[INFO] fetching crate korat 0.2.0...
[INFO] documenting korat-0.2.0 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate korat 0.2.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate korat 0.2.0 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 korat 0.2.0
[INFO] finished tweaking crates.io crate korat 0.2.0
[INFO] tweaked toml for crates.io crate korat 0.2.0 written to /workspace/builds/worker-4/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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] 21099774f59f4ce54a4d118a6d9ef47e22f84f8881fd4314b04a3aed0b50336f
[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" "21099774f59f4ce54a4d118a6d9ef47e22f84f8881fd4314b04a3aed0b50336f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "21099774f59f4ce54a4d118a6d9ef47e22f84f8881fd4314b04a3aed0b50336f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "21099774f59f4ce54a4d118a6d9ef47e22f84f8881fd4314b04a3aed0b50336f", kill_on_drop: false }`
[INFO] [stdout] 21099774f59f4ce54a4d118a6d9ef47e22f84f8881fd4314b04a3aed0b50336f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] 74e75b8135612ce10c85491e3ac9f4f6c1997c7ea1f880eaf087e4e1c5ec0513
[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" "74e75b8135612ce10c85491e3ac9f4f6c1997c7ea1f880eaf087e4e1c5ec0513", kill_on_drop: false }`
[INFO] [stderr]     Checking once_cell v1.4.1
[INFO] [stderr]     Checking shlex v0.1.1
[INFO] [stderr]     Checking zeroize v1.1.0
[INFO] [stderr]     Checking md5 v0.7.0
[INFO] [stderr]     Checking quick-error v2.0.0
[INFO] [stderr]    Compiling rusoto_core v0.45.0
[INFO] [stderr]     Checking crypto-mac v0.8.0
[INFO] [stderr]    Compiling async-trait v0.1.40
[INFO] [stderr]     Checking chrono v0.4.15
[INFO] [stderr]     Checking tokio v0.2.22
[INFO] [stderr]     Checking futures-task v0.3.5
[INFO] [stderr]     Checking hmac v0.8.1
[INFO] [stderr]     Checking futures-util v0.3.5
[INFO] [stderr]     Checking tokio-util v0.3.1
[INFO] [stderr]     Checking tokio-tls v0.3.1
[INFO] [stderr]     Checking h2 v0.2.6
[INFO] [stderr]     Checking futures-executor v0.3.5
[INFO] [stderr]     Checking futures v0.3.5
[INFO] [stderr]     Checking hyper v0.13.7
[INFO] [stderr]     Checking rusoto_credential v0.45.0
[INFO] [stderr]     Checking hyper-tls v0.4.3
[INFO] [stderr]     Checking rusoto_signature v0.45.0
[INFO] [stderr]     Checking rusoto_dynamodb v0.45.0
[INFO] [stderr]  Documenting korat v0.2.0 (/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(try_from, decl_macro)]
[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 `korat`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name korat 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 quick_error=/opt/rustwide/target/debug/deps/libquick_error-c3f7eac404e17977.rmeta --extern rusoto_dynamodb=/opt/rustwide/target/debug/deps/librusoto_dynamodb-c49f6aed476c2a41.rmeta --cap-lints=warn --crate-version 0.2.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "74e75b8135612ce10c85491e3ac9f4f6c1997c7ea1f880eaf087e4e1c5ec0513", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "74e75b8135612ce10c85491e3ac9f4f6c1997c7ea1f880eaf087e4e1c5ec0513", kill_on_drop: false }`
[INFO] [stdout] 74e75b8135612ce10c85491e3ac9f4f6c1997c7ea1f880eaf087e4e1c5ec0513