[INFO] fetching crate ringboard 0.15.0...
[INFO] testing ringboard-0.15.0 against beta-2026-04-21 for beta-1.96-2
[INFO] extracting crate ringboard 0.15.0 into /workspace/builds/worker-4-tc2/source
[INFO] started tweaking crates.io crate ringboard 0.15.0
[INFO] finished tweaking crates.io crate ringboard 0.15.0
[INFO] tweaked toml for crates.io crate ringboard 0.15.0 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate ringboard 0.15.0 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] crate crates.io crate ringboard 0.15.0 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-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-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] fd1ae5f46f5325db3beebf96295092bebc5aab90b2d85d2ffac4137c5b95b604
[INFO] running `Command { std: "docker" "start" "-a" "fd1ae5f46f5325db3beebf96295092bebc5aab90b2d85d2ffac4137c5b95b604", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fd1ae5f46f5325db3beebf96295092bebc5aab90b2d85d2ffac4137c5b95b604", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fd1ae5f46f5325db3beebf96295092bebc5aab90b2d85d2ffac4137c5b95b604", kill_on_drop: false }`
[INFO] [stdout] fd1ae5f46f5325db3beebf96295092bebc5aab90b2d85d2ffac4137c5b95b604
[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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bfd404c4bfcef0411d93ba10043d1ed55a53cba1fa66639f2bf49b796d4c9a71
[INFO] running `Command { std: "docker" "start" "-a" "bfd404c4bfcef0411d93ba10043d1ed55a53cba1fa66639f2bf49b796d4c9a71", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v2.0.117
[INFO] [stderr]    Compiling strsim v0.11.1
[INFO] [stderr]    Compiling rustix v1.1.4
[INFO] [stderr]    Compiling serde v1.0.228
[INFO] [stderr]    Compiling linux-raw-sys v0.12.1
[INFO] [stderr]    Compiling semver v1.0.28
[INFO] [stderr]    Compiling libc v0.2.184
[INFO] [stderr]    Compiling memchr v2.8.0
[INFO] [stderr]    Compiling ident_case v1.0.1
[INFO] [stderr]    Compiling prettyplease v0.2.37
[INFO] [stderr]    Compiling libm v0.2.16
[INFO] [stderr]    Compiling crossbeam-utils v0.8.21
[INFO] [stderr]    Compiling thiserror v2.0.18
[INFO] [stderr]    Compiling rustversion v1.0.22
[INFO] [stderr]    Compiling num-traits v0.2.19
[INFO] [stderr]    Compiling utf8parse v0.2.2
[INFO] [stderr]    Compiling paste v1.0.15
[INFO] [stderr]    Compiling option-ext v0.2.0
[INFO] [stderr]    Compiling anstyle-parse v1.0.0
[INFO] [stderr]    Compiling colorchoice v1.0.5
[INFO] [stderr]    Compiling unicase v2.9.0
[INFO] [stderr]    Compiling anstyle v1.0.14
[INFO] [stderr]    Compiling rustc_version v0.4.1
[INFO] [stderr]    Compiling rand_core v0.10.0
[INFO] [stderr]    Compiling is_terminal_polyfill v1.70.2
[INFO] [stderr]    Compiling anstyle-query v1.1.5
[INFO] [stderr]    Compiling clap_lex v1.1.0
[INFO] [stderr]    Compiling heck v0.5.0
[INFO] [stderr]    Compiling rand v0.10.1
[INFO] [stderr]    Compiling anstream v1.0.0
[INFO] [stderr]    Compiling mime_guess v2.0.5
[INFO] [stderr]    Compiling serde_spanned v1.1.1
[INFO] [stderr]    Compiling toml_datetime v1.1.1+spec-1.1.0
[INFO] [stderr]    Compiling once_cell v1.21.4
[INFO] [stderr]    Compiling mime v0.3.17
[INFO] [stderr]    Compiling rustc-hash v2.1.2
[INFO] [stderr]    Compiling smallvec v2.0.0-alpha.12
[INFO] [stderr]    Compiling toml_writer v1.1.1+spec-1.1.0
[INFO] [stderr]    Compiling rand_xoshiro v0.8.0
[INFO] [stderr]    Compiling error-stack v0.7.0
[INFO] [stderr]    Compiling crossbeam-channel v0.5.15
[INFO] [stderr]    Compiling base64-serde v0.8.0
[INFO] [stderr]    Compiling base64 v0.22.1
[INFO] [stderr]    Compiling ask-cli v0.3.0
[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/ask-cli-0.3.0/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(read_buf)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling toml v1.1.2+spec-1.1.0
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `ask-cli` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "bfd404c4bfcef0411d93ba10043d1ed55a53cba1fa66639f2bf49b796d4c9a71", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bfd404c4bfcef0411d93ba10043d1ed55a53cba1fa66639f2bf49b796d4c9a71", kill_on_drop: false }`
[INFO] [stdout] bfd404c4bfcef0411d93ba10043d1ed55a53cba1fa66639f2bf49b796d4c9a71
