[INFO] cloning repository https://github.com/tomasol/chat-async
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tomasol/chat-async" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftomasol%2Fchat-async", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftomasol%2Fchat-async'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3f9964e62e8fd5b0981732e7832e0523269e4b60
[INFO] documenting tomasol/chat-async against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftomasol%2Fchat-async" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tomasol/chat-async 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 git repo https://github.com/tomasol/chat-async
[INFO] finished tweaking git repo https://github.com/tomasol/chat-async
[INFO] tweaked toml for git repo https://github.com/tomasol/chat-async written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/tomasol/chat-async already has a lockfile, it will not be regenerated
[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]  Downloading crates ...
[INFO] [stderr]   Downloaded streamunordered v0.5.0
[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" "+beta-2020-08-29" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1288ef92b0b1d26b93e648cf0b1c3712b2e54e0c075f3caca92aa0ace37a8c02
[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" "1288ef92b0b1d26b93e648cf0b1c3712b2e54e0c075f3caca92aa0ace37a8c02", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1288ef92b0b1d26b93e648cf0b1c3712b2e54e0c075f3caca92aa0ace37a8c02", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1288ef92b0b1d26b93e648cf0b1c3712b2e54e0c075f3caca92aa0ace37a8c02", kill_on_drop: false }`
[INFO] [stdout] 1288ef92b0b1d26b93e648cf0b1c3712b2e54e0c075f3caca92aa0ace37a8c02
[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" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c61e06818b7bd6ac2fe7d5a50bbdd3a4b6b31d7ca3e11a3f3fdf3b13c596f885
[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" "c61e06818b7bd6ac2fe7d5a50bbdd3a4b6b31d7ca3e11a3f3fdf3b13c596f885", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.11
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking futures-core v0.3.1
[INFO] [stderr]     Checking futures-io v0.3.1
[INFO] [stderr]     Checking futures-sink v0.3.1
[INFO] [stderr]     Checking pin-utils v0.1.0-alpha.4
[INFO] [stderr]     Checking futures-task v0.3.1
[INFO] [stderr]     Checking once_cell v1.2.0
[INFO] [stderr]     Checking pin-project-lite v0.1.1
[INFO] [stderr]     Checking futures-timer v2.0.2
[INFO] [stderr]    Compiling crossbeam-utils v0.7.0
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.0
[INFO] [stderr]     Checking crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling memoffset v0.5.3
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking atty v0.2.13
[INFO] [stderr]     Checking num_cpus v1.11.1
[INFO] [stderr]     Checking futures-channel v0.3.1
[INFO] [stderr]     Checking async-task v1.0.0
[INFO] [stderr]     Checking crossbeam-channel v0.4.0
[INFO] [stderr]     Checking mio v0.6.21
[INFO] [stderr]     Checking kv-log-macro v1.0.4
[INFO] [stderr]     Checking env_logger v0.7.1
[INFO] [stderr]     Checking crossbeam-deque v0.7.2
[INFO] [stderr]     Checking mio-uds v0.6.7
[INFO] [stderr]    Compiling proc-macro-hack v0.5.11
[INFO] [stderr]    Compiling async-attributes v1.1.1
[INFO] [stderr]     Checking async-std v1.4.0
[INFO] [stderr]    Compiling futures-macro v0.3.1
[INFO] [stderr]     Checking futures-util v0.3.1
[INFO] [stderr]     Checking futures-executor v0.3.1
[INFO] [stderr]     Checking streamunordered v0.5.0
[INFO] [stderr]     Checking futures v0.3.1
[INFO] [stderr]  Documenting chat-async v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(async_closure)]
[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 `chat-async`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type bin --crate-name chat_async src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern async_std=/opt/rustwide/target/debug/deps/libasync_std-14f884954c16b323.rmeta --extern env_logger=/opt/rustwide/target/debug/deps/libenv_logger-657335ee8389b3c2.rmeta --extern futures=/opt/rustwide/target/debug/deps/libfutures-b47a39061d889e3a.rmeta --extern log=/opt/rustwide/target/debug/deps/liblog-6bdba6c1562fbb28.rmeta --extern streamunordered=/opt/rustwide/target/debug/deps/libstreamunordered-91d7ecf482d8d3c7.rmeta --cap-lints=warn --crate-version 0.1.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "c61e06818b7bd6ac2fe7d5a50bbdd3a4b6b31d7ca3e11a3f3fdf3b13c596f885", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c61e06818b7bd6ac2fe7d5a50bbdd3a4b6b31d7ca3e11a3f3fdf3b13c596f885", kill_on_drop: false }`
[INFO] [stdout] c61e06818b7bd6ac2fe7d5a50bbdd3a4b6b31d7ca3e11a3f3fdf3b13c596f885