[INFO] cloning repository https://github.com/xeusteerapat/iterator-practice
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/xeusteerapat/iterator-practice" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxeusteerapat%2Fiterator-practice", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxeusteerapat%2Fiterator-practice'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ea5e9334f031a81f6f9cfa5da164f7476b6ef9a8
[INFO] checking xeusteerapat/iterator-practice against master#b2728d5426bab1d8c39709768c7e22b7f66dde5d for pr-135852
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxeusteerapat%2Fiterator-practice" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/xeusteerapat/iterator-practice on toolchain b2728d5426bab1d8c39709768c7e22b7f66dde5d
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b2728d5426bab1d8c39709768c7e22b7f66dde5d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/xeusteerapat/iterator-practice
[INFO] finished tweaking git repo https://github.com/xeusteerapat/iterator-practice
[INFO] tweaked toml for git repo https://github.com/xeusteerapat/iterator-practice written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/xeusteerapat/iterator-practice 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" "+b2728d5426bab1d8c39709768c7e22b7f66dde5d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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:c80049f3b88b82089a44e0f06d0d6029d44b96b7257e55a1cd63dbc9f4c33334" "/opt/rustwide/cargo-home/bin/cargo" "+b2728d5426bab1d8c39709768c7e22b7f66dde5d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1cac3ba7e744616e07165551c9b818828a4461008f060d437bb4909b25323cb9
[INFO] running `Command { std: "docker" "start" "-a" "1cac3ba7e744616e07165551c9b818828a4461008f060d437bb4909b25323cb9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1cac3ba7e744616e07165551c9b818828a4461008f060d437bb4909b25323cb9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1cac3ba7e744616e07165551c9b818828a4461008f060d437bb4909b25323cb9", kill_on_drop: false }`
[INFO] [stdout] 1cac3ba7e744616e07165551c9b818828a4461008f060d437bb4909b25323cb9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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:c80049f3b88b82089a44e0f06d0d6029d44b96b7257e55a1cd63dbc9f4c33334" "/opt/rustwide/cargo-home/bin/cargo" "+b2728d5426bab1d8c39709768c7e22b7f66dde5d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 965919e52da38fa41cad07b2f18c49ec294741c1725d322a979c96ce5097d309
[INFO] running `Command { std: "docker" "start" "-a" "965919e52da38fa41cad07b2f18c49ec294741c1725d322a979c96ce5097d309", kill_on_drop: false }`
[INFO] [stderr]     Checking iterator-practice v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let mut colors = vec![
[INFO] [stdout]    |         ----^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `print_element` is never used
[INFO] [stdout]  --> src/main.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn print_element(elements: &[String]) {
[INFO] [stdout]   |    ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `shorten_strings` is never used
[INFO] [stdout]   --> src/main.rs:16:4
[INFO] [stdout]    |
[INFO] [stdout] 16 | fn shorten_strings(elements: &mut [String]) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `to_uppercase` is never used
[INFO] [stdout]   --> src/main.rs:21:4
[INFO] [stdout]    |
[INFO] [stdout] 21 | fn to_uppercase(elements: &[String]) -> Vec<String> {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `move_elements` is never used
[INFO] [stdout]   --> src/main.rs:32:4
[INFO] [stdout]    |
[INFO] [stdout] 32 | fn move_elements(vec_a: Vec<String>, vec_b: &mut Vec<String>) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `explode` is never used
[INFO] [stdout]   --> src/main.rs:36:4
[INFO] [stdout]    |
[INFO] [stdout] 36 | fn explode(elements: &[String]) -> Vec<Vec<String>> {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let mut colors = vec![
[INFO] [stdout]    |         ----^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `print_element` is never used
[INFO] [stdout]  --> src/main.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn print_element(elements: &[String]) {
[INFO] [stdout]   |    ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `shorten_strings` is never used
[INFO] [stdout]   --> src/main.rs:16:4
[INFO] [stdout]    |
[INFO] [stdout] 16 | fn shorten_strings(elements: &mut [String]) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `to_uppercase` is never used
[INFO] [stdout]   --> src/main.rs:21:4
[INFO] [stdout]    |
[INFO] [stdout] 21 | fn to_uppercase(elements: &[String]) -> Vec<String> {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `move_elements` is never used
[INFO] [stdout]   --> src/main.rs:32:4
[INFO] [stdout]    |
[INFO] [stdout] 32 | fn move_elements(vec_a: Vec<String>, vec_b: &mut Vec<String>) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `explode` is never used
[INFO] [stdout]   --> src/main.rs:36:4
[INFO] [stdout]    |
[INFO] [stdout] 36 | fn explode(elements: &[String]) -> Vec<Vec<String>> {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.07s
[INFO] running `Command { std: "docker" "inspect" "965919e52da38fa41cad07b2f18c49ec294741c1725d322a979c96ce5097d309", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "965919e52da38fa41cad07b2f18c49ec294741c1725d322a979c96ce5097d309", kill_on_drop: false }`
[INFO] [stdout] 965919e52da38fa41cad07b2f18c49ec294741c1725d322a979c96ce5097d309