[INFO] cloning repository https://github.com/przprz/too-many-lists
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/przprz/too-many-lists" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fprzprz%2Ftoo-many-lists", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fprzprz%2Ftoo-many-lists'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8177291c9406e25a00ec9fd16ae97596a7a8be53
[INFO] checking przprz/too-many-lists against try#3fada14ee01d755dc8076e611f11bf65b28ffd21 for pr-154971-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fprzprz%2Ftoo-many-lists" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/przprz/too-many-lists
[INFO] finished tweaking git repo https://github.com/przprz/too-many-lists
[INFO] tweaked toml for git repo https://github.com/przprz/too-many-lists written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/przprz/too-many-lists on toolchain 3fada14ee01d755dc8076e611f11bf65b28ffd21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3fada14ee01d755dc8076e611f11bf65b28ffd21" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/przprz/too-many-lists already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3fada14ee01d755dc8076e611f11bf65b28ffd21" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+3fada14ee01d755dc8076e611f11bf65b28ffd21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 708d9ec8e65f7bf7a9b20aae50041c22098b2735a7d5c0778068521a1f0189fd
[INFO] running `Command { std: "docker" "start" "-a" "708d9ec8e65f7bf7a9b20aae50041c22098b2735a7d5c0778068521a1f0189fd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "708d9ec8e65f7bf7a9b20aae50041c22098b2735a7d5c0778068521a1f0189fd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "708d9ec8e65f7bf7a9b20aae50041c22098b2735a7d5c0778068521a1f0189fd", kill_on_drop: false }`
[INFO] [stdout] 708d9ec8e65f7bf7a9b20aae50041c22098b2735a7d5c0778068521a1f0189fd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/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" "RUSTDOCFLAGS=--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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+3fada14ee01d755dc8076e611f11bf65b28ffd21" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6e4d0e4a46614c82fcc87bccdfb07fe8a734a700ffbd8b18fbc49a293dc17a33
[INFO] running `Command { std: "docker" "start" "-a" "6e4d0e4a46614c82fcc87bccdfb07fe8a734a700ffbd8b18fbc49a293dc17a33", kill_on_drop: false }`
[INFO] [stderr]     Checking a-bad-stack v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: struct `List` is never constructed
[INFO] [stdout]  --> src/second.rs:6:12
[INFO] [stdout]   |
[INFO] [stdout] 6 | pub struct List<T> {
[INFO] [stdout]   |            ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `Link` is never used
[INFO] [stdout]   --> src/second.rs:10:6
[INFO] [stdout]    |
[INFO] [stdout] 10 | type Link<T> = Option<Box<Node<T>>>;
[INFO] [stdout]    |      ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Node` is never constructed
[INFO] [stdout]   --> src/second.rs:12:8
[INFO] [stdout]    |
[INFO] [stdout] 12 | struct Node<T> {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Iter` is never constructed
[INFO] [stdout]   --> src/second.rs:17:12
[INFO] [stdout]    |
[INFO] [stdout] 17 | pub struct Iter<'a, T> {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `iter`, `new`, `push`, and `pop` are never used
[INFO] [stdout]   --> src/second.rs:33:12
[INFO] [stdout]    |
[INFO] [stdout] 32 | impl<T> List<T> {
[INFO] [stdout]    | --------------- associated items in this implementation
[INFO] [stdout] 33 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 37 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 41 |     pub fn push(&mut self, elem: T) -> &mut List<T> {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 51 |     pub fn pop(&mut self) -> Option<T> {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `List` is never constructed
[INFO] [stdout]  --> src/fifth.rs:4:12
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub struct List<T> {
[INFO] [stdout]   |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `Link` is never used
[INFO] [stdout]  --> src/fifth.rs:9:6
[INFO] [stdout]   |
[INFO] [stdout] 9 | type Link<T> = Option<Rc<RefCell<Node<T>>>>;
[INFO] [stdout]   |      ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Node` is never constructed
[INFO] [stdout]   --> src/fifth.rs:11:8
[INFO] [stdout]    |
[INFO] [stdout] 11 | struct Node<T> {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/fifth.rs:19:8
[INFO] [stdout]    |
[INFO] [stdout] 18 | impl<T> Node<T> {
[INFO] [stdout]    | --------------- associated function in this implementation
[INFO] [stdout] 19 |     fn new(elem: T) -> Rc<RefCell<Self>> {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: multiple associated items are never used
[INFO] [stdout]    --> src/fifth.rs:29:12
[INFO] [stdout]     |
[INFO] [stdout]  28 | impl<T> List<T> {
[INFO] [stdout]     | --------------- associated items in this implementation
[INFO] [stdout]  29 |     pub fn new() -> Self {
[INFO] [stdout]     |            ^^^
[INFO] [stdout] ...
