[INFO] cloning repository https://github.com/link-a/learning-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/link-a/learning-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flink-a%2Flearning-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flink-a%2Flearning-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 5cfe739935d47058eacef6536a5a34cefc528368
[INFO] checking link-a/learning-rust against beta for pr-78714
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flink-a%2Flearning-rust" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/link-a/learning-rust on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/link-a/learning-rust
[INFO] finished tweaking git repo https://github.com/link-a/learning-rust
[INFO] tweaked toml for git repo https://github.com/link-a/learning-rust written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/link-a/learning-rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 39c5a2f6b7ca6855bdb1973db2a9506711b317ae61accfe4ca3da37e547694e8
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "39c5a2f6b7ca6855bdb1973db2a9506711b317ae61accfe4ca3da37e547694e8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "39c5a2f6b7ca6855bdb1973db2a9506711b317ae61accfe4ca3da37e547694e8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "39c5a2f6b7ca6855bdb1973db2a9506711b317ae61accfe4ca3da37e547694e8", kill_on_drop: false }`
[INFO] [stdout] 39c5a2f6b7ca6855bdb1973db2a9506711b317ae61accfe4ca3da37e547694e8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] a153fc38191196060b15f56471d1efb7297aa92ca820013b6322f504b480ebe8
[INFO] running `Command { std: "docker" "start" "-a" "a153fc38191196060b15f56471d1efb7297aa92ca820013b6322f504b480ebe8", kill_on_drop: false }`
[INFO] [stderr]     Checking bloom v0.3.2
[INFO] [stderr]     Checking ctci v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: struct is never constructed: `Solution`
[INFO] [stdout]   --> src/bin/min_depth_binary_tree.rs:24:8
[INFO] [stdout]    |
[INFO] [stdout] 24 | struct Solution {}
[INFO] [stdout]    |        ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `min_depth`
[INFO] [stdout]   --> src/bin/min_depth_binary_tree.rs:27:12
[INFO] [stdout]    |
[INFO] [stdout] 27 |     pub fn min_depth(root: Option<Rc<RefCell<TreeNode>>>) -> i32 {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `l`
[INFO] [stdout]   --> src/bin/ref_playground.rs:59:13
[INFO] [stdout]    |
[INFO] [stdout] 59 |         let l = &(r.left);
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_l`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::borrow::Borrow`
[INFO] [stdout]  --> src/bin/ref_cells.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cell::RefCell`
[INFO] [stdout]  --> src/bin/ref_cells.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cell::RefCell;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::mem`
[INFO] [stdout]  --> src/bin/ref_cells.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::mem;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::rc::Rc`
[INFO] [stdout]  --> src/bin/ref_cells.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::rc::Rc;
[INFO] [stdout]   |     ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::mem`
[INFO] [stdout]    --> src/bin/ref_cells.rs:228:9
[INFO] [stdout]     |
[INFO] [stdout] 228 |     use std::mem;
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::VecDeque`
[INFO] [stdout]  --> src/bin/ref_playground.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::collections::VecDeque;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `NaiveSolution`
[INFO] [stdout]  --> src/bin/max_distance_in_arrays.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct NaiveSolution {}
[INFO] [stdout]   |        ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `max_distance`
[INFO] [stdout]  --> src/bin/max_distance_in_arrays.rs:5:12
[INFO] [stdout]   |
[INFO] [stdout] 5 |     pub fn max_distance(arrays: Vec<Vec<i32>>) -> i32 {
[INFO] [stdout]   |            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `FastestSolution`
[INFO] [stdout]   --> src/bin/max_distance_in_arrays.rs:23:8
[INFO] [stdout]    |
[INFO] [stdout] 23 | struct FastestSolution {}
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `max_distance`
[INFO] [stdout]   --> src/bin/max_distance_in_arrays.rs:26:12
[INFO] [stdout]    |
[INFO] [stdout] 26 |     pub fn max_distance(arrays: Vec<Vec<i32>>) -> i32 {
[INFO] [stdout]    |            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `DPSolution`
[INFO] [stdout]  --> src/bin/house_robber_ii.rs:2:8
[INFO] [stdout]   |
[INFO] [stdout] 2 | struct DPSolution {}
[INFO] [stdout]   |        ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `rob_simple`
[INFO] [stdout]  --> src/bin/house_robber_ii.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 |     fn rob_simple(nums: &[i32]) -> i32 {
[INFO] [stdout]   |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `rob`
[INFO] [stdout]   --> src/bin/house_robber_ii.rs:16:12
[INFO] [stdout]    |
[INFO] [stdout] 16 |     pub fn rob(nums: Vec<i32>) -> i32 {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::borrow::Borrow`
[INFO] [stdout]  --> src/bin/ref_cells.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cell::RefCell`
[INFO] [stdout]  --> src/bin/ref_cells.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cell::RefCell;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::mem`
[INFO] [stdout]  --> src/bin/ref_cells.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::mem;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::rc::Rc`
[INFO] [stdout]  --> src/bin/ref_cells.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::rc::Rc;
[INFO] [stdout]   |     ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::mem`
[INFO] [stdout]    --> src/bin/ref_cells.rs:228:9
[INFO] [stdout]     |
[INFO] [stdout] 228 |     use std::mem;
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `cell_1`
[INFO] [stdout]  --> src/bin/unsafe.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let cell_1 = Cell {
[INFO] [stdout]   |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_cell_1`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]   --> src/bin/unsafe.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 11 |     unsafe {
[INFO] [stdout]    |     ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_unsafe)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `val`
[INFO] [stdout]  --> src/bin/unsafe.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 |     val: i32,
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `next`
[INFO] [stdout]  --> src/bin/unsafe.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 |     next: Option<Box<Cell>>,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `cell_1`
[INFO] [stdout]  --> src/bin/unsafe.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let cell_1 = Cell {
[INFO] [stdout]   |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_cell_1`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]   --> src/bin/unsafe.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 11 |     unsafe {
[INFO] [stdout]    |     ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_unsafe)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `val`
[INFO] [stdout]  --> src/bin/unsafe.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 |     val: i32,
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `next`
[INFO] [stdout]  --> src/bin/unsafe.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 |     next: Option<Box<Cell>>,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 12.38s
[INFO] running `Command { std: "docker" "inspect" "a153fc38191196060b15f56471d1efb7297aa92ca820013b6322f504b480ebe8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a153fc38191196060b15f56471d1efb7297aa92ca820013b6322f504b480ebe8", kill_on_drop: false }`
[INFO] [stdout] a153fc38191196060b15f56471d1efb7297aa92ca820013b6322f504b480ebe8