13
[INFO] [stderr]     |
[INFO] [stderr] 696 |             pub fn contains_prefix(&self, t: &str) -> bool {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `child_matches`
[INFO] [stderr]    --> src/data.rs:700:13
[INFO] [stderr]     |
[INFO] [stderr] 700 |             fn child_matches(&self, t: &str) -> Option<&Trie> {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `add`
[INFO] [stderr]    --> src/data.rs:716:13
[INFO] [stderr]     |
[INFO] [stderr] 716 |             pub fn add(&mut self, values: &str) {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `add_chars`
[INFO] [stderr]    --> src/data.rs:721:13
[INFO] [stderr]     |
[INFO] [stderr] 721 |             fn add_chars(&mut self, values: &mut Chars) {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `add_char`
[INFO] [stderr]    --> src/data.rs:731:13
[INFO] [stderr]     |
[INFO] [stderr] 731 |             fn add_char(&mut self, value: char) -> usize {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `set_complete`
[INFO] [stderr]    --> src/data.rs:747:13
[INFO] [stderr]     |
[INFO] [stderr] 747 |             fn set_complete(&mut self) {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 11 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 16.23s
[INFO] running `"docker" "inspect" "3d95fb04ac101a3de9a7d7897c7160d0bb7327249d6ed839bae888b74e96384b"`
[INFO] running `"docker" "rm" "-f" "3d95fb04ac101a3de9a7d7897c7160d0bb7327249d6ed839bae888b74e96384b"`
[INFO] [stdout] 3d95fb04ac101a3de9a7d7897c7160d0bb7327249d6ed839bae888b74e96384b
[INFO] running `"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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-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" "+1.44.0" "test" "--frozen" "--no-run"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 28181f6eafc559c8418a3b7bd4c0d049af187614402284a68f34e37eb467ca7f
[INFO] running `"docker" "start" "-a" "28181f6eafc559c8418a3b7bd4c0d049af187614402284a68f34e37eb467ca7f"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling algorithms v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused import: `std::iter`
[INFO] [stderr]    --> src/lib.rs:364:9
[INFO] [stderr]     |
[INFO] [stderr] 364 |     use std::iter;
[INFO] [stderr]     |         ^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `head`
[INFO] [stderr]    --> src/lib.rs:271:17
[INFO] [stderr]     |
[INFO] [stderr] 271 |             let head = match self.to_head() {
[INFO] [stderr]     |                 ^^^^ help: if this is intentional, prefix it with an underscore: `_head`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `nodes`
[INFO] [stderr]    --> src/data.rs:501:13
[INFO] [stderr]     |
[INFO] [stderr] 501 |             nodes: Vec<T>,
[INFO] [stderr]     |             ^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]    --> src/data.rs:681:13
[INFO] [stderr]     |
[INFO] [stderr] 681 |             pub fn new() -> Trie {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `contains`
[INFO] [stderr]    --> src/data.rs:688:13
[INFO] [stderr]     |
[INFO] [stderr] 688 |             pub fn contains(&self, t: &str) -> bool {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `contains_prefix`
[INFO] [stderr]    --> src/data.rs:696:13
[INFO] [stderr]     |
[INFO] [stderr] 696 |             pub fn contains_prefix(&self, t: &str) -> bool {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `child_matches`
[INFO] [stderr]    --> src/data.rs:700:13
[INFO] [stderr]     |
[INFO] [stderr] 700 |             fn child_matches(&self, t: &str) -> Option<&Trie> {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `add`
[INFO] [stderr]    --> src/data.rs:716:13
[INFO] [stderr]     |
[INFO] [stderr] 716 |             pub fn add(&mut self, values: &str) {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `add_chars`
[INFO] [stderr]    --> src/data.rs:721:13
[INFO] [stderr]     |
[INFO] [stderr] 721 |             fn add_chars(&mut self, values: &mut Chars) {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `add_char`
[INFO] [stderr]    --> src/data.rs:731:13
[INFO] [stderr]     |
[INFO] [stderr] 731 |             fn add_char(&mut self, value: char) -> usize {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `set_complete`
