[INFO] cloning repository https://github.com/gwencasey96/rust-os-follow-along
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/gwencasey96/rust-os-follow-along" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgwencasey96%2Frust-os-follow-along", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgwencasey96%2Frust-os-follow-along'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d88838da46be1afcc8414fa643d9e978d5bfadaf
[INFO] testing gwencasey96/rust-os-follow-along against beta-2026-04-21 for beta-1.96-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgwencasey96%2Frust-os-follow-along" "/workspace/builds/worker-3-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc2/source'...
[INFO] [stderr] done.
[INFO] removed /workspace/builds/worker-3-tc2/source/.cargo/config.toml
[INFO] started tweaking git repo https://github.com/gwencasey96/rust-os-follow-along
[INFO] finished tweaking git repo https://github.com/gwencasey96/rust-os-follow-along
[INFO] tweaked toml for git repo https://github.com/gwencasey96/rust-os-follow-along written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/gwencasey96/rust-os-follow-along 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 git repo https://github.com/gwencasey96/rust-os-follow-along 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-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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] a23baccae32df8e364c28e7431e65ff80ad6571ce4cbabd517f564c993165bde
[INFO] running `Command { std: "docker" "start" "-a" "a23baccae32df8e364c28e7431e65ff80ad6571ce4cbabd517f564c993165bde", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a23baccae32df8e364c28e7431e65ff80ad6571ce4cbabd517f564c993165bde", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a23baccae32df8e364c28e7431e65ff80ad6571ce4cbabd517f564c993165bde", kill_on_drop: false }`
[INFO] [stdout] a23baccae32df8e364c28e7431e65ff80ad6571ce4cbabd517f564c993165bde
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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] d7059627dc2c0eb7ada165db943dceaa36de2b921a7a27e56dd2b275183bbaa2
[INFO] running `Command { std: "docker" "start" "-a" "d7059627dc2c0eb7ada165db943dceaa36de2b921a7a27e56dd2b275183bbaa2", kill_on_drop: false }`
[INFO] [stderr]    Compiling rustversion v1.0.22
[INFO] [stderr]    Compiling bitflags v2.11.0
[INFO] [stderr]    Compiling volatile v0.4.6
[INFO] [stderr]    Compiling bit_field v0.10.3
[INFO] [stderr]    Compiling bootloader v0.9.34
[INFO] [stderr]    Compiling spin v0.9.8
[INFO] [stderr]    Compiling bitflags v1.3.2
[INFO] [stderr]    Compiling spin v0.5.2
[INFO] [stderr]    Compiling pc-keyboard v0.7.0
[INFO] [stderr]    Compiling volatile v0.2.7
[INFO] [stderr]    Compiling lazy_static v1.5.0
[INFO] [stderr]    Compiling x86_64 v0.14.13
[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/x86_64-0.14.13/src/lib.rs:5:35
[INFO] [stdout]   |
[INFO] [stdout] 5 | #![cfg_attr(feature = "const_fn", feature(const_mut_refs))] // GDT add_entry()
[INFO] [stdout]   |                                   ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `const_mut_refs` has been stable since `1.83.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `x86_64` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "d7059627dc2c0eb7ada165db943dceaa36de2b921a7a27e56dd2b275183bbaa2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d7059627dc2c0eb7ada165db943dceaa36de2b921a7a27e56dd2b275183bbaa2", kill_on_drop: false }`
[INFO] [stdout] d7059627dc2c0eb7ada165db943dceaa36de2b921a7a27e56dd2b275183bbaa2