[INFO] fetching crate generator_extensions 0.1.1...
[INFO] testing generator_extensions-0.1.1 against 1.59.0 for beta-1.60-1
[INFO] extracting crate generator_extensions 0.1.1 into /workspace/builds/worker-16/source
[INFO] validating manifest of crates.io crate generator_extensions 0.1.1 on toolchain 1.59.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate generator_extensions 0.1.1
[INFO] finished tweaking crates.io crate generator_extensions 0.1.1
[INFO] tweaked toml for crates.io crate generator_extensions 0.1.1 written to /workspace/builds/worker-16/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-16/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-16/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d257f362e9de149f7a78b51da180abf2da88536a11ef8f836246d55cd9db4f5d
[INFO] running `Command { std: "docker" "start" "-a" "d257f362e9de149f7a78b51da180abf2da88536a11ef8f836246d55cd9db4f5d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d257f362e9de149f7a78b51da180abf2da88536a11ef8f836246d55cd9db4f5d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d257f362e9de149f7a78b51da180abf2da88536a11ef8f836246d55cd9db4f5d", kill_on_drop: false }`
[INFO] [stdout] d257f362e9de149f7a78b51da180abf2da88536a11ef8f836246d55cd9db4f5d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-16/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-16/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] df86ad6c3ec5a77c8b8626f0c948b01ece9643733e04d2a771ac6c5c3b00364b
[INFO] running `Command { std: "docker" "start" "-a" "df86ad6c3ec5a77c8b8626f0c948b01ece9643733e04d2a771ac6c5c3b00364b", kill_on_drop: false }`
[INFO] [stderr]    Compiling generator_extensions v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:9:12
[INFO] [stdout]   |
[INFO] [stdout] 9 | #![feature(generator_trait)]
[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 `generator_extensions` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "df86ad6c3ec5a77c8b8626f0c948b01ece9643733e04d2a771ac6c5c3b00364b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "df86ad6c3ec5a77c8b8626f0c948b01ece9643733e04d2a771ac6c5c3b00364b", kill_on_drop: false }`
[INFO] [stdout] df86ad6c3ec5a77c8b8626f0c948b01ece9643733e04d2a771ac6c5c3b00364b