[INFO] updating cached repository https://github.com/ryota-sakamoto/rust_study
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/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] 5eb4f8bec1711983c25dcc199f9e5c1cb2a2aa47
[INFO] testing ryota-sakamoto/rust_study against beta-2019-09-28 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fryota-sakamoto%2Frust_study" "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/ryota-sakamoto/rust_study on toolchain beta-2019-09-28
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+beta-2019-09-28" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/ryota-sakamoto/rust_study
[INFO] finished tweaking git repo https://github.com/ryota-sakamoto/rust_study
[INFO] tweaked toml for git repo https://github.com/ryota-sakamoto/rust_study written to work/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/ryota-sakamoto/rust_study already has a lockfile, it will not be regenerated
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+beta-2019-09-28" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-6/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/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=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" "+beta-2019-09-28" "build" "--frozen"`
[INFO] [stdout] 4435909d5f4456e85067fea015b88b96df56271bac24bc39af10fee0b84af019
[INFO] running `"docker" "start" "-a" "4435909d5f4456e85067fea015b88b96df56271bac24bc39af10fee0b84af019"`
[INFO] [stderr]    Compiling rust_test v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused macro definition
[INFO] [stderr]   --> src/list.rs:53:1
[INFO] [stderr]    |
[INFO] [stderr] 53 | / macro_rules! list {
[INFO] [stderr] 54 | |     ($($n: expr),*) => {
[INFO] [stderr] 55 | |         {
[INFO] [stderr] 56 | |             let mut list = List::empty_list();
[INFO] [stderr] ...  |
[INFO] [stderr] 74 | |     };
[INFO] [stderr] 75 | | }
[INFO] [stderr]    | |_^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_macros)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `call`
[INFO] [stderr]  --> src/module.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn call() {
[INFO] [stderr]   | ^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Nil`
[INFO] [stderr]  --> src/list.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 |     Nil,
[INFO] [stderr]   |     ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `List`
[INFO] [stderr]  --> src/list.rs:6:5
[INFO] [stderr]   |
[INFO] [stderr] 6 | /     List {
[INFO] [stderr] 7 | |         head: T,
[INFO] [stderr] 8 | |         tail: Box<List<T>>,
[INFO] [stderr] 9 | |     }
[INFO] [stderr]   | |_____^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `empty_list`
[INFO] [stderr]   --> src/list.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 |     pub fn empty_list() -> List<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `prepend`
[INFO] [stderr]   --> src/list.rs:17:5
[INFO] [stderr]    |
[INFO] [stderr] 17 |     pub fn prepend(self, t: T) -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `head`
[INFO] [stderr]   --> src/list.rs:24:5
[INFO] [stderr]    |
[INFO] [stderr] 24 |     pub fn head(&self) -> &T {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `last`
[INFO] [stderr]   --> src/list.rs:31:5
[INFO] [stderr]    |
[INFO] [stderr] 31 |     pub fn last(&self) -> &T {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `is_empty`
[INFO] [stderr]   --> src/list.rs:44:5
[INFO] [stderr]    |
[INFO] [stderr] 44 |     fn is_empty(&self) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `tailrec`
[INFO] [stderr]   --> src/list.rs:87:1
[INFO] [stderr]    |
[INFO] [stderr] 87 | fn tailrec<T: Debug>(list: &List<T>) {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: the `head:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:27:26
[INFO] [stderr]    |
[INFO] [stderr] 27 |             &List::List {head: ref head, tail: _} => head,
[INFO] [stderr]    |                          -----^^^^^^^^^
[INFO] [stderr]    |                          |
[INFO] [stderr]    |                          help: remove this
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(non_shorthand_field_patterns)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: the `head:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:34:26
[INFO] [stderr]    |
[INFO] [stderr] 34 |             &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                          -----^^^^^^^^^
[INFO] [stderr]    |                          |
[INFO] [stderr]    |                          help: remove this
[INFO] [stderr] 
[INFO] [stderr] warning: the `tail:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:34:42
[INFO] [stderr]    |
[INFO] [stderr] 34 |             &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                                          -----^^^^^^^^^
