[INFO] fetching crate aktoro-runtime 0.1.0-alpha.4...
[INFO] documenting aktoro-runtime-0.1.0-alpha.4 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate aktoro-runtime 0.1.0-alpha.4 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate aktoro-runtime 0.1.0-alpha.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 aktoro-runtime 0.1.0-alpha.4
[INFO] finished tweaking crates.io crate aktoro-runtime 0.1.0-alpha.4
[INFO] tweaked toml for crates.io crate aktoro-runtime 0.1.0-alpha.4 written to /workspace/builds/worker-6/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-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] cd8870847e0e5d7ef7623755deb2062ee0be569a715e895e9deff020369667e6
[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" "cd8870847e0e5d7ef7623755deb2062ee0be569a715e895e9deff020369667e6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cd8870847e0e5d7ef7623755deb2062ee0be569a715e895e9deff020369667e6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cd8870847e0e5d7ef7623755deb2062ee0be569a715e895e9deff020369667e6", kill_on_drop: false }`
[INFO] [stdout] cd8870847e0e5d7ef7623755deb2062ee0be569a715e895e9deff020369667e6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] 4946e8168aec00812adc44a526c190012a5e73a531472ec86a43b08d1f4f9aa3
[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" "4946e8168aec00812adc44a526c190012a5e73a531472ec86a43b08d1f4f9aa3", kill_on_drop: false }`
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling proc-macro2 v1.0.19
[INFO] [stderr]     Checking futures-io-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling syn v1.0.39
[INFO] [stderr]     Checking crossbeam-utils v0.6.6
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking rand_xoshiro v0.2.0
[INFO] [stderr]     Checking crossbeam-queue v0.1.2
[INFO] [stderr]     Checking futures-channel-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking aktoro-raw v0.1.0-alpha.4
[INFO] [stderr]     Checking aktoro-channel v0.1.0-alpha.8
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]     Checking futures-executor-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking futures-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking runtime-raw v0.3.0-alpha.5
[INFO] [stderr]    Compiling pin-project-internal v0.4.23
[INFO] [stderr]    Compiling runtime-attributes v0.3.0-alpha.6
[INFO] [stderr]     Checking pin-project v0.4.23
[INFO] [stderr]     Checking runtime v0.3.0-alpha.8
[INFO] [stderr]  Documenting aktoro-runtime v0.1.0-alpha.4 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![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 `aktoro-runtime`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name aktoro_runtime 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 aktoro_channel=/opt/rustwide/target/debug/deps/libaktoro_channel-dee78adefe7842b2.rmeta --extern aktoro_raw=/opt/rustwide/target/debug/deps/libaktoro_raw-cace0098f0e0e6dc.rmeta --extern fnv=/opt/rustwide/target/debug/deps/libfnv-6f83b5744b59dc2d.rmeta --extern futures_core=/opt/rustwide/target/debug/deps/libfutures_core-151fbb949682e309.rmeta --extern futures_io=/opt/rustwide/target/debug/deps/libfutures_io-720833281ff54b5a.rmeta --extern rand=/opt/rustwide/target/debug/deps/librand-9b356e0eb33fe2d1.rmeta --extern rand_xoshiro=/opt/rustwide/target/debug/deps/librand_xoshiro-6b105d38a9b18cee.rmeta --extern runtime=/opt/rustwide/target/debug/deps/libruntime-42c7ebb200fbc54c.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "4946e8168aec00812adc44a526c190012a5e73a531472ec86a43b08d1f4f9aa3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4946e8168aec00812adc44a526c190012a5e73a531472ec86a43b08d1f4f9aa3", kill_on_drop: false }`
[INFO] [stdout] 4946e8168aec00812adc44a526c190012a5e73a531472ec86a43b08d1f4f9aa3