[INFO] fetching crate futures-bufio 0.2.0...
[INFO] documenting futures-bufio-0.2.0 against 1.47.0 for beta-1.48-rustdoc-1
[INFO] extracting crate futures-bufio 0.2.0 into /workspace/builds/worker-11/source
[INFO] validating manifest of crates.io crate futures-bufio 0.2.0 on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate futures-bufio 0.2.0
[INFO] finished tweaking crates.io crate futures-bufio 0.2.0
[INFO] tweaked toml for crates.io crate futures-bufio 0.2.0 written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "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" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] bfd36c8c628116b42aa17d3da8e616ff972d54e1c176c272778db80866e78739
[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" "bfd36c8c628116b42aa17d3da8e616ff972d54e1c176c272778db80866e78739", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "bfd36c8c628116b42aa17d3da8e616ff972d54e1c176c272778db80866e78739", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bfd36c8c628116b42aa17d3da8e616ff972d54e1c176c272778db80866e78739", kill_on_drop: false }`
[INFO] [stdout] bfd36c8c628116b42aa17d3da8e616ff972d54e1c176c272778db80866e78739
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "+1.47.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6509c6cf5bb7d3aba6b030610c0be06469f5a43af3d8cf88cd5fa1ee47400230
[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" "6509c6cf5bb7d3aba6b030610c0be06469f5a43af3d8cf88cd5fa1ee47400230", kill_on_drop: false }`
[INFO] [stderr]  Documenting futures-bufio v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:10:1
[INFO] [stdout]    |
[INFO] [stdout] 10 | #![feature(conservative_impl_trait)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `futures-bufio`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name futures_bufio 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 futures=/opt/rustwide/target/debug/deps/libfutures-2f80a151d70e23d0.rmeta --extern futures_cpupool=/opt/rustwide/target/debug/deps/libfutures_cpupool-2eff4bb4e2391250.rmeta --cap-lints=warn --crate-version 0.2.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "6509c6cf5bb7d3aba6b030610c0be06469f5a43af3d8cf88cd5fa1ee47400230", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6509c6cf5bb7d3aba6b030610c0be06469f5a43af3d8cf88cd5fa1ee47400230", kill_on_drop: false }`
[INFO] [stdout] 6509c6cf5bb7d3aba6b030610c0be06469f5a43af3d8cf88cd5fa1ee47400230
