[INFO] fetching crate tree-automata 0.1.0...
[INFO] documenting tree-automata-0.1.0 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate tree-automata 0.1.0 into /workspace/builds/worker-10/source
[INFO] validating manifest of crates.io crate tree-automata 0.1.0 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 tree-automata 0.1.0
[INFO] finished tweaking crates.io crate tree-automata 0.1.0
[INFO] tweaked toml for crates.io crate tree-automata 0.1.0 written to /workspace/builds/worker-10/source/Cargo.toml
[INFO] crate crates.io crate tree-automata 0.1.0 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]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded terms v0.1.1
[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] d91fde52485417816fc1ba6167e9e0e952d317dc720b04ffca337675a210255c
[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" "d91fde52485417816fc1ba6167e9e0e952d317dc720b04ffca337675a210255c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d91fde52485417816fc1ba6167e9e0e952d317dc720b04ffca337675a210255c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d91fde52485417816fc1ba6167e9e0e952d317dc720b04ffca337675a210255c", kill_on_drop: false }`
[INFO] [stdout] d91fde52485417816fc1ba6167e9e0e952d317dc720b04ffca337675a210255c
[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] b6bd300c2b3b5113d091a45874251201517d8e213ba61b4d7f9608600ca2cafa
[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" "b6bd300c2b3b5113d091a45874251201517d8e213ba61b4d7f9608600ca2cafa", kill_on_drop: false }`
[INFO] [stderr]    Compiling getrandom v0.1.11
[INFO] [stderr]     Checking crossbeam-utils v0.6.6
[INFO] [stderr]     Checking crossbeam-channel v0.3.9
[INFO] [stderr]     Checking rand_core v0.5.0
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking rand v0.7.0
[INFO] [stderr]     Checking terms v0.1.1
[INFO] [stderr]  Documenting tree-automata v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(trait_alias)]
[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 `tree-automata`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name tree_automata 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 crossbeam_channel=/opt/rustwide/target/debug/deps/libcrossbeam_channel-064caa7455802b6f.rmeta --extern terms=/opt/rustwide/target/debug/deps/libterms-477010d4455a9770.rmeta --cap-lints=warn --crate-version 0.1.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "b6bd300c2b3b5113d091a45874251201517d8e213ba61b4d7f9608600ca2cafa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b6bd300c2b3b5113d091a45874251201517d8e213ba61b4d7f9608600ca2cafa", kill_on_drop: false }`
[INFO] [stdout] b6bd300c2b3b5113d091a45874251201517d8e213ba61b4d7f9608600ca2cafa