[INFO] fetching crate utf8-bufread 1.0.0...
[INFO] testing utf8-bufread-1.0.0 against beta-2021-08-01 for beta-1.55-1
[INFO] extracting crate utf8-bufread 1.0.0 into /workspace/builds/worker-58/source
[INFO] validating manifest of crates.io crate utf8-bufread 1.0.0 on toolchain beta-2021-08-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate utf8-bufread 1.0.0
[INFO] finished tweaking crates.io crate utf8-bufread 1.0.0
[INFO] tweaked toml for crates.io crate utf8-bufread 1.0.0 written to /workspace/builds/worker-58/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-58/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-58/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 38b595f38ccde8250bbf79b34dd9aa7282b6d2c3e6310f6cbec0061d6c7febce
[INFO] running `Command { std: "docker" "start" "-a" "38b595f38ccde8250bbf79b34dd9aa7282b6d2c3e6310f6cbec0061d6c7febce", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "38b595f38ccde8250bbf79b34dd9aa7282b6d2c3e6310f6cbec0061d6c7febce", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "38b595f38ccde8250bbf79b34dd9aa7282b6d2c3e6310f6cbec0061d6c7febce", kill_on_drop: false }`
[INFO] [stdout] 38b595f38ccde8250bbf79b34dd9aa7282b6d2c3e6310f6cbec0061d6c7febce
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-58/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-58/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" "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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 06922752145f07cdf3c8978ba51c8f98fd6d0ab4b1bc116b99ead98b1727bf8a
[INFO] running `Command { std: "docker" "start" "-a" "06922752145f07cdf3c8978ba51c8f98fd6d0ab4b1bc116b99ead98b1727bf8a", kill_on_drop: false }`
[INFO] [stderr]    Compiling utf8-bufread v1.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(option_result_unwrap_unchecked)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `utf8-bufread` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "06922752145f07cdf3c8978ba51c8f98fd6d0ab4b1bc116b99ead98b1727bf8a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "06922752145f07cdf3c8978ba51c8f98fd6d0ab4b1bc116b99ead98b1727bf8a", kill_on_drop: false }`
[INFO] [stdout] 06922752145f07cdf3c8978ba51c8f98fd6d0ab4b1bc116b99ead98b1727bf8a
