[INFO] cloning repository https://github.com/ktact/mustard
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ktact/mustard" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fktact%2Fmustard", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fktact%2Fmustard'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 2b6f4db34020bdad00189cfce851fef6df46eafc
[INFO] testing ktact/mustard 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%2Fktact%2Fmustard" "/workspace/builds/worker-5-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc2/source'...
[INFO] [stderr] done.
[INFO] removed /workspace/builds/worker-5-tc2/source/.cargo/config.toml
[INFO] removed /workspace/builds/worker-5-tc2/source/rust-toolchain.toml
[INFO] started tweaking git repo https://github.com/ktact/mustard
[INFO] finished tweaking git repo https://github.com/ktact/mustard
[INFO] tweaked toml for git repo https://github.com/ktact/mustard written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/ktact/mustard 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/ktact/mustard 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-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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] 238ecc32c46dafaa85cf2856d0b46cb508a88e990772025a7f277d1a86f8e20d
[INFO] running `Command { std: "docker" "start" "-a" "238ecc32c46dafaa85cf2856d0b46cb508a88e990772025a7f277d1a86f8e20d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "238ecc32c46dafaa85cf2856d0b46cb508a88e990772025a7f277d1a86f8e20d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "238ecc32c46dafaa85cf2856d0b46cb508a88e990772025a7f277d1a86f8e20d", kill_on_drop: false }`
[INFO] [stdout] 238ecc32c46dafaa85cf2856d0b46cb508a88e990772025a7f277d1a86f8e20d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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] e45389a03324534c92413f678b33a08ea84727463c47daaafd6bdfdff5feaf91
[INFO] running `Command { std: "docker" "start" "-a" "e45389a03324534c92413f678b33a08ea84727463c47daaafd6bdfdff5feaf91", kill_on_drop: false }`
[INFO] [stderr]    Compiling mustard 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:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(offset_of)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_caller_location` has been stable since 1.79.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:5:12
[INFO] [stdout]   |
[INFO] [stdout] 5 | #![feature(const_caller_location)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_location_fields` has been stable since 1.79.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:6:12
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![feature(const_location_fields)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `offset_of` has been stable since 1.77.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(offset_of)]
[INFO] [stdout]   |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `option_get_or_insert_default` has been stable since 1.83.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:7:12
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![feature(option_get_or_insert_default)]
[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 `mustard` (lib) due to 1 previous error; 4 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "e45389a03324534c92413f678b33a08ea84727463c47daaafd6bdfdff5feaf91", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e45389a03324534c92413f678b33a08ea84727463c47daaafd6bdfdff5feaf91", kill_on_drop: false }`
[INFO] [stdout] e45389a03324534c92413f678b33a08ea84727463c47daaafd6bdfdff5feaf91
