[INFO] cloning repository https://github.com/matklad/group-by-challenge
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/matklad/group-by-challenge" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmatklad%2Fgroup-by-challenge", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmatklad%2Fgroup-by-challenge'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 297c95d461427a61f621767443897c37bef43f0f
[INFO] checking matklad/group-by-challenge against master#936f2600b6c903b04387f74ed5cbce88bb06d243 for pr-91141
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmatklad%2Fgroup-by-challenge" "/workspace/builds/worker-41/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-41/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/matklad/group-by-challenge on toolchain 936f2600b6c903b04387f74ed5cbce88bb06d243
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/matklad/group-by-challenge
[INFO] finished tweaking git repo https://github.com/matklad/group-by-challenge
[INFO] tweaked toml for git repo https://github.com/matklad/group-by-challenge written to /workspace/builds/worker-41/source/Cargo.toml
[INFO] crate git repo https://github.com/matklad/group-by-challenge already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-41/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-41/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] afdc99c1155c71d0fb2f87990fc6d2a8eb6f1d085c74ce7cee4a0a9dfffe4101
[INFO] running `Command { std: "docker" "start" "-a" "afdc99c1155c71d0fb2f87990fc6d2a8eb6f1d085c74ce7cee4a0a9dfffe4101", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "afdc99c1155c71d0fb2f87990fc6d2a8eb6f1d085c74ce7cee4a0a9dfffe4101", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "afdc99c1155c71d0fb2f87990fc6d2a8eb6f1d085c74ce7cee4a0a9dfffe4101", kill_on_drop: false }`
[INFO] [stdout] afdc99c1155c71d0fb2f87990fc6d2a8eb6f1d085c74ce7cee4a0a9dfffe4101
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-41/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-41/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e73b216efa1be46127e37f670543d2b2ff3473eebfce85dfb733cb6fb3e9b099
[INFO] running `Command { std: "docker" "start" "-a" "e73b216efa1be46127e37f670543d2b2ff3473eebfce85dfb733cb6fb3e9b099", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking group-by-challenge v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `xs`
[INFO] [stdout]  --> src/lib.rs:1:29
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn group_by<I, F, K, T>(xs: I, key_fn: F) -> Vec<(K, Vec<T>)>
[INFO] [stdout]   |                             ^^ help: if this is intentional, prefix it with an underscore: `_xs`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `key_fn`
[INFO] [stdout]  --> src/lib.rs:1:36
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn group_by<I, F, K, T>(xs: I, key_fn: F) -> Vec<(K, Vec<T>)>
[INFO] [stdout]   |                                    ^^^^^^ help: if this is intentional, prefix it with an underscore: `_key_fn`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `xs`
[INFO] [stdout]  --> src/lib.rs:1:29
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn group_by<I, F, K, T>(xs: I, key_fn: F) -> Vec<(K, Vec<T>)>
[INFO] [stdout]   |                             ^^ help: if this is intentional, prefix it with an underscore: `_xs`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `key_fn`
[INFO] [stdout]  --> src/lib.rs:1:36
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn group_by<I, F, K, T>(xs: I, key_fn: F) -> Vec<(K, Vec<T>)>
[INFO] [stdout]   |                                    ^^^^^^ help: if this is intentional, prefix it with an underscore: `_key_fn`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.54s
[INFO] running `Command { std: "docker" "inspect" "e73b216efa1be46127e37f670543d2b2ff3473eebfce85dfb733cb6fb3e9b099", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e73b216efa1be46127e37f670543d2b2ff3473eebfce85dfb733cb6fb3e9b099", kill_on_drop: false }`
[INFO] [stdout] e73b216efa1be46127e37f670543d2b2ff3473eebfce85dfb733cb6fb3e9b099