[INFO] fetching crate rundo_attrs 0.4.0...
[INFO] documenting rundo_attrs-0.4.0 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate rundo_attrs 0.4.0 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate rundo_attrs 0.4.0 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 rundo_attrs 0.4.0
[INFO] finished tweaking crates.io crate rundo_attrs 0.4.0
[INFO] tweaked toml for crates.io crate rundo_attrs 0.4.0 written to /workspace/builds/worker-14/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]  Downloading crates ...
[INFO] [stderr]   Downloaded rundo_types v0.4.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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] 017004fb98ef6d8901b7e4315e5e9464b23d6b0ea22f7d783885fb065f096fe3
[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" "017004fb98ef6d8901b7e4315e5e9464b23d6b0ea22f7d783885fb065f096fe3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "017004fb98ef6d8901b7e4315e5e9464b23d6b0ea22f7d783885fb065f096fe3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "017004fb98ef6d8901b7e4315e5e9464b23d6b0ea22f7d783885fb065f096fe3", kill_on_drop: false }`
[INFO] [stdout] 017004fb98ef6d8901b7e4315e5e9464b23d6b0ea22f7d783885fb065f096fe3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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] 3a5cc0541ff88808020e7ee42601b4e5c454c6c3d22e8d88cb6784b2c72f87a6
[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" "3a5cc0541ff88808020e7ee42601b4e5c454c6c3d22e8d88cb6784b2c72f87a6", kill_on_drop: false }`
[INFO] [stderr]     Checking proc-macro2 v0.2.3
[INFO] [stderr]     Checking rundo_types v0.4.0
[INFO] [stderr]     Checking quote v0.4.2
[INFO] [stderr]     Checking syn v0.12.15
[INFO] [stderr]  Documenting rundo_attrs v0.4.0 (/opt/rustwide/workdir)
[INFO] [stderr] error: Could not document `rundo_attrs`.
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(proc_macro)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] Caused by:
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type proc-macro --crate-name rundo_attrs 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 quote=/opt/rustwide/target/debug/deps/libquote-62cd06a97c88b5ca.rmeta --extern rundo_types=/opt/rustwide/target/debug/deps/librundo_types-51e9d32053c31c80.rmeta --extern syn=/opt/rustwide/target/debug/deps/libsyn-295ad9bf304085d6.rmeta --extern proc_macro --cap-lints=warn --crate-version 0.4.0` (exit code: 1)
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "3a5cc0541ff88808020e7ee42601b4e5c454c6c3d22e8d88cb6784b2c72f87a6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3a5cc0541ff88808020e7ee42601b4e5c454c6c3d22e8d88cb6784b2c72f87a6", kill_on_drop: false }`
[INFO] [stdout] 3a5cc0541ff88808020e7ee42601b4e5c454c6c3d22e8d88cb6784b2c72f87a6