[INFO] fetching crate rustc-ap-rustc_span 727.0.0...
[INFO] testing rustc-ap-rustc_span-727.0.0 against beta-2025-09-21 for beta-1.91-3
[INFO] extracting crate rustc-ap-rustc_span 727.0.0 into /workspace/builds/worker-4-tc2/source
[INFO] started tweaking crates.io crate rustc-ap-rustc_span 727.0.0
[INFO] finished tweaking crates.io crate rustc-ap-rustc_span 727.0.0
[INFO] tweaked toml for crates.io crate rustc-ap-rustc_span 727.0.0 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate rustc-ap-rustc_span 727.0.0 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]     Blocking waiting for file lock on package cache
[INFO] [stderr]      Locking 93 packages to latest compatible versions
[INFO] [stderr]       Adding cfg-if v0.1.10 (available: v1.0.3)
[INFO] [stderr]       Adding md-5 v0.9.1 (available: v0.10.6)
[INFO] [stderr]       Adding sha-1 v0.9.8 (available: v0.10.1)
[INFO] [stderr]       Adding sha2 v0.9.9 (available: v0.10.9)
[INFO] [stderr]       Adding unicode-width v0.1.14 (available: v0.2.1)
[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-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] 60d93cf8b8d8b07c27a730d6352d4f0b804bd20c85b8c0d5b90daeb05d555164
[INFO] running `Command { std: "docker" "start" "-a" "60d93cf8b8d8b07c27a730d6352d4f0b804bd20c85b8c0d5b90daeb05d555164", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "60d93cf8b8d8b07c27a730d6352d4f0b804bd20c85b8c0d5b90daeb05d555164", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "60d93cf8b8d8b07c27a730d6352d4f0b804bd20c85b8c0d5b90daeb05d555164", kill_on_drop: false }`
[INFO] [stdout] 60d93cf8b8d8b07c27a730d6352d4f0b804bd20c85b8c0d5b90daeb05d555164
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] 03843e6b5478a0a7ae3943a444181bcab386246f97001611c8d7505dfb3f0038
[INFO] running `Command { std: "docker" "start" "-a" "03843e6b5478a0a7ae3943a444181bcab386246f97001611c8d7505dfb3f0038", kill_on_drop: false }`
[INFO] [stderr]    Compiling crossbeam-utils v0.8.21
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling smallvec v1.15.1
[INFO] [stderr]    Compiling parking_lot_core v0.8.6
[INFO] [stderr]    Compiling unicode-xid v0.2.6
[INFO] [stderr]    Compiling cc v1.2.39
[INFO] [stderr]    Compiling indexmap v1.9.3
[INFO] [stderr]    Compiling lock_api v0.4.13
[INFO] [stderr]    Compiling instant v0.1.13
[INFO] [stderr]    Compiling hashbrown v0.12.3
[INFO] [stderr]    Compiling scopeguard v1.2.0
[INFO] [stderr]    Compiling getrandom v0.3.3
[INFO] [stderr]    Compiling rustc-rayon-core v0.3.2
[INFO] [stderr]    Compiling syn v2.0.106
[INFO] [stderr]    Compiling num_cpus v1.17.0
[INFO] [stderr]    Compiling perf-event-open-sys v1.0.1
[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/smallvec-1.15.1/src/lib.rs:96:37
[INFO] [stdout]    |
[INFO] [stdout] 96 | #![cfg_attr(feature = "may_dangle", feature(dropck_eyepatch))]
[INFO] [stdout]    |                                     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling memmap2 v0.2.3
[INFO] [stderr]    Compiling rustc-hash v1.1.0
[INFO] [stderr]    Compiling either v1.15.0
[INFO] [stderr]    Compiling arrayvec v0.7.6
[INFO] [stderr]    Compiling ena v0.14.3
[INFO] [stderr]    Compiling jobserver v0.1.34
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `smallvec` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "03843e6b5478a0a7ae3943a444181bcab386246f97001611c8d7505dfb3f0038", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "03843e6b5478a0a7ae3943a444181bcab386246f97001611c8d7505dfb3f0038", kill_on_drop: false }`
[INFO] [stdout] 03843e6b5478a0a7ae3943a444181bcab386246f97001611c8d7505dfb3f0038