[INFO] [stderr]    |                                          |
[INFO] [stderr]    |                                          help: remove this
[INFO] [stderr] 
[INFO] [stderr] warning: the `head:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:90:22
[INFO] [stderr]    |
[INFO] [stderr] 90 |         &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                      -----^^^^^^^^^
[INFO] [stderr]    |                      |
[INFO] [stderr]    |                      help: remove this
[INFO] [stderr] 
[INFO] [stderr] warning: the `tail:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:90:38
[INFO] [stderr]    |
[INFO] [stderr] 90 |         &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                                      -----^^^^^^^^^
[INFO] [stderr]    |                                      |
[INFO] [stderr]    |                                      help: remove this
[INFO] [stderr] 
[INFO] [stderr] warning: unused macro definition
[INFO] [stderr]   --> src/list.rs:53:1
[INFO] [stderr]    |
[INFO] [stderr] 53 | / macro_rules! list {
[INFO] [stderr] 54 | |     ($($n: expr),*) => {
[INFO] [stderr] 55 | |         {
[INFO] [stderr] 56 | |             let mut list = List::empty_list();
[INFO] [stderr] ...  |
[INFO] [stderr] 74 | |     };
[INFO] [stderr] 75 | | }
[INFO] [stderr]    | |_^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_macros)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/main.rs:78:19
[INFO] [stderr]    |
[INFO] [stderr] 78 |     let func: Box<Fn(u64) -> u64> = Box::new(|a| a.pow(2));
[INFO] [stderr]    |                   ^^^^^^^^^^^^^^ help: use `dyn`: `dyn Fn(u64) -> u64`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `head`
[INFO] [stderr]   --> src/list.rs:24:5
[INFO] [stderr]    |
[INFO] [stderr] 24 |     pub fn head(&self) -> &T {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `last`
[INFO] [stderr]   --> src/list.rs:31:5
[INFO] [stderr]    |
[INFO] [stderr] 31 |     pub fn last(&self) -> &T {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `is_empty`
[INFO] [stderr]   --> src/list.rs:44:5
[INFO] [stderr]    |
[INFO] [stderr] 44 |     fn is_empty(&self) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `tailrec`
[INFO] [stderr]   --> src/list.rs:87:1
[INFO] [stderr]    |
[INFO] [stderr] 87 | fn tailrec<T: Debug>(list: &List<T>) {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: the `head:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:27:26
[INFO] [stderr]    |
[INFO] [stderr] 27 |             &List::List {head: ref head, tail: _} => head,
[INFO] [stderr]    |                          -----^^^^^^^^^
[INFO] [stderr]    |                          |
[INFO] [stderr]    |                          help: remove this
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(non_shorthand_field_patterns)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: the `head:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:34:26
[INFO] [stderr]    |
[INFO] [stderr] 34 |             &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                          -----^^^^^^^^^
[INFO] [stderr]    |                          |
[INFO] [stderr]    |                          help: remove this
[INFO] [stderr] 
[INFO] [stderr] warning: the `tail:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:34:42
[INFO] [stderr]    |
[INFO] [stderr] 34 |             &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                                          -----^^^^^^^^^
[INFO] [stderr]    |                                          |
[INFO] [stderr]    |                                          help: remove this
[INFO] [stderr] 
[INFO] [stderr] warning: the `head:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:90:22
[INFO] [stderr]    |
[INFO] [stderr] 90 |         &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                      -----^^^^^^^^^
[INFO] [stderr]    |                      |
[INFO] [stderr]    |                      help: remove this
[INFO] [stderr] 
[INFO] [stderr] warning: the `tail:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:90:38
[INFO] [stderr]    |
[INFO] [stderr] 90 |         &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                                      -----^^^^^^^^^
[INFO] [stderr]    |                                      |
[INFO] [stderr]    |                                      help: remove this
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.76s
[INFO] running `"docker" "inspect" "4435909d5f4456e85067fea015b88b96df56271bac24bc39af10fee0b84af019"`
[INFO] running `"docker" "rm" "-f" "4435909d5f4456e85067fea015b88b96df56271bac24bc39af10fee0b84af019"`
[INFO] [stdout] 4435909d5f4456e85067fea015b88b96df56271bac24bc39af10fee0b84af019
