[INFO] fetching crate optimal-core 0.0.0...
[INFO] testing optimal-core-0.0.0 against beta-2025-10-28 for beta-1.92-2
[INFO] extracting crate optimal-core 0.0.0 into /workspace/builds/worker-3-tc2/source
[INFO] started tweaking crates.io crate optimal-core 0.0.0
[INFO] finished tweaking crates.io crate optimal-core 0.0.0
[INFO] tweaked toml for crates.io crate optimal-core 0.0.0 written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate optimal-core 0.0.0 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 16 packages to latest compatible versions
[INFO] [stderr]       Adding blanket v0.3.0 (available: v0.4.0)
[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] 602be12aebcf7655034419a4c56fe3e5fc8bb9e5ac866e24fe369c78a71c0256
[INFO] running `Command { std: "docker" "start" "-a" "602be12aebcf7655034419a4c56fe3e5fc8bb9e5ac866e24fe369c78a71c0256", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "602be12aebcf7655034419a4c56fe3e5fc8bb9e5ac866e24fe369c78a71c0256", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "602be12aebcf7655034419a4c56fe3e5fc8bb9e5ac866e24fe369c78a71c0256", kill_on_drop: false }`
[INFO] [stdout] 602be12aebcf7655034419a4c56fe3e5fc8bb9e5ac866e24fe369c78a71c0256
[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] bf1c9b5ad835a0e475d90ffff4db52064fca15fb1b6d50da630d505815d0c473
[INFO] running `Command { std: "docker" "start" "-a" "bf1c9b5ad835a0e475d90ffff4db52064fca15fb1b6d50da630d505815d0c473", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v2.0.108
[INFO] [stderr]    Compiling streaming-iterator v0.1.9
[INFO] [stderr]    Compiling blanket v0.3.0
[INFO] [stderr]    Compiling optimal-core v0.0.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 4.82s
[INFO] running `Command { std: "docker" "inspect" "bf1c9b5ad835a0e475d90ffff4db52064fca15fb1b6d50da630d505815d0c473", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bf1c9b5ad835a0e475d90ffff4db52064fca15fb1b6d50da630d505815d0c473", kill_on_drop: false }`
[INFO] [stdout] bf1c9b5ad835a0e475d90ffff4db52064fca15fb1b6d50da630d505815d0c473
[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" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1c0d3f32888594ec3a4418fee2211bd256b178afeec26fee84e20d566c3236f0
[INFO] running `Command { std: "docker" "start" "-a" "1c0d3f32888594ec3a4418fee2211bd256b178afeec26fee84e20d566c3236f0", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v2.0.108
[INFO] [stderr]    Compiling replace_with v0.1.8
[INFO] [stderr]    Compiling serde_derive v1.0.228
[INFO] [stderr]    Compiling blanket v0.3.0
[INFO] [stderr]    Compiling optimal-core v0.0.0 (/opt/rustwide/workdir)
[INFO] [stderr]    Compiling serde v1.0.228
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:2:19
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![cfg_attr(test, feature(unboxed_closures))]
[INFO] [stdout]   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:3:19
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![cfg_attr(test, feature(fn_traits))]
[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 `optimal-core` (lib test) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "1c0d3f32888594ec3a4418fee2211bd256b178afeec26fee84e20d566c3236f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1c0d3f32888594ec3a4418fee2211bd256b178afeec26fee84e20d566c3236f0", kill_on_drop: false }`
[INFO] [stdout] 1c0d3f32888594ec3a4418fee2211bd256b178afeec26fee84e20d566c3236f0