[INFO] fetching crate gen-stream 0.2.4...
[INFO] documenting gen-stream-0.2.4 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate gen-stream 0.2.4 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate gen-stream 0.2.4 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 gen-stream 0.2.4
[INFO] finished tweaking crates.io crate gen-stream 0.2.4
[INFO] tweaked toml for crates.io crate gen-stream 0.2.4 written to /workspace/builds/worker-3/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] [stderr]     Blocking waiting for file lock on package cache
[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-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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] dafe277e6d9bc230f87b1db8676177e61cf4c841f7ec64517a132f63c1d99e4d
[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" "dafe277e6d9bc230f87b1db8676177e61cf4c841f7ec64517a132f63c1d99e4d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "dafe277e6d9bc230f87b1db8676177e61cf4c841f7ec64517a132f63c1d99e4d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dafe277e6d9bc230f87b1db8676177e61cf4c841f7ec64517a132f63c1d99e4d", kill_on_drop: false }`
[INFO] [stdout] dafe277e6d9bc230f87b1db8676177e61cf4c841f7ec64517a132f63c1d99e4d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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] 1a8f5d9cafb3aa48ab149839e676ee2e0a15fc9ea7c5552d35dab46ac536c7cc
[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" "1a8f5d9cafb3aa48ab149839e676ee2e0a15fc9ea7c5552d35dab46ac536c7cc", kill_on_drop: false }`
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.19
[INFO] [stderr]  Documenting gen-stream v0.2.4 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0432]: unresolved import `std::future::set_task_context`
[INFO] [stdout]   --> src/lib.rs:79:5
[INFO] [stdout]    |
[INFO] [stdout] 79 |     std::future::set_task_context,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no `set_task_context` in `future`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:67:1
[INFO] [stdout]    |
[INFO] [stdout] 67 | #![feature(generator_trait)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:68:1
[INFO] [stdout]    |
[INFO] [stdout] 68 | #![feature(gen_future)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:69:1
[INFO] [stdout]    |
[INFO] [stdout] 69 | #![feature(never_type)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 5 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[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] [stderr] error: Could not document `gen-stream`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name gen_stream 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_core=/opt/rustwide/target/debug/deps/libfutures_core-151fbb949682e309.rmeta --extern pin_utils=/opt/rustwide/target/debug/deps/libpin_utils-f9e49bc7e7f315e9.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "1a8f5d9cafb3aa48ab149839e676ee2e0a15fc9ea7c5552d35dab46ac536c7cc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1a8f5d9cafb3aa48ab149839e676ee2e0a15fc9ea7c5552d35dab46ac536c7cc", kill_on_drop: false }`
[INFO] [stdout] 1a8f5d9cafb3aa48ab149839e676ee2e0a15fc9ea7c5552d35dab46ac536c7cc