[INFO] cloning repository https://github.com/CaioLC/linked-lists
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/CaioLC/linked-lists" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCaioLC%2Flinked-lists", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCaioLC%2Flinked-lists'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] aa3dd1b6e9c6efb88a346221d5839fc2c027621c
[INFO] building CaioLC/linked-lists against try#334963c956d25708feab489a3816ae63f639355d for pr-135216
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCaioLC%2Flinked-lists" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/CaioLC/linked-lists on toolchain 334963c956d25708feab489a3816ae63f639355d
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+334963c956d25708feab489a3816ae63f639355d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/CaioLC/linked-lists
[INFO] finished tweaking git repo https://github.com/CaioLC/linked-lists
[INFO] tweaked toml for git repo https://github.com/CaioLC/linked-lists written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/CaioLC/linked-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" "+334963c956d25708feab489a3816ae63f639355d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+334963c956d25708feab489a3816ae63f639355d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5dd7f12681d30b0d823fb639fef5c1c84fdb5328d0cc8835a9eedc1022fcd640
[INFO] running `Command { std: "docker" "start" "-a" "5dd7f12681d30b0d823fb639fef5c1c84fdb5328d0cc8835a9eedc1022fcd640", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5dd7f12681d30b0d823fb639fef5c1c84fdb5328d0cc8835a9eedc1022fcd640", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5dd7f12681d30b0d823fb639fef5c1c84fdb5328d0cc8835a9eedc1022fcd640", kill_on_drop: false }`
[INFO] [stdout] 5dd7f12681d30b0d823fb639fef5c1c84fdb5328d0cc8835a9eedc1022fcd640
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+334963c956d25708feab489a3816ae63f639355d" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 14cd81f6d74d8497814d742680cc1a496b56184f1abeaf688f984adb92438e5b
[INFO] running `Command { std: "docker" "start" "-a" "14cd81f6d74d8497814d742680cc1a496b56184f1abeaf688f984adb92438e5b", kill_on_drop: false }`
[INFO] [stderr]    Compiling linked_lists v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: struct `List` is never constructed
[INFO] [stdout]  --> src/fourth.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | struct List<T> {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `Link` is never used
[INFO] [stdout]  --> src/fourth.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/fourth.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/fourth.rs:18:8
[INFO] [stdout]    |
[INFO] [stdout] 17 | impl<T> Node<T> {
[INFO] [stdout]    | --------------- associated function in this implementation
[INFO] [stdout] 18 |     fn new(elem: T) -> Rc<RefCell<Node<T>>> {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `push_front`, `pop_front`, and `peek_front` are never used
[INFO] [stdout]   --> src/fourth.rs:30:12
[INFO] [stdout]    |
[INFO] [stdout] 29 | impl<T> List<T> {
[INFO] [stdout]    | --------------- associated items in this implementation
[INFO] [stdout] 30 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 34 |     pub fn push_front(&mut self, elem: T) {
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 52 |     pub fn pop_front(&mut self) -> Option<T> {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 67 |     pub fn peek_front(&self) -> Option<Ref<T>> {
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.39s
[INFO] running `Command { std: "docker" "inspect" "14cd81f6d74d8497814d742680cc1a496b56184f1abeaf688f984adb92438e5b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "14cd81f6d74d8497814d742680cc1a496b56184f1abeaf688f984adb92438e5b", kill_on_drop: false }`
[INFO] [stdout] 14cd81f6d74d8497814d742680cc1a496b56184f1abeaf688f984adb92438e5b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+334963c956d25708feab489a3816ae63f639355d" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 92a0a080574db6016d99a93b0fc5ada6ddada227623bad79359e86b79f8acce8
[INFO] running `Command { std: "docker" "start" "-a" "92a0a080574db6016d99a93b0fc5ada6ddada227623bad79359e86b79f8acce8", kill_on_drop: false }`
[INFO] [stdout] warning: struct `List` is never constructed
[INFO] [stdout]  --> src/fourth.rs:4:8
[INFO] [stdout]   |
[INFO] [stdout] 4 | struct List<T> {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `Link` is never used
[INFO] [stdout]  --> src/fourth.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/fourth.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/fourth.rs:18:8
[INFO] [stdout]    |
[INFO] [stdout] 17 | impl<T> Node<T> {
[INFO] [stdout]    | --------------- associated function in this implementation
[INFO] [stdout] 18 |     fn new(elem: T) -> Rc<RefCell<Node<T>>> {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `push_front`, `pop_front`, and `peek_front` are never used
[INFO] [stdout]   --> src/fourth.rs:30:12
[INFO] [stdout]    |
[INFO] [stdout] 29 | impl<T> List<T> {
[INFO] [stdout]    | --------------- associated items in this implementation
[INFO] [stdout] 30 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 34 |     pub fn push_front(&mut self, elem: T) {
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 52 |     pub fn pop_front(&mut self) -> Option<T> {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 67 |     pub fn peek_front(&self) -> Option<Ref<T>> {
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling linked_lists v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]    --> src/fourth.rs:113:13
[INFO] [stdout]     |
[INFO] [stdout] 113 |         let a = *list.peek_front().unwrap();
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.62s
[INFO] running `Command { std: "docker" "inspect" "92a0a080574db6016d99a93b0fc5ada6ddada227623bad79359e86b79f8acce8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "92a0a080574db6016d99a93b0fc5ada6ddada227623bad79359e86b79f8acce8", kill_on_drop: false }`
[INFO] [stdout] 92a0a080574db6016d99a93b0fc5ada6ddada227623bad79359e86b79f8acce8
