[INFO] fetching crate reflux 6.4.2...
[INFO] testing reflux-6.4.2 against beta-2025-09-21 for beta-1.91-3
[INFO] extracting crate reflux 6.4.2 into /workspace/builds/worker-0-tc2/source
[INFO] started tweaking crates.io crate reflux 6.4.2
[INFO] finished tweaking crates.io crate reflux 6.4.2
[INFO] tweaked toml for crates.io crate reflux 6.4.2 written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate reflux 6.4.2 on toolchain beta-2025-09-21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-09-21" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate reflux 6.4.2 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-2025-09-21" "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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-09-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 499ba6a7b7455fcadc70febbd0c24689eadb6a3b34559b3b014a58fa1a3fd959
[INFO] running `Command { std: "docker" "start" "-a" "499ba6a7b7455fcadc70febbd0c24689eadb6a3b34559b3b014a58fa1a3fd959", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "499ba6a7b7455fcadc70febbd0c24689eadb6a3b34559b3b014a58fa1a3fd959", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "499ba6a7b7455fcadc70febbd0c24689eadb6a3b34559b3b014a58fa1a3fd959", kill_on_drop: false }`
[INFO] [stdout] 499ba6a7b7455fcadc70febbd0c24689eadb6a3b34559b3b014a58fa1a3fd959
[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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-09-21" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 196b9cc530439190ba5860c2a89f7f35c6774703daae774585a7ded4f0c39710
[INFO] running `Command { std: "docker" "start" "-a" "196b9cc530439190ba5860c2a89f7f35c6774703daae774585a7ded4f0c39710", kill_on_drop: false }`
[INFO] [stderr]    Compiling crossbeam-utils v0.8.20
[INFO] [stderr]    Compiling crossbeam-channel v0.5.14
[INFO] [stderr]    Compiling reflux v6.4.2 (/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(coroutines, coroutine_trait, stmt_expr_attributes)]
[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:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(unboxed_closures)]
[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 `reflux` (lib) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "196b9cc530439190ba5860c2a89f7f35c6774703daae774585a7ded4f0c39710", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "196b9cc530439190ba5860c2a89f7f35c6774703daae774585a7ded4f0c39710", kill_on_drop: false }`
[INFO] [stdout] 196b9cc530439190ba5860c2a89f7f35c6774703daae774585a7ded4f0c39710