[INFO] fetching crate harbourmaster 0.3.0...
[INFO] documenting harbourmaster-0.3.0 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate harbourmaster 0.3.0 into /workspace/builds/worker-10/source
[INFO] validating manifest of crates.io crate harbourmaster 0.3.0 on toolchain beta-2020-08-29
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate harbourmaster 0.3.0
[INFO] finished tweaking crates.io crate harbourmaster 0.3.0
[INFO] tweaked toml for crates.io crate harbourmaster 0.3.0 written to /workspace/builds/worker-10/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "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-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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" "+beta-2020-08-29" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] dadcbcb990c1deac760f06b3be7280c1e8015a9f13cf0ba7a8fde373d35c4d51
[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" "dadcbcb990c1deac760f06b3be7280c1e8015a9f13cf0ba7a8fde373d35c4d51", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "dadcbcb990c1deac760f06b3be7280c1e8015a9f13cf0ba7a8fde373d35c4d51", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dadcbcb990c1deac760f06b3be7280c1e8015a9f13cf0ba7a8fde373d35c4d51", kill_on_drop: false }`
[INFO] [stdout] dadcbcb990c1deac760f06b3be7280c1e8015a9f13cf0ba7a8fde373d35c4d51
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 48c7750451aac4d05f7c3076a964a4666edfd7c6171e9a463a9455fa56088e71
[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" "48c7750451aac4d05f7c3076a964a4666edfd7c6171e9a463a9455fa56088e71", kill_on_drop: false }`
[INFO] [stderr]    Compiling hyper-openssl v0.7.1
[INFO] [stderr]     Checking xattr v0.2.2
[INFO] [stderr]     Checking filetime v0.2.12
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking tokio-openssl v0.3.0
[INFO] [stderr]     Checking hyperlocal v0.6.0
[INFO] [stderr]     Checking tar v0.4.30
[INFO] [stderr]     Checking shiplift v0.5.0
[INFO] [stderr]     Checking futures-executor-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking futures-preview v0.3.0-alpha.19
[INFO] [stderr]  Documenting harbourmaster v0.3.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(async_await)]
[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 `harbourmaster`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name harbourmaster 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-8dcce9a3f46f3246.rmeta --extern lazy_static=/opt/rustwide/target/debug/deps/liblazy_static-db88f49d9e5662e7.rmeta --extern log=/opt/rustwide/target/debug/deps/liblog-8b25aaf2e71705fc.rmeta --extern rand=/opt/rustwide/target/debug/deps/librand-98ed040c61a36189.rmeta --extern shiplift=/opt/rustwide/target/debug/deps/libshiplift-eb9cc21610754c3f.rmeta --extern tokio=/opt/rustwide/target/debug/deps/libtokio-5a02e79c0add5477.rmeta --cap-lints=warn --crate-version 0.3.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "48c7750451aac4d05f7c3076a964a4666edfd7c6171e9a463a9455fa56088e71", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "48c7750451aac4d05f7c3076a964a4666edfd7c6171e9a463a9455fa56088e71", kill_on_drop: false }`
[INFO] [stdout] 48c7750451aac4d05f7c3076a964a4666edfd7c6171e9a463a9455fa56088e71