[INFO] [stdout]  33 |     pub fn push_front(&mut self, elem: T) {
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout]  48 |     pub fn push_back(&mut self, elem: T) {
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout]  63 |     pub fn pop_back(&mut self) -> Option<T> {
[INFO] [stdout]     |            ^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout]  78 |     pub fn pop_front(&mut self) -> Option<T> {
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout]  93 |     pub fn peek_front(&self) -> Option<Ref<T>> {
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout]  99 |     pub fn peek_back(&self) -> Option<Ref<T>> {
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 105 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stdout]     |            ^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 111 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 117 |     pub fn into_iter(self) -> IntoIter<T> {
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `IntoIter` is never constructed
[INFO] [stdout]    --> src/fifth.rs:128:12
[INFO] [stdout]     |
[INFO] [stdout] 128 | pub struct IntoIter<T>(List<T>);
[INFO] [stdout]     |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/second.rs:33:17
[INFO] [stdout]    |
[INFO] [stdout] 33 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stdout]    |                 ^^^^^     ^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |                 |
[INFO] [stdout]    |                 the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 33 |     pub fn iter(&self) -> Iter<'_, T> {
[INFO] [stdout]    |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/fifth.rs:93:23
[INFO] [stdout]    |
[INFO] [stdout] 93 |     pub fn peek_front(&self) -> Option<Ref<T>> {
[INFO] [stdout]    |                       ^^^^^            ^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |                       |
[INFO] [stdout]    |                       the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 93 |     pub fn peek_front(&self) -> Option<Ref<'_, T>> {
[INFO] [stdout]    |                                            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/fifth.rs:99:22
[INFO] [stdout]    |
[INFO] [stdout] 99 |     pub fn peek_back(&self) -> Option<Ref<T>> {
[INFO] [stdout]    |                      ^^^^^            ^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |                      |
[INFO] [stdout]    |                      the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 99 |     pub fn peek_back(&self) -> Option<Ref<'_, T>> {
[INFO] [stdout]    |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/fifth.rs:105:26
[INFO] [stdout]     |
[INFO] [stdout] 105 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stdout]     |                          ^^^^^^^^^            ^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                          |
[INFO] [stdout]     |                          the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 105 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stdout]     |                                                      +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/fifth.rs:111:27
[INFO] [stdout]     |
[INFO] [stdout] 111 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stdout]     |                           ^^^^^^^^^            ^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                           |
[INFO] [stdout]     |                           the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 111 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stdout]     |                                                       +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/second.rs:33:17
[INFO] [stdout]    |
[INFO] [stdout] 33 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stdout]    |                 ^^^^^     ^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |                 |
[INFO] [stdout]    |                 the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 33 |     pub fn iter(&self) -> Iter<'_, T> {
[INFO] [stdout]    |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/fifth.rs:93:23
[INFO] [stdout]    |
[INFO] [stdout] 93 |     pub fn peek_front(&self) -> Option<Ref<T>> {
[INFO] [stdout]    |                       ^^^^^            ^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |                       |
[INFO] [stdout]    |                       the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 93 |     pub fn peek_front(&self) -> Option<Ref<'_, T>> {
[INFO] [stdout]    |                                            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/fifth.rs:99:22
[INFO] [stdout]    |
[INFO] [stdout] 99 |     pub fn peek_back(&self) -> Option<Ref<T>> {
[INFO] [stdout]    |                      ^^^^^            ^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |                      |
[INFO] [stdout]    |                      the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 99 |     pub fn peek_back(&self) -> Option<Ref<'_, T>> {
[INFO] [stdout]    |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/fifth.rs:105:26
[INFO] [stdout]     |
[INFO] [stdout] 105 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stdout]     |                          ^^^^^^^^^            ^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                          |
[INFO] [stdout]     |                          the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 105 |     pub fn peek_back_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stdout]     |                                                      +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/fifth.rs:111:27
[INFO] [stdout]     |
[INFO] [stdout] 111 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<T>> {
[INFO] [stdout]     |                           ^^^^^^^^^            ^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                           |
[INFO] [stdout]     |                           the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 111 |     pub fn peek_front_mut(&mut self) -> Option<RefMut<'_, T>> {
[INFO] [stdout]     |                                                       +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.32s
[INFO] running `Command { std: "docker" "inspect" "6e4d0e4a46614c82fcc87bccdfb07fe8a734a700ffbd8b18fbc49a293dc17a33", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6e4d0e4a46614c82fcc87bccdfb07fe8a734a700ffbd8b18fbc49a293dc17a33", kill_on_drop: false }`
[INFO] [stdout] 6e4d0e4a46614c82fcc87bccdfb07fe8a734a700ffbd8b18fbc49a293dc17a33