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-6/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/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=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" "+beta-2019-09-28" "test" "--frozen" "--no-run"`
[INFO] [stdout] 9a3be8d5a575736cd865f96e4757512415515891179f5a1091a615aade1d0c45
[INFO] running `"docker" "start" "-a" "9a3be8d5a575736cd865f96e4757512415515891179f5a1091a615aade1d0c45"`
[INFO] [stderr]    Compiling rust_test v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused macro definition
[INFO] [stderr]   --> src/list.rs:53:1
[INFO] [stderr]    |
[INFO] [stderr] 53 | / macro_rules! list {
[INFO] [stderr] 54 | |     ($($n: expr),*) => {
[INFO] [stderr] 55 | |         {
[INFO] [stderr] 56 | |             let mut list = List::empty_list();
[INFO] [stderr] ...  |
[INFO] [stderr] 74 | |     };
[INFO] [stderr] 75 | | }
[INFO] [stderr]    | |_^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_macros)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused macro definition
[INFO] [stderr]   --> src/list.rs:53:1
[INFO] [stderr]    |
[INFO] [stderr] 53 | / macro_rules! list {
[INFO] [stderr] 54 | |     ($($n: expr),*) => {
[INFO] [stderr] 55 | |         {
[INFO] [stderr] 56 | |             let mut list = List::empty_list();
[INFO] [stderr] ...  |
[INFO] [stderr] 74 | |     };
[INFO] [stderr] 75 | | }
[INFO] [stderr]    | |_^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_macros)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/main.rs:78:19
[INFO] [stderr]    |
[INFO] [stderr] 78 |     let func: Box<Fn(u64) -> u64> = Box::new(|a| a.pow(2));
[INFO] [stderr]    |                   ^^^^^^^^^^^^^^ help: use `dyn`: `dyn Fn(u64) -> u64`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `call`
[INFO] [stderr]  --> src/module.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn call() {
[INFO] [stderr]   | ^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Nil`
[INFO] [stderr]  --> src/list.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 |     Nil,
[INFO] [stderr]   |     ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `List`
[INFO] [stderr]  --> src/list.rs:6:5
[INFO] [stderr]   |
[INFO] [stderr] 6 | /     List {
[INFO] [stderr] 7 | |         head: T,
[INFO] [stderr] 8 | |         tail: Box<List<T>>,
[INFO] [stderr] 9 | |     }
[INFO] [stderr]   | |_____^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `empty_list`
[INFO] [stderr]   --> src/list.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 |     pub fn empty_list() -> List<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `prepend`
[INFO] [stderr]   --> src/list.rs:17:5
[INFO] [stderr]    |
[INFO] [stderr] 17 |     pub fn prepend(self, t: T) -> Self {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `head`
[INFO] [stderr]   --> src/list.rs:24:5
[INFO] [stderr]    |
[INFO] [stderr] 24 |     pub fn head(&self) -> &T {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `last`
[INFO] [stderr]   --> src/list.rs:31:5
[INFO] [stderr]    |
[INFO] [stderr] 31 |     pub fn last(&self) -> &T {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `is_empty`
[INFO] [stderr]   --> src/list.rs:44:5
[INFO] [stderr]    |
[INFO] [stderr] 44 |     fn is_empty(&self) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `tailrec`
[INFO] [stderr]   --> src/list.rs:87:1
[INFO] [stderr]    |
[INFO] [stderr] 87 | fn tailrec<T: Debug>(list: &List<T>) {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: the `head:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:27:26
[INFO] [stderr]    |
[INFO] [stderr] 27 |             &List::List {head: ref head, tail: _} => head,
[INFO] [stderr]    |                          -----^^^^^^^^^
[INFO] [stderr]    |                          |
[INFO] [stderr]    |                          help: remove this
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(non_shorthand_field_patterns)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: the `head:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:34:26
[INFO] [stderr]    |
[INFO] [stderr] 34 |             &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                          -----^^^^^^^^^
[INFO] [stderr]    |                          |
[INFO] [stderr]    |                          help: remove this
[INFO] [stderr] 
[INFO] [stderr] warning: the `tail:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:34:42
[INFO] [stderr]    |
[INFO] [stderr] 34 |             &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                                          -----^^^^^^^^^
[INFO] [stderr]    |                                          |
[INFO] [stderr]    |                                          help: remove this
[INFO] [stderr] 
[INFO] [stderr] warning: the `head:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:90:22
