[INFO] fetching crate iterator_item 0.2.0...
[INFO] testing iterator_item-0.2.0 against beta-2025-09-21 for beta-1.91-3
[INFO] extracting crate iterator_item 0.2.0 into /workspace/builds/worker-6-tc2/source
[INFO] started tweaking crates.io crate iterator_item 0.2.0
[INFO] finished tweaking crates.io crate iterator_item 0.2.0
[INFO] tweaked toml for crates.io crate iterator_item 0.2.0 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate iterator_item 0.2.0 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]     Updating crates.io index
[INFO] [stderr]      Locking 45 packages to latest compatible versions
[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-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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] 7f2fb18e440a1703c90df929570658af727318209f1ddffa43efbfe4c2df1e1c
[INFO] running `Command { std: "docker" "start" "-a" "7f2fb18e440a1703c90df929570658af727318209f1ddffa43efbfe4c2df1e1c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7f2fb18e440a1703c90df929570658af727318209f1ddffa43efbfe4c2df1e1c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7f2fb18e440a1703c90df929570658af727318209f1ddffa43efbfe4c2df1e1c", kill_on_drop: false }`
[INFO] [stdout] 7f2fb18e440a1703c90df929570658af727318209f1ddffa43efbfe4c2df1e1c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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] 8461e40b0f04dd43bb656ad6bc26a05fa576a7eaba38aae5ce4fdd80bef53f0e
[INFO] running `Command { std: "docker" "start" "-a" "8461e40b0f04dd43bb656ad6bc26a05fa576a7eaba38aae5ce4fdd80bef53f0e", kill_on_drop: false }`
[INFO] [stderr]    Compiling futures-sink v0.3.31
[INFO] [stderr]    Compiling memchr v2.7.6
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling futures-io v0.3.31
[INFO] [stderr]    Compiling syn v2.0.106
[INFO] [stderr]    Compiling futures-channel v0.3.31
[INFO] [stderr]    Compiling futures-macro v0.3.31
[INFO] [stderr]    Compiling futures-util v0.3.31
[INFO] [stderr]    Compiling iterator_item_macros v0.1.0
[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/iterator_item_macros-0.1.0/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(proc_macro_diagnostic)]
[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 `iterator_item_macros` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "8461e40b0f04dd43bb656ad6bc26a05fa576a7eaba38aae5ce4fdd80bef53f0e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8461e40b0f04dd43bb656ad6bc26a05fa576a7eaba38aae5ce4fdd80bef53f0e", kill_on_drop: false }`
[INFO] [stdout] 8461e40b0f04dd43bb656ad6bc26a05fa576a7eaba38aae5ce4fdd80bef53f0e