[INFO] fetching crate tiered-result 0.1.0...
[INFO] testing tiered-result-0.1.0 against beta-2026-04-21 for beta-1.96-2
[INFO] extracting crate tiered-result 0.1.0 into /workspace/builds/worker-6-tc2/source
[INFO] started tweaking crates.io crate tiered-result 0.1.0
[INFO] finished tweaking crates.io crate tiered-result 0.1.0
[INFO] tweaked toml for crates.io crate tiered-result 0.1.0 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate tiered-result 0.1.0 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] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 1 package to latest compatible version
[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] [stderr] warning: `default_features` is deprecated in favor of `default-features` and will not work in the 2024 edition
[INFO] [stderr] (in the `nullable-result` dependency)
[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] 9de0b7afabefe5ba51f63f5efdf1ba780bc6f9a485031d9db4ca46c5f3bfa386
[INFO] running `Command { std: "docker" "start" "-a" "9de0b7afabefe5ba51f63f5efdf1ba780bc6f9a485031d9db4ca46c5f3bfa386", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9de0b7afabefe5ba51f63f5efdf1ba780bc6f9a485031d9db4ca46c5f3bfa386", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9de0b7afabefe5ba51f63f5efdf1ba780bc6f9a485031d9db4ca46c5f3bfa386", kill_on_drop: false }`
[INFO] [stdout] 9de0b7afabefe5ba51f63f5efdf1ba780bc6f9a485031d9db4ca46c5f3bfa386
[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] 120a943805156c53277415d279eff00502af56daac2f2fe05631880aa028d9d5
[INFO] running `Command { std: "docker" "start" "-a" "120a943805156c53277415d279eff00502af56daac2f2fe05631880aa028d9d5", kill_on_drop: false }`
[INFO] [stderr] warning: `default_features` is deprecated in favor of `default-features` and will not work in the 2024 edition
[INFO] [stderr] (in the `nullable-result` dependency)
[INFO] [stderr]    Compiling nullable-result v0.7.0
[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/nullable-result-0.7.0/src/lib.rs:11:36
[INFO] [stdout]    |
[INFO] [stdout] 11 | #![cfg_attr(feature = "try_trait", feature(try_trait_v2))]
[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 `nullable-result` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "120a943805156c53277415d279eff00502af56daac2f2fe05631880aa028d9d5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "120a943805156c53277415d279eff00502af56daac2f2fe05631880aa028d9d5", kill_on_drop: false }`
[INFO] [stdout] 120a943805156c53277415d279eff00502af56daac2f2fe05631880aa028d9d5