[INFO] [stderr]    --> src/data.rs:747:13
[INFO] [stderr]     |
[INFO] [stderr] 747 |             fn set_complete(&mut self) {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 11 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::iter`
[INFO] [stderr]    --> src/lib.rs:364:9
[INFO] [stderr]     |
[INFO] [stderr] 364 |     use std::iter;
[INFO] [stderr]     |         ^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `head`
[INFO] [stderr]    --> src/lib.rs:271:17
[INFO] [stderr]     |
[INFO] [stderr] 271 |             let head = match self.to_head() {
[INFO] [stderr]     |                 ^^^^ help: if this is intentional, prefix it with an underscore: `_head`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `nodes`
[INFO] [stderr]    --> src/data.rs:501:13
[INFO] [stderr]     |
[INFO] [stderr] 501 |             nodes: Vec<T>,
[INFO] [stderr]     |             ^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]    --> src/lib.rs:346:13
[INFO] [stderr]     |
[INFO] [stderr] 346 |             graph.add_edge(a, b);
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]    --> src/lib.rs:351:13
[INFO] [stderr]     |
[INFO] [stderr] 351 |             graph.add_edge(c, d);
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]    --> src/lib.rs:352:13
[INFO] [stderr]     |
[INFO] [stderr] 352 |             graph.add_edge(d, c);
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: 6 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 4.45s
[INFO] running `"docker" "inspect" "28181f6eafc559c8418a3b7bd4c0d049af187614402284a68f34e37eb467ca7f"`
[INFO] running `"docker" "rm" "-f" "28181f6eafc559c8418a3b7bd4c0d049af187614402284a68f34e37eb467ca7f"`
[INFO] [stdout] 28181f6eafc559c8418a3b7bd4c0d049af187614402284a68f34e37eb467ca7f
[INFO] running `"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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-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" "+1.44.0" "test" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] c9a67912c937cc795f6d17c9c31c17700d2b3dd3787c60900fafe9445462c732
[INFO] running `"docker" "start" "-a" "c9a67912c937cc795f6d17c9c31c17700d2b3dd3787c60900fafe9445462c732"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr] warning: unused import: `std::iter`
[INFO] [stderr]    --> src/lib.rs:364:9
[INFO] [stderr]     |
[INFO] [stderr] 364 |     use std::iter;
[INFO] [stderr]     |         ^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `head`
[INFO] [stderr]    --> src/lib.rs:271:17
[INFO] [stderr]     |
[INFO] [stderr] 271 |             let head = match self.to_head() {
[INFO] [stderr]     |                 ^^^^ help: if this is intentional, prefix it with an underscore: `_head`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `nodes`
[INFO] [stderr]    --> src/data.rs:501:13
[INFO] [stderr]     |
[INFO] [stderr] 501 |             nodes: Vec<T>,
[INFO] [stderr]     |             ^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]    --> src/data.rs:681:13
[INFO] [stderr]     |
[INFO] [stderr] 681 |             pub fn new() -> Trie {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `contains`
[INFO] [stderr]    --> src/data.rs:688:13
[INFO] [stderr]     |
[INFO] [stderr] 688 |             pub fn contains(&self, t: &str) -> bool {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `contains_prefix`
[INFO] [stderr]    --> src/data.rs:696:13
[INFO] [stderr]     |
[INFO] [stderr] 696 |             pub fn contains_prefix(&self, t: &str) -> bool {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `child_matches`
[INFO] [stderr]    --> src/data.rs:700:13
[INFO] [stderr]     |
[INFO] [stderr] 700 |             fn child_matches(&self, t: &str) -> Option<&Trie> {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `add`
[INFO] [stderr]    --> src/data.rs:716:13
[INFO] [stderr]     |
[INFO] [stderr] 716 |             pub fn add(&mut self, values: &str) {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `add_chars`
[INFO] [stderr]    --> src/data.rs:721:13
[INFO] [stderr]     |
