[INFO] fetching crate fuzzcheck_serializer 0.6.0...
[INFO] testing fuzzcheck_serializer-0.6.0 against beta-2025-09-21 for beta-1.91-3
[INFO] extracting crate fuzzcheck_serializer 0.6.0 into /workspace/builds/worker-5-tc2/source
[INFO] started tweaking crates.io crate fuzzcheck_serializer 0.6.0
[INFO] finished tweaking crates.io crate fuzzcheck_serializer 0.6.0
[INFO] tweaked toml for crates.io crate fuzzcheck_serializer 0.6.0 written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate fuzzcheck_serializer 0.6.0 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] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-09-21" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]      Locking 16 packages to latest compatible versions
[INFO] [stderr]       Adding decent-serde-json-alternative v0.4.0 (available: v0.5.0)
[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-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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] c33f441c4877d75ca27d2144f03862ca4e46f56f5933aca3b2408f75124b5d30
[INFO] running `Command { std: "docker" "start" "-a" "c33f441c4877d75ca27d2144f03862ca4e46f56f5933aca3b2408f75124b5d30", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c33f441c4877d75ca27d2144f03862ca4e46f56f5933aca3b2408f75124b5d30", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c33f441c4877d75ca27d2144f03862ca4e46f56f5933aca3b2408f75124b5d30", kill_on_drop: false }`
[INFO] [stdout] c33f441c4877d75ca27d2144f03862ca4e46f56f5933aca3b2408f75124b5d30
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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] 3fb8c739aa96d6fc9e542267b0abf071c8efabc2fdc104109fd9c90c32c39c9c
[INFO] running `Command { std: "docker" "start" "-a" "3fb8c739aa96d6fc9e542267b0abf071c8efabc2fdc104109fd9c90c32c39c9c", kill_on_drop: false }`
[INFO] [stderr]    Compiling fuzzcheck_traits v0.6.0
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/fuzzcheck_traits-0.6.0/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(arc_new_cyclic)]
[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 `fuzzcheck_traits` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "3fb8c739aa96d6fc9e542267b0abf071c8efabc2fdc104109fd9c90c32c39c9c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3fb8c739aa96d6fc9e542267b0abf071c8efabc2fdc104109fd9c90c32c39c9c", kill_on_drop: false }`
[INFO] [stdout] 3fb8c739aa96d6fc9e542267b0abf071c8efabc2fdc104109fd9c90c32c39c9c