[INFO] fetching crate polymer-core 0.1.0...
[INFO] documenting polymer-core-0.1.0 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate polymer-core 0.1.0 into /workspace/builds/worker-35/source
[INFO] validating manifest of crates.io crate polymer-core 0.1.0 on toolchain 1.61.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate polymer-core 0.1.0
[INFO] finished tweaking crates.io crate polymer-core 0.1.0
[INFO] tweaked toml for crates.io crate polymer-core 0.1.0 written to /workspace/builds/worker-35/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-35/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-35/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:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 78d2313fc5aad4cf20f3bfdcacece9f1704c63a490c7fc5c36f8f301136032ca
[INFO] running `Command { std: "docker" "start" "-a" "78d2313fc5aad4cf20f3bfdcacece9f1704c63a490c7fc5c36f8f301136032ca", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "78d2313fc5aad4cf20f3bfdcacece9f1704c63a490c7fc5c36f8f301136032ca", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "78d2313fc5aad4cf20f3bfdcacece9f1704c63a490c7fc5c36f8f301136032ca", kill_on_drop: false }`
[INFO] [stdout] 78d2313fc5aad4cf20f3bfdcacece9f1704c63a490c7fc5c36f8f301136032ca
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-35/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-35/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" "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:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a318e38e9069638513528adb39feeefb5ac2c17895f1aaa5fcaf5972331015d4
[INFO] running `Command { std: "docker" "start" "-a" "a318e38e9069638513528adb39feeefb5ac2c17895f1aaa5fcaf5972331015d4", kill_on_drop: false }`
[INFO] [stderr]    Compiling futures-core v0.3.21
[INFO] [stderr]  Documenting polymer-core v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error: could not document `polymer-core`
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:2:34
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(arbitrary_self_types, const_fn, never_type)]
[INFO] [stdout]   |                                  ^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: split into finer-grained feature gates
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(arbitrary_self_types, const_fn, never_type)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] Caused by:
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name embrio_core src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=7dd975f3b50f3eab -L dependency=/opt/rustwide/target/debug/deps --extern futures_core=/opt/rustwide/target/debug/deps/libfutures_core-901439d31494c880.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0557.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "a318e38e9069638513528adb39feeefb5ac2c17895f1aaa5fcaf5972331015d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a318e38e9069638513528adb39feeefb5ac2c17895f1aaa5fcaf5972331015d4", kill_on_drop: false }`
[INFO] [stdout] a318e38e9069638513528adb39feeefb5ac2c17895f1aaa5fcaf5972331015d4