[INFO] fetching crate smart-read 0.9.0...
[INFO] testing smart-read-0.9.0 against beta-2026-04-21 for beta-1.96-2
[INFO] extracting crate smart-read 0.9.0 into /workspace/builds/worker-2-tc2/source
[INFO] started tweaking crates.io crate smart-read 0.9.0
[INFO] removed 0 missing examples
[INFO] finished tweaking crates.io crate smart-read 0.9.0
[INFO] tweaked toml for crates.io crate smart-read 0.9.0 written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate smart-read 0.9.0 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 smart-read 0.9.0 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-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 65f8909b2392116cbd11d7d026e9dbca6b7d7db01862ef6c8d0437ee9d462eb5
[INFO] running `Command { std: "docker" "start" "-a" "65f8909b2392116cbd11d7d026e9dbca6b7d7db01862ef6c8d0437ee9d462eb5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "65f8909b2392116cbd11d7d026e9dbca6b7d7db01862ef6c8d0437ee9d462eb5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "65f8909b2392116cbd11d7d026e9dbca6b7d7db01862ef6c8d0437ee9d462eb5", kill_on_drop: false }`
[INFO] [stdout] 65f8909b2392116cbd11d7d026e9dbca6b7d7db01862ef6c8d0437ee9d462eb5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 3f885f9c70c17dfe95f6e61274c75f28ef39eb14b4ca7a2937701090361ae571
[INFO] running `Command { std: "docker" "start" "-a" "3f885f9c70c17dfe95f6e61274c75f28ef39eb14b4ca7a2937701090361ae571", kill_on_drop: false }`
[INFO] [stderr]    Compiling smart-read v0.9.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]    --> src/lib.rs:142:1
[INFO] [stdout]     |
[INFO] [stdout] 142 | #![feature(let_chains)]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]     |
[INFO] [stdout]     = help: the feature `let_chains` has been stable since `1.88.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `let_chains` has been stable since 1.88.0 and no longer requires an attribute to enable
[INFO] [stdout]    --> src/lib.rs:142:12
[INFO] [stdout]     |
[INFO] [stdout] 142 | #![feature(let_chains)]
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `smart-read` (lib) due to 1 previous error; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "3f885f9c70c17dfe95f6e61274c75f28ef39eb14b4ca7a2937701090361ae571", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3f885f9c70c17dfe95f6e61274c75f28ef39eb14b4ca7a2937701090361ae571", kill_on_drop: false }`
[INFO] [stdout] 3f885f9c70c17dfe95f6e61274c75f28ef39eb14b4ca7a2937701090361ae571
