[INFO] fetching crate revent 0.29.0...
[INFO] documenting revent-0.29.0 against beta-2020-10-09 for beta-1.48-rustdoc-1
[INFO] extracting crate revent 0.29.0 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate revent 0.29.0 on toolchain beta-2020-10-09
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-10-09" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate revent 0.29.0
[INFO] finished tweaking crates.io crate revent 0.29.0
[INFO] tweaked toml for crates.io crate revent 0.29.0 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate crates.io crate revent 0.29.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-10-09" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded isize-vec v0.1.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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-2020-10-09" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b63094dd66ac78a9f0950b7ad8c717da4a72df6637337ca8187ac3d3d21fe6d7
[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" "b63094dd66ac78a9f0950b7ad8c717da4a72df6637337ca8187ac3d3d21fe6d7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b63094dd66ac78a9f0950b7ad8c717da4a72df6637337ca8187ac3d3d21fe6d7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b63094dd66ac78a9f0950b7ad8c717da4a72df6637337ca8187ac3d3d21fe6d7", kill_on_drop: false }`
[INFO] [stdout] b63094dd66ac78a9f0950b7ad8c717da4a72df6637337ca8187ac3d3d21fe6d7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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-2020-10-09" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ce2329eb5fa8e876e31a17dfb6e5b1f2f1be5e81af4b08faaee9747b01d45ac7
[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" "ce2329eb5fa8e876e31a17dfb6e5b1f2f1be5e81af4b08faaee9747b01d45ac7", kill_on_drop: false }`
[INFO] [stderr]     Checking isize-vec v0.1.1
[INFO] [stderr]  Documenting revent v0.29.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:63:1
[INFO] [stdout]    |
[INFO] [stdout] 63 | #![feature(coerce_unsized, drain_filter, unsize)]
[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 `revent`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name revent 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 isize_vec=/opt/rustwide/target/debug/deps/libisize_vec-8ffc86ec6572fcb7.rmeta --cap-lints=warn --crate-version 0.29.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "ce2329eb5fa8e876e31a17dfb6e5b1f2f1be5e81af4b08faaee9747b01d45ac7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ce2329eb5fa8e876e31a17dfb6e5b1f2f1be5e81af4b08faaee9747b01d45ac7", kill_on_drop: false }`
[INFO] [stdout] ce2329eb5fa8e876e31a17dfb6e5b1f2f1be5e81af4b08faaee9747b01d45ac7
