[INFO] fetching crate vertigo-browserdriver 0.1.0-alpha.2...
[INFO] testing vertigo-browserdriver-0.1.0-alpha.2 against 1.55.0 for beta-1.56-1
[INFO] extracting crate vertigo-browserdriver 0.1.0-alpha.2 into /workspace/builds/worker-15/source
[INFO] validating manifest of crates.io crate vertigo-browserdriver 0.1.0-alpha.2 on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate vertigo-browserdriver 0.1.0-alpha.2
[INFO] finished tweaking crates.io crate vertigo-browserdriver 0.1.0-alpha.2
[INFO] tweaked toml for crates.io crate vertigo-browserdriver 0.1.0-alpha.2 written to /workspace/builds/worker-15/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 281e90d7e4f9cc8b93ecc84bc630b94d7d1e37423d95c31b3493ce3064d3d23f
[INFO] running `Command { std: "docker" "start" "-a" "281e90d7e4f9cc8b93ecc84bc630b94d7d1e37423d95c31b3493ce3064d3d23f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "281e90d7e4f9cc8b93ecc84bc630b94d7d1e37423d95c31b3493ce3064d3d23f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "281e90d7e4f9cc8b93ecc84bc630b94d7d1e37423d95c31b3493ce3064d3d23f", kill_on_drop: false }`
[INFO] [stdout] 281e90d7e4f9cc8b93ecc84bc630b94d7d1e37423d95c31b3493ce3064d3d23f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 18cdc201573dd5b6c67e86e52d031eb5e061f0a33a338d3626ebcef40e3a3fc4
[INFO] running `Command { std: "docker" "start" "-a" "18cdc201573dd5b6c67e86e52d031eb5e061f0a33a338d3626ebcef40e3a3fc4", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling wasm-bindgen-shared v0.2.77
[INFO] [stderr]    Compiling bumpalo v3.7.0
[INFO] [stderr]    Compiling wasm-bindgen v0.2.77
[INFO] [stderr]    Compiling serde_json v1.0.67
[INFO] [stderr]    Compiling vertigo v0.1.0-alpha.2
[INFO] [stderr]    Compiling wasm-bindgen-backend v0.2.77
[INFO] [stderr]    Compiling wasm-bindgen-macro-support v0.2.77
[INFO] [stderr]    Compiling wasm-bindgen-macro v0.2.77
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/wasm-bindgen-0.2.77/src/lib.rs:11:34
[INFO] [stdout]    |
[INFO] [stdout] 11 | #![cfg_attr(feature = "nightly", feature(unsize))]
[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 `wasm-bindgen` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "18cdc201573dd5b6c67e86e52d031eb5e061f0a33a338d3626ebcef40e3a3fc4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "18cdc201573dd5b6c67e86e52d031eb5e061f0a33a338d3626ebcef40e3a3fc4", kill_on_drop: false }`
[INFO] [stdout] 18cdc201573dd5b6c67e86e52d031eb5e061f0a33a338d3626ebcef40e3a3fc4