[INFO] fetching crate ranked-pairs 0.0.2-beta...
[INFO] testing ranked-pairs-0.0.2-beta against beta-2025-10-28 for beta-1.92-2
[INFO] extracting crate ranked-pairs 0.0.2-beta into /workspace/builds/worker-0-tc2/source
[INFO] started tweaking crates.io crate ranked-pairs 0.0.2-beta
[INFO] finished tweaking crates.io crate ranked-pairs 0.0.2-beta
[INFO] tweaked toml for crates.io crate ranked-pairs 0.0.2-beta written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate ranked-pairs 0.0.2-beta on toolchain beta-2025-10-28
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-10-28" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate ranked-pairs 0.0.2-beta 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-2025-10-28" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-10-28" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b9d2b00bc92ed5d53f8ecf87f423fa14a89873a6e5cdb137d3dffa39c0f487be
[INFO] running `Command { std: "docker" "start" "-a" "b9d2b00bc92ed5d53f8ecf87f423fa14a89873a6e5cdb137d3dffa39c0f487be", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b9d2b00bc92ed5d53f8ecf87f423fa14a89873a6e5cdb137d3dffa39c0f487be", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b9d2b00bc92ed5d53f8ecf87f423fa14a89873a6e5cdb137d3dffa39c0f487be", kill_on_drop: false }`
[INFO] [stdout] b9d2b00bc92ed5d53f8ecf87f423fa14a89873a6e5cdb137d3dffa39c0f487be
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-10-28" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 04268c7cda808a19572ca5466b33996efabce6f703011e87e2a29fc403000a58
[INFO] running `Command { std: "docker" "start" "-a" "04268c7cda808a19572ca5466b33996efabce6f703011e87e2a29fc403000a58", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.101
[INFO] [stderr]    Compiling thiserror v2.0.16
[INFO] [stderr]    Compiling either v1.15.0
[INFO] [stderr]    Compiling rangemap v1.6.0
[INFO] [stderr]    Compiling itertools v0.14.0
[INFO] [stderr]    Compiling quote v1.0.40
[INFO] [stderr]    Compiling syn v2.0.106
[INFO] [stderr]    Compiling thiserror-impl v2.0.16
[INFO] [stderr]    Compiling ranked-pairs v0.0.2-beta (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(btree_cursors)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `ranked-pairs` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "04268c7cda808a19572ca5466b33996efabce6f703011e87e2a29fc403000a58", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "04268c7cda808a19572ca5466b33996efabce6f703011e87e2a29fc403000a58", kill_on_drop: false }`
[INFO] [stdout] 04268c7cda808a19572ca5466b33996efabce6f703011e87e2a29fc403000a58