[INFO] fetching crate sliding_windows 3.0.1...
[INFO] testing sliding_windows-3.0.1 against beta-2026-04-21 for beta-1.96-2
[INFO] extracting crate sliding_windows 3.0.1 into /workspace/builds/worker-6-tc2/source
[INFO] started tweaking crates.io crate sliding_windows 3.0.1
[INFO] finished tweaking crates.io crate sliding_windows 3.0.1
[INFO] tweaked toml for crates.io crate sliding_windows 3.0.1 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate sliding_windows 3.0.1 on toolchain beta-2026-04-21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate sliding_windows 3.0.1 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" "+beta-2026-04-21" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: `package.edition` is unspecified, defaulting to `2015` while the latest is `2024`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "+beta-2026-04-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4553fb5851195c1c9384baba129e07fb5ed7887063fc4bf8e9a6726554c9fd8a
[INFO] running `Command { std: "docker" "start" "-a" "4553fb5851195c1c9384baba129e07fb5ed7887063fc4bf8e9a6726554c9fd8a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4553fb5851195c1c9384baba129e07fb5ed7887063fc4bf8e9a6726554c9fd8a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4553fb5851195c1c9384baba129e07fb5ed7887063fc4bf8e9a6726554c9fd8a", kill_on_drop: false }`
[INFO] [stdout] 4553fb5851195c1c9384baba129e07fb5ed7887063fc4bf8e9a6726554c9fd8a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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" "+beta-2026-04-21" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 78337b153094f4db32b3d28c9d74b762fc4713d086b3047940061a7d1f800e3e
[INFO] running `Command { std: "docker" "start" "-a" "78337b153094f4db32b3d28c9d74b762fc4713d086b3047940061a7d1f800e3e", kill_on_drop: false }`
[INFO] [stderr] warning: `package.edition` is unspecified, defaulting to `2015` while the latest is `2024`
[INFO] [stderr]    Compiling sliding_windows v3.0.1 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.16s
[INFO] running `Command { std: "docker" "inspect" "78337b153094f4db32b3d28c9d74b762fc4713d086b3047940061a7d1f800e3e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "78337b153094f4db32b3d28c9d74b762fc4713d086b3047940061a7d1f800e3e", kill_on_drop: false }`
[INFO] [stdout] 78337b153094f4db32b3d28c9d74b762fc4713d086b3047940061a7d1f800e3e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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" "+beta-2026-04-21" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8d9370e620b3d69d58646ef7bc38c7cf782a50e8d0c6421b14cfe88820e9a5e8
[INFO] running `Command { std: "docker" "start" "-a" "8d9370e620b3d69d58646ef7bc38c7cf782a50e8d0c6421b14cfe88820e9a5e8", kill_on_drop: false }`
[INFO] [stderr] warning: `package.edition` is unspecified, defaulting to `2015` while the latest is `2024`
[INFO] [stderr]    Compiling sliding_windows v3.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:88:19
[INFO] [stdout]    |
[INFO] [stdout] 88 | #![cfg_attr(test, feature(test))]
[INFO] [stdout]    |                   ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tests.rs:37:13
[INFO] [stdout]    |
[INFO] [stdout] 37 |         let mut element_1 = iter_mut.next().unwrap();
[INFO] [stdout]    |             ----^^^^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `sliding_windows` (lib test) due to 1 previous error; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "8d9370e620b3d69d58646ef7bc38c7cf782a50e8d0c6421b14cfe88820e9a5e8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8d9370e620b3d69d58646ef7bc38c7cf782a50e8d0c6421b14cfe88820e9a5e8", kill_on_drop: false }`
[INFO] [stdout] 8d9370e620b3d69d58646ef7bc38c7cf782a50e8d0c6421b14cfe88820e9a5e8
