[INFO] fetching crate prefixes 0.1.0...
[INFO] testing prefixes-0.1.0 against beta-2026-04-21 for beta-1.96-2
[INFO] extracting crate prefixes 0.1.0 into /workspace/builds/worker-6-tc2/source
[INFO] started tweaking crates.io crate prefixes 0.1.0
[INFO] finished tweaking crates.io crate prefixes 0.1.0
[INFO] tweaked toml for crates.io crate prefixes 0.1.0 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate prefixes 0.1.0 on toolchain beta-2026-04-21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "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-2026-04-21" "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] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 85d1b41d6bec0c72abfb278ec35a8c56407e53f0c22702416f6cdb9491c84262
[INFO] running `Command { std: "docker" "start" "-a" "85d1b41d6bec0c72abfb278ec35a8c56407e53f0c22702416f6cdb9491c84262", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "85d1b41d6bec0c72abfb278ec35a8c56407e53f0c22702416f6cdb9491c84262", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "85d1b41d6bec0c72abfb278ec35a8c56407e53f0c22702416f6cdb9491c84262", kill_on_drop: false }`
[INFO] [stdout] 85d1b41d6bec0c72abfb278ec35a8c56407e53f0c22702416f6cdb9491c84262
[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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 61e113c24f1ec88cc30a0dd00ecf9034bbe7fc71414bcf26ee3f885148916405
[INFO] running `Command { std: "docker" "start" "-a" "61e113c24f1ec88cc30a0dd00ecf9034bbe7fc71414bcf26ee3f885148916405", kill_on_drop: false }`
[INFO] [stderr]    Compiling quote v1.0.45
[INFO] [stderr]    Compiling syn v2.0.117
[INFO] [stderr]    Compiling prefixes-uppercase-os v0.1.0
[INFO] [stderr]    Compiling prefixes-uppercase-p v0.1.0
[INFO] [stderr]    Compiling prefixes-p v0.1.0
[INFO] [stderr]    Compiling prefixes-re v0.1.0
[INFO] [stderr]    Compiling prefixes-uppercase-re v0.1.0
[INFO] [stderr]    Compiling prefixes-s v0.1.0
[INFO] [stderr]    Compiling prefixes-f v0.1.0
[INFO] [stderr]    Compiling prefixes-os v0.1.0
[INFO] [stderr]    Compiling prefixes-ms v0.1.0
[INFO] [stderr]    Compiling prefixes v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(proc_macro_hygiene)]
[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 `prefixes` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "61e113c24f1ec88cc30a0dd00ecf9034bbe7fc71414bcf26ee3f885148916405", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "61e113c24f1ec88cc30a0dd00ecf9034bbe7fc71414bcf26ee3f885148916405", kill_on_drop: false }`
[INFO] [stdout] 61e113c24f1ec88cc30a0dd00ecf9034bbe7fc71414bcf26ee3f885148916405
