[INFO] cloning repository https://github.com/kstrafe/mutcy
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/kstrafe/mutcy" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkstrafe%2Fmutcy", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkstrafe%2Fmutcy'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 051f34f92f23e4704141c1a6610b0867f1b1063f
[INFO] testing kstrafe/mutcy 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%2Fkstrafe%2Fmutcy" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/kstrafe/mutcy
[INFO] finished tweaking git repo https://github.com/kstrafe/mutcy
[INFO] tweaked toml for git repo https://github.com/kstrafe/mutcy written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/kstrafe/mutcy 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/kstrafe/mutcy 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-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] 00472f423265d5a5f11b74035d5a9528b3e2eeb8b85191940bb6426c181a751f
[INFO] running `Command { std: "docker" "start" "-a" "00472f423265d5a5f11b74035d5a9528b3e2eeb8b85191940bb6426c181a751f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "00472f423265d5a5f11b74035d5a9528b3e2eeb8b85191940bb6426c181a751f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "00472f423265d5a5f11b74035d5a9528b3e2eeb8b85191940bb6426c181a751f", kill_on_drop: false }`
[INFO] [stdout] 00472f423265d5a5f11b74035d5a9528b3e2eeb8b85191940bb6426c181a751f
[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] 28b65387f263503d486bd7e980c961180ddb00a2ead268ac9287ac864954acaa
[INFO] running `Command { std: "docker" "start" "-a" "28b65387f263503d486bd7e980c961180ddb00a2ead268ac9287ac864954acaa", kill_on_drop: false }`
[INFO] [stderr]    Compiling mutcy v0.5.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]    --> src/lib.rs:130:1
[INFO] [stdout]     |
[INFO] [stdout] 130 | #![feature(arbitrary_self_types)]
[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 `mutcy` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "28b65387f263503d486bd7e980c961180ddb00a2ead268ac9287ac864954acaa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "28b65387f263503d486bd7e980c961180ddb00a2ead268ac9287ac864954acaa", kill_on_drop: false }`
[INFO] [stdout] 28b65387f263503d486bd7e980c961180ddb00a2ead268ac9287ac864954acaa
