[INFO] fetching crate percy-webapis 0.0.2...
[INFO] testing percy-webapis-0.0.2 against 1.49.0 for beta-1.50-1
[INFO] extracting crate percy-webapis 0.0.2 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate percy-webapis 0.0.2 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate percy-webapis 0.0.2
[INFO] finished tweaking crates.io crate percy-webapis 0.0.2
[INFO] tweaked toml for crates.io crate percy-webapis 0.0.2 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 29df3d358c7183d3a7fe40547c2b96edd2262abd2e9c97392633f3c038b150d7
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "29df3d358c7183d3a7fe40547c2b96edd2262abd2e9c97392633f3c038b150d7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "29df3d358c7183d3a7fe40547c2b96edd2262abd2e9c97392633f3c038b150d7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "29df3d358c7183d3a7fe40547c2b96edd2262abd2e9c97392633f3c038b150d7", kill_on_drop: false }`
[INFO] [stdout] 29df3d358c7183d3a7fe40547c2b96edd2262abd2e9c97392633f3c038b150d7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0626f932d64ed9e846c61c947044cbc7d43a817343ca68f7b3a0b7f5f375994c
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "0626f932d64ed9e846c61c947044cbc7d43a817343ca68f7b3a0b7f5f375994c", kill_on_drop: false }`
[INFO] [stderr]    Compiling wasm-bindgen-shared v0.2.69
[INFO] [stderr]    Compiling bumpalo v3.4.0
[INFO] [stderr]    Compiling wasm-bindgen v0.2.69
[INFO] [stderr]    Compiling wasm-bindgen-backend v0.2.69
[INFO] [stderr]    Compiling wasm-bindgen-macro-support v0.2.69
[INFO] [stderr]    Compiling wasm-bindgen-macro v0.2.69
[INFO] [stderr]    Compiling percy-webapis v0.0.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(use_extern_macros)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/lib.rs:57:73
[INFO] [stdout]    |
[INFO] [stdout] 57 |     pub fn add_event_listener(this: &Element, event: &str, cb: &Closure<Fn()>);
[INFO] [stdout]    |                                                                         ^^^^ help: use `dyn`: `dyn Fn()`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/lib.rs:57:73
[INFO] [stdout]    |
[INFO] [stdout] 57 |     pub fn add_event_listener(this: &Element, event: &str, cb: &Closure<Fn()>);
[INFO] [stdout]    |                                                                         ^^^^ help: use `dyn`: `dyn Fn()`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `percy-webapis`
[INFO] [stdout] error: aborting due to previous error; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "0626f932d64ed9e846c61c947044cbc7d43a817343ca68f7b3a0b7f5f375994c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0626f932d64ed9e846c61c947044cbc7d43a817343ca68f7b3a0b7f5f375994c", kill_on_drop: false }`
[INFO] [stdout] 0626f932d64ed9e846c61c947044cbc7d43a817343ca68f7b3a0b7f5f375994c