[INFO] fetching crate prefix-varint 0.0.1-alpha.6...
[INFO] testing prefix-varint-0.0.1-alpha.6 against beta-2025-10-28 for beta-1.92-2
[INFO] extracting crate prefix-varint 0.0.1-alpha.6 into /workspace/builds/worker-3-tc2/source
[INFO] started tweaking crates.io crate prefix-varint 0.0.1-alpha.6
[INFO] finished tweaking crates.io crate prefix-varint 0.0.1-alpha.6
[INFO] tweaked toml for crates.io crate prefix-varint 0.0.1-alpha.6 written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate prefix-varint 0.0.1-alpha.6 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] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-10-28" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 70 packages to latest compatible versions
[INFO] [stderr]       Adding criterion v0.3.6 (available: v0.7.0)
[INFO] [stderr]       Adding rand v0.8.5 (available: v0.9.2)
[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-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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] ad9b0ca6f95ccc9ed0b85a6c6c231f3de1086b50969e9a3af9307c1b7157f15f
[INFO] running `Command { std: "docker" "start" "-a" "ad9b0ca6f95ccc9ed0b85a6c6c231f3de1086b50969e9a3af9307c1b7157f15f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ad9b0ca6f95ccc9ed0b85a6c6c231f3de1086b50969e9a3af9307c1b7157f15f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ad9b0ca6f95ccc9ed0b85a6c6c231f3de1086b50969e9a3af9307c1b7157f15f", kill_on_drop: false }`
[INFO] [stdout] ad9b0ca6f95ccc9ed0b85a6c6c231f3de1086b50969e9a3af9307c1b7157f15f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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] c995dcadd167609a20347c0cd10c3c201d4f98ad5138d61dc6951ed0bfa83e01
[INFO] running `Command { std: "docker" "start" "-a" "c995dcadd167609a20347c0cd10c3c201d4f98ad5138d61dc6951ed0bfa83e01", kill_on_drop: false }`
[INFO] [stderr]    Compiling prefix-varint v0.0.1-alpha.6 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(cursor_remaining)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `cursor_remaining`
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(cursor_remaining)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0635.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `prefix-varint` (lib) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "c995dcadd167609a20347c0cd10c3c201d4f98ad5138d61dc6951ed0bfa83e01", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c995dcadd167609a20347c0cd10c3c201d4f98ad5138d61dc6951ed0bfa83e01", kill_on_drop: false }`
[INFO] [stdout] c995dcadd167609a20347c0cd10c3c201d4f98ad5138d61dc6951ed0bfa83e01