[INFO] fetching crate kakao-rs 0.2.4...
[INFO] documenting kakao-rs-0.2.4 against beta-2021-08-01 for beta-1.55-rustdoc-1
[INFO] extracting crate kakao-rs 0.2.4 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate kakao-rs 0.2.4 on toolchain beta-2021-08-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate kakao-rs 0.2.4
[INFO] removed 0 missing examples
[INFO] finished tweaking crates.io crate kakao-rs 0.2.4
[INFO] tweaked toml for crates.io crate kakao-rs 0.2.4 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate crates.io crate kakao-rs 0.2.4 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5f2d5b3225ed776ba5b3687f5f8b570aff6fca8e87dbc22bf8e7813d49a74662
[INFO] running `Command { std: "docker" "start" "-a" "5f2d5b3225ed776ba5b3687f5f8b570aff6fca8e87dbc22bf8e7813d49a74662", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5f2d5b3225ed776ba5b3687f5f8b570aff6fca8e87dbc22bf8e7813d49a74662", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5f2d5b3225ed776ba5b3687f5f8b570aff6fca8e87dbc22bf8e7813d49a74662", kill_on_drop: false }`
[INFO] [stdout] 5f2d5b3225ed776ba5b3687f5f8b570aff6fca8e87dbc22bf8e7813d49a74662
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 085a805e376cc8cefd450dca2555fda23a09c9c86ca74693875ea0f5561731e4
[INFO] running `Command { std: "docker" "start" "-a" "085a805e376cc8cefd450dca2555fda23a09c9c86ca74693875ea0f5561731e4", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde_json v1.0.65
[INFO] [stderr]    Compiling serde_derive v1.0.126
[INFO] [stderr]     Checking serde v1.0.126
[INFO] [stderr]  Documenting kakao-rs v0.2.4 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:41:1
[INFO] [stdout]    |
[INFO] [stdout] 41 | #![feature(proc_macro_hygiene, 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 `kakao-rs`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name kakao_rs 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 serde=/opt/rustwide/target/debug/deps/libserde-400d0f5cb8a8ad20.rmeta --extern serde_derive=/opt/rustwide/target/debug/deps/libserde_derive-6bb411b24419dad3.so --extern serde_json=/opt/rustwide/target/debug/deps/libserde_json-ce2b719af889d49a.rmeta --cap-lints=warn --crate-version 0.2.4` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "085a805e376cc8cefd450dca2555fda23a09c9c86ca74693875ea0f5561731e4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "085a805e376cc8cefd450dca2555fda23a09c9c86ca74693875ea0f5561731e4", kill_on_drop: false }`
[INFO] [stdout] 085a805e376cc8cefd450dca2555fda23a09c9c86ca74693875ea0f5561731e4