[INFO] [stderr]    |
[INFO] [stderr] 90 |         &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                      -----^^^^^^^^^
[INFO] [stderr]    |                      |
[INFO] [stderr]    |                      help: remove this
[INFO] [stderr] 
[INFO] [stderr] warning: the `tail:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:90:38
[INFO] [stderr]    |
[INFO] [stderr] 90 |         &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                                      -----^^^^^^^^^
[INFO] [stderr]    |                                      |
[INFO] [stderr]    |                                      help: remove this
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `head`
[INFO] [stderr]   --> src/list.rs:24:5
[INFO] [stderr]    |
[INFO] [stderr] 24 |     pub fn head(&self) -> &T {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `last`
[INFO] [stderr]   --> src/list.rs:31:5
[INFO] [stderr]    |
[INFO] [stderr] 31 |     pub fn last(&self) -> &T {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `is_empty`
[INFO] [stderr]   --> src/list.rs:44:5
[INFO] [stderr]    |
[INFO] [stderr] 44 |     fn is_empty(&self) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `tailrec`
[INFO] [stderr]   --> src/list.rs:87:1
[INFO] [stderr]    |
[INFO] [stderr] 87 | fn tailrec<T: Debug>(list: &List<T>) {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: the `head:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:27:26
[INFO] [stderr]    |
[INFO] [stderr] 27 |             &List::List {head: ref head, tail: _} => head,
[INFO] [stderr]    |                          -----^^^^^^^^^
[INFO] [stderr]    |                          |
[INFO] [stderr]    |                          help: remove this
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(non_shorthand_field_patterns)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: the `head:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:34:26
[INFO] [stderr]    |
[INFO] [stderr] 34 |             &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                          -----^^^^^^^^^
[INFO] [stderr]    |                          |
[INFO] [stderr]    |                          help: remove this
[INFO] [stderr] 
[INFO] [stderr] warning: the `tail:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:34:42
[INFO] [stderr]    |
[INFO] [stderr] 34 |             &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                                          -----^^^^^^^^^
[INFO] [stderr]    |                                          |
[INFO] [stderr]    |                                          help: remove this
[INFO] [stderr] 
[INFO] [stderr] warning: the `head:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:90:22
[INFO] [stderr]    |
[INFO] [stderr] 90 |         &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                      -----^^^^^^^^^
[INFO] [stderr]    |                      |
[INFO] [stderr]    |                      help: remove this
[INFO] [stderr] 
[INFO] [stderr] warning: the `tail:` in this pattern is redundant
[INFO] [stderr]   --> src/list.rs:90:38
[INFO] [stderr]    |
[INFO] [stderr] 90 |         &List::List {head: ref head, tail: ref tail} => {
[INFO] [stderr]    |                                      -----^^^^^^^^^
[INFO] [stderr]    |                                      |
[INFO] [stderr]    |                                      help: remove this
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.52s
[INFO] running `"docker" "inspect" "9a3be8d5a575736cd865f96e4757512415515891179f5a1091a615aade1d0c45"`
[INFO] running `"docker" "rm" "-f" "9a3be8d5a575736cd865f96e4757512415515891179f5a1091a615aade1d0c45"`
[INFO] [stdout] 9a3be8d5a575736cd865f96e4757512415515891179f5a1091a615aade1d0c45
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-6/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/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=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" "+beta-2019-09-28" "test" "--frozen"`
[INFO] [stdout] f00cc4c84bf00c6710ef4c51a5f5c3fd1e4e3187f1dac73f46d17c3f33c8aec6
[INFO] running `"docker" "start" "-a" "f00cc4c84bf00c6710ef4c51a5f5c3fd1e4e3187f1dac73f46d17c3f33c8aec6"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/rust_test-abf0202a84d0a05e
[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] [stderr]      Running /opt/rustwide/target/debug/deps/rust_test-940278ac17227cfa
[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] [stderr]    Doc-tests rust_test
[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" "f00cc4c84bf00c6710ef4c51a5f5c3fd1e4e3187f1dac73f46d17c3f33c8aec6"`
[INFO] running `"docker" "rm" "-f" "f00cc4c84bf00c6710ef4c51a5f5c3fd1e4e3187f1dac73f46d17c3f33c8aec6"`
[INFO] [stdout] f00cc4c84bf00c6710ef4c51a5f5c3fd1e4e3187f1dac73f46d17c3f33c8aec6