[INFO] [stderr] 721 |             fn add_chars(&mut self, values: &mut Chars) {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `add_char`
[INFO] [stderr]    --> src/data.rs:731:13
[INFO] [stderr]     |
[INFO] [stderr] 731 |             fn add_char(&mut self, value: char) -> usize {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `set_complete`
[INFO] [stderr]    --> src/data.rs:747:13
[INFO] [stderr]     |
[INFO] [stderr] 747 |             fn set_complete(&mut self) {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 11 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::iter`
[INFO] [stderr]    --> src/lib.rs:364:9
[INFO] [stderr]     |
[INFO] [stderr] 364 |     use std::iter;
[INFO] [stderr]     |         ^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `head`
[INFO] [stderr]    --> src/lib.rs:271:17
[INFO] [stderr]     |
[INFO] [stderr] 271 |             let head = match self.to_head() {
[INFO] [stderr]     |                 ^^^^ help: if this is intentional, prefix it with an underscore: `_head`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `nodes`
[INFO] [stderr]    --> src/data.rs:501:13
[INFO] [stderr]     |
[INFO] [stderr] 501 |             nodes: Vec<T>,
[INFO] [stderr]     |             ^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]    --> src/lib.rs:346:13
[INFO] [stderr]     |
[INFO] [stderr] 346 |             graph.add_edge(a, b);
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]    --> src/lib.rs:351:13
[INFO] [stderr]     |
[INFO] [stderr] 351 |             graph.add_edge(c, d);
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]    --> src/lib.rs:352:13
[INFO] [stderr]     |
[INFO] [stderr] 352 |             graph.add_edge(d, c);
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: 6 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.07s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/algorithms-0fe77651efae52d7
[INFO] [stdout] 
[INFO] [stdout] running 26 tests
[INFO] [stdout] test data::data::hash_set::tests::test_clear ... ok
[INFO] [stdout] test data::data::trie::tests::test_contains ... ok
[INFO] [stdout] test data::data::stack::tests::test_push_pop ... ok
[INFO] [stdout] test data::data::hash_set::tests::test_contains ... ok
[INFO] [stdout] test data::data::hash_set::tests::test_is_empty ... ok
[INFO] [stdout] test data::data::stack::tests::test_peek_size_is_empty ... ok
[INFO] [stdout] test linked_list::tests::test_peek ... ok
[INFO] [stdout] test linked_list::tests::test_peek_mut ... ok
[INFO] [stdout] test linked_list::tests::test_push_pop ... ok
[INFO] [stdout] test old_graph::tests::test_is_tree ... ok
[INFO] [stdout] test linked_list::tests::test_empty ... ok
[INFO] [stdout] test data::data::hash_set::tests::test_add_remove ... ok
[INFO] [stdout] test linked_list::tests::test_iter_mut ... ok
[INFO] [stdout] test data::data::hash_set2::tests::test_contains ... ok
[INFO] [stdout] test data::data::graph::tests::test_dfs ... ok
[INFO] [stdout] test data::data::graph::tests::test_bfs ... ok
[INFO] [stdout] test data::data::hash_set2::tests::test_is_empty ... ok
[INFO] [stdout] test linked_list::tests::test_into_iter ... ok
[INFO] [stdout] test data::data::hash_set2::tests::test_add_remove ... ok
[INFO] [stdout] test linked_list::tests::test_iter ... ok
[INFO] [stdout] test data::data::hash_set2::tests::test_clear ... ok
[INFO] [stdout] test primes::tests::test_sieve_of_eratosthenes_odds ... ok
[INFO] [stdout] test primes::tests::test_sieve_of_eratosthenes_naive ... ok
[INFO] [stdout] test data::data::hash_set::tests::test_benchmarks_tolerable ... ok
[INFO] [stdout] test primes::tests::test_trial_division ... ok
[INFO] [stdout] test data::data::hash_set2::tests::test_benchmarks_tolerable ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 26 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/algorithms-56c41dace11effcc
[INFO] [stderr]    Doc-tests algorithms
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `"docker" "inspect" "c9a67912c937cc795f6d17c9c31c17700d2b3dd3787c60900fafe9445462c732"`
[INFO] running `"docker" "rm" "-f" "c9a67912c937cc795f6d17c9c31c17700d2b3dd3787c60900fafe9445462c732"`
[INFO] [stdout] c9a67912c937cc795f6d17c9c31c17700d2b3dd3787c60900fafe9445462c732