[INFO] fetching crate basehangul 0.1.10...
[INFO] documenting basehangul-0.1.10 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate basehangul 0.1.10 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate basehangul 0.1.10 on toolchain 1.46.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate basehangul 0.1.10
[INFO] finished tweaking crates.io crate basehangul 0.1.10
[INFO] tweaked toml for crates.io crate basehangul 0.1.10 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] dd1e997566c0d09c07a2e4e51dbb900ea67c12691da017162a0d0b72ab8fc2b0
[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" "dd1e997566c0d09c07a2e4e51dbb900ea67c12691da017162a0d0b72ab8fc2b0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "dd1e997566c0d09c07a2e4e51dbb900ea67c12691da017162a0d0b72ab8fc2b0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dd1e997566c0d09c07a2e4e51dbb900ea67c12691da017162a0d0b72ab8fc2b0", kill_on_drop: false }`
[INFO] [stdout] dd1e997566c0d09c07a2e4e51dbb900ea67c12691da017162a0d0b72ab8fc2b0
[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" "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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e330006c12f933ee6993c25b1b66c2f9f13d605ba8debfa469552e0771d979ac
[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" "e330006c12f933ee6993c25b1b66c2f9f13d605ba8debfa469552e0771d979ac", kill_on_drop: false }`
[INFO] [stderr]  Documenting basehangul v0.1.10 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0432]: unresolved import `std::borrow::IntoCow`
[INFO] [stdout]   --> src/lib.rs:14:24
[INFO] [stdout]    |
[INFO] [stdout] 14 | use std::borrow::{Cow, IntoCow};
[INFO] [stdout]    |                        ^^^^^^^ no `IntoCow` in `borrow`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `basehangul`.
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | #![feature(into_cow)] // lib stability features as per RFC #507
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] Caused by:
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name basehangul src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern encoding_index_korean=/opt/rustwide/target/debug/deps/libencoding_index_korean-216e732b9d2e0cb5.rmeta --cap-lints=warn` (exit code: 1)
[INFO] [stdout] Some errors have detailed explanations: E0432, E0554.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "e330006c12f933ee6993c25b1b66c2f9f13d605ba8debfa469552e0771d979ac", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e330006c12f933ee6993c25b1b66c2f9f13d605ba8debfa469552e0771d979ac", kill_on_drop: false }`
[INFO] [stdout] e330006c12f933ee6993c25b1b66c2f9f13d605ba8debfa469552e0771d979ac