[INFO] fetching crate driverkit 0.25.0...
[INFO] testing driverkit-0.25.0 against beta-2025-09-21 for beta-1.91-3
[INFO] extracting crate driverkit 0.25.0 into /workspace/builds/worker-2-tc2/source
[INFO] started tweaking crates.io crate driverkit 0.25.0
[INFO] finished tweaking crates.io crate driverkit 0.25.0
[INFO] tweaked toml for crates.io crate driverkit 0.25.0 written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate driverkit 0.25.0 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] crate crates.io crate driverkit 0.25.0 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-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 9131ba037ddbf9b59b8c147fdae29af148f9b8c65b0444b33a0ec0cacbc1e03c
[INFO] running `Command { std: "docker" "start" "-a" "9131ba037ddbf9b59b8c147fdae29af148f9b8c65b0444b33a0ec0cacbc1e03c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9131ba037ddbf9b59b8c147fdae29af148f9b8c65b0444b33a0ec0cacbc1e03c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9131ba037ddbf9b59b8c147fdae29af148f9b8c65b0444b33a0ec0cacbc1e03c", kill_on_drop: false }`
[INFO] [stdout] 9131ba037ddbf9b59b8c147fdae29af148f9b8c65b0444b33a0ec0cacbc1e03c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 1cf184dc93e445aea4506bcad8bc944e45de229e33fc44f198459393e2ae0f16
[INFO] running `Command { std: "docker" "start" "-a" "1cf184dc93e445aea4506bcad8bc944e45de229e33fc44f198459393e2ae0f16", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.139
[INFO] [stderr]    Compiling proc-macro2 v1.0.51
[INFO] [stderr]    Compiling quote v1.0.23
[INFO] [stderr]    Compiling unicode-ident v1.0.6
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling siphasher v0.3.10
[INFO] [stderr]    Compiling ppv-lite86 v0.2.17
[INFO] [stderr]    Compiling once_cell v1.17.1
[INFO] [stderr]    Compiling phf_shared v0.10.0
[INFO] [stderr]    Compiling tracing-core v0.1.30
[INFO] [stderr]    Compiling pin-project-lite v0.2.9
[INFO] [stderr]    Compiling x86 v0.52.0
[INFO] [stderr]    Compiling raw-cpuid v10.7.0
[INFO] [stderr]    Compiling bit_field v0.10.2
[INFO] [stderr]    Compiling phf v0.10.1
[INFO] [stderr]    Compiling memmap2 v0.5.10
[INFO] [stderr]    Compiling custom_error v1.9.2
[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/custom_error-1.9.2/src/lib.rs:3:35
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![cfg_attr(feature = "unstable", feature(allocator_api, try_reserve))]
[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 `custom_error` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "1cf184dc93e445aea4506bcad8bc944e45de229e33fc44f198459393e2ae0f16", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1cf184dc93e445aea4506bcad8bc944e45de229e33fc44f198459393e2ae0f16", kill_on_drop: false }`
[INFO] [stdout] 1cf184dc93e445aea4506bcad8bc944e45de229e33fc44f198459393e2ae0f16