[INFO] fetching crate arc-rs 0.5.1...
[INFO] documenting arc-rs-0.5.1 against 1.54.0 for beta-1.55-rustdoc-1
[INFO] extracting crate arc-rs 0.5.1 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate arc-rs 0.5.1 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate arc-rs 0.5.1
[INFO] finished tweaking crates.io crate arc-rs 0.5.1
[INFO] tweaked toml for crates.io crate arc-rs 0.5.1 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--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 arc-pest v0.4.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6a1f350f1fd48dea283220762665a4807a75f58e505b128b384488df05353009
[INFO] running `Command { std: "docker" "start" "-a" "6a1f350f1fd48dea283220762665a4807a75f58e505b128b384488df05353009", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6a1f350f1fd48dea283220762665a4807a75f58e505b128b384488df05353009", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6a1f350f1fd48dea283220762665a4807a75f58e505b128b384488df05353009", kill_on_drop: false }`
[INFO] [stdout] 6a1f350f1fd48dea283220762665a4807a75f58e505b128b384488df05353009
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "+1.54.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8503927e9b9b71d97f6296bb36276874b650d131b7db6c04f316b07009e2d100
[INFO] running `Command { std: "docker" "start" "-a" "8503927e9b9b71d97f6296bb36276874b650d131b7db6c04f316b07009e2d100", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde_json v1.0.66
[INFO] [stderr]    Compiling num-bigint v0.3.2
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]    Compiling num-rational v0.3.2
[INFO] [stderr]     Checking yaml-rust v0.4.5
[INFO] [stderr]     Checking arc-pest v0.4.0
[INFO] [stderr]     Checking num-complex v0.3.1
[INFO] [stderr]     Checking bigdecimal v0.2.0
[INFO] [stderr]     Checking num v0.3.1
[INFO] [stderr]  Documenting arc-rs v0.5.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(box_syntax)]
[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 `arc-rs`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name arc_rs src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="convert"' --cfg 'feature="default"' --cfg 'feature="json"' --cfg 'feature="serde_json"' --cfg 'feature="toml"' --cfg 'feature="yaml"' --cfg 'feature="yaml-rust"' --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern arc_pest=/opt/rustwide/target/debug/deps/libarc_pest-ddb7225cc4304a97.rmeta --extern bigdecimal=/opt/rustwide/target/debug/deps/libbigdecimal-d4b7fcf7ba84c363.rmeta --extern indexmap=/opt/rustwide/target/debug/deps/libindexmap-5183ff54085e1086.rmeta --extern num=/opt/rustwide/target/debug/deps/libnum-b59e064d21d2fe67.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-5678c1422d6b64cb.rmeta --extern serde_json=/opt/rustwide/target/debug/deps/libserde_json-fb1f2d000df2a738.rmeta --extern toml=/opt/rustwide/target/debug/deps/libtoml-218233080ff2ed5a.rmeta --extern yaml_rust=/opt/rustwide/target/debug/deps/libyaml_rust-24992003946a1086.rmeta --cap-lints=warn --crate-version 0.5.1` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "8503927e9b9b71d97f6296bb36276874b650d131b7db6c04f316b07009e2d100", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8503927e9b9b71d97f6296bb36276874b650d131b7db6c04f316b07009e2d100", kill_on_drop: false }`
[INFO] [stdout] 8503927e9b9b71d97f6296bb36276874b650d131b7db6c04f316b07009e2d100
