[INFO] fetching crate flowfairy_api 0.2.2...
[INFO] testing flowfairy_api-0.2.2 against beta-2025-09-21 for beta-1.91-3
[INFO] extracting crate flowfairy_api 0.2.2 into /workspace/builds/worker-5-tc2/source
[INFO] started tweaking crates.io crate flowfairy_api 0.2.2
[INFO] finished tweaking crates.io crate flowfairy_api 0.2.2
[INFO] tweaked toml for crates.io crate flowfairy_api 0.2.2 written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate flowfairy_api 0.2.2 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] 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]     Updating crates.io index
[INFO] [stderr]      Locking 18 packages to latest compatible versions
[INFO] [stderr]       Adding thiserror v1.0.69 (available: v2.0.17)
[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] [stderr]     Blocking waiting for file lock on package cache
[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] 11d2a4a9aceaf3028c9d0d715e883dd4722ebf752d49ea22eb05022c79506ac8
[INFO] running `Command { std: "docker" "start" "-a" "11d2a4a9aceaf3028c9d0d715e883dd4722ebf752d49ea22eb05022c79506ac8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "11d2a4a9aceaf3028c9d0d715e883dd4722ebf752d49ea22eb05022c79506ac8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "11d2a4a9aceaf3028c9d0d715e883dd4722ebf752d49ea22eb05022c79506ac8", kill_on_drop: false }`
[INFO] [stdout] 11d2a4a9aceaf3028c9d0d715e883dd4722ebf752d49ea22eb05022c79506ac8
[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] a8ce3ded85b581d063294e5ca75c1c27a4508db4d7924965f4903ecd5631585c
[INFO] running `Command { std: "docker" "start" "-a" "a8ce3ded85b581d063294e5ca75c1c27a4508db4d7924965f4903ecd5631585c", kill_on_drop: false }`
[INFO] [stderr]    Compiling aho-corasick v1.1.3
[INFO] [stderr]    Compiling serde_derive v1.0.228
[INFO] [stderr]    Compiling regex-automata v0.4.11
[INFO] [stderr]    Compiling serde v1.0.228
[INFO] [stderr]    Compiling regex v1.11.3
[INFO] [stderr]    Compiling flowfairy_api v0.2.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:36:1
[INFO] [stdout]    |
[INFO] [stdout] 36 | #![feature(byte_slice_trim_ascii)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `byte_slice_trim_ascii` has been stable since 1.80.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:36:12
[INFO] [stdout]    |
[INFO] [stdout] 36 | #![feature(byte_slice_trim_ascii)]
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `events` is never read
[INFO] [stdout]    --> src/fcs.rs:228:13
[INFO] [stdout]     |
[INFO] [stdout] 228 |     let mut events = Vec::with_capacity(n_events);
[INFO] [stdout]     |             ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `flowfairy_api` (lib) due to 1 previous error; 2 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "a8ce3ded85b581d063294e5ca75c1c27a4508db4d7924965f4903ecd5631585c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a8ce3ded85b581d063294e5ca75c1c27a4508db4d7924965f4903ecd5631585c", kill_on_drop: false }`
[INFO] [stdout] a8ce3ded85b581d063294e5ca75c1c27a4508db4d7924965f4903ecd5631585c