[INFO] fetching crate drone 0.14.0...
[INFO] documenting drone-0.14.0 against 1.54.0 for beta-1.55-rustdoc-1
[INFO] extracting crate drone 0.14.0 into /workspace/builds/worker-11/source
[INFO] validating manifest of crates.io crate drone 0.14.0 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] removed /workspace/builds/worker-11/source/rust-toolchain
[INFO] started tweaking crates.io crate drone 0.14.0
[INFO] finished tweaking crates.io crate drone 0.14.0
[INFO] tweaked toml for crates.io crate drone 0.14.0 written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate crates.io crate drone 0.14.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded handlebars v3.5.4
[INFO] [stderr]   Downloaded signal-hook v0.2.3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 7e5ea7ca531dae8cc7b7ae2a221deae775ede37925dc9816179088626546e321
[INFO] running `Command { std: "docker" "start" "-a" "7e5ea7ca531dae8cc7b7ae2a221deae775ede37925dc9816179088626546e321", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7e5ea7ca531dae8cc7b7ae2a221deae775ede37925dc9816179088626546e321", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7e5ea7ca531dae8cc7b7ae2a221deae775ede37925dc9816179088626546e321", kill_on_drop: false }`
[INFO] [stdout] 7e5ea7ca531dae8cc7b7ae2a221deae775ede37925dc9816179088626546e321
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] e0d671a8e224b9b833253ca1f8f02bc0ead688452d87256313f2d5e61ae30861
[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" "e0d671a8e224b9b833253ca1f8f02bc0ead688452d87256313f2d5e61ae30861", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.93
[INFO] [stderr]    Compiling serde_derive v1.0.125
[INFO] [stderr]    Compiling serde v1.0.125
[INFO] [stderr]    Compiling getrandom v0.2.2
[INFO] [stderr]    Compiling ucd-trie v0.1.3
[INFO] [stderr]    Compiling maplit v1.0.2
[INFO] [stderr]    Compiling anyhow v1.0.40
[INFO] [stderr]     Checking quick-error v2.0.0
[INFO] [stderr]     Checking humantime v2.1.0
[INFO] [stderr]     Checking csv-core v0.1.10
[INFO] [stderr]    Compiling thiserror-impl v1.0.24
[INFO] [stderr]     Checking Inflector v0.11.4
[INFO] [stderr]    Compiling pest v2.1.3
[INFO] [stderr]    Compiling pest_meta v2.1.3
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking dirs v1.0.5
[INFO] [stderr]     Checking signal-hook-registry v1.3.0
[INFO] [stderr]     Checking term v0.5.2
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking env_logger v0.8.3
[INFO] [stderr]     Checking signal-hook v0.2.3
[INFO] [stderr]     Checking rand_core v0.6.2
[INFO] [stderr]     Checking rand_chacha v0.3.0
[INFO] [stderr]     Checking thiserror v1.0.24
[INFO] [stderr]     Checking rand v0.8.3
[INFO] [stderr]    Compiling pest_generator v2.1.3
[INFO] [stderr]     Checking tempfile v3.2.0
[INFO] [stderr]    Compiling pest_derive v2.1.0
[INFO] [stderr]     Checking structopt v0.3.21
[INFO] [stderr]     Checking bstr v0.2.15
[INFO] [stderr]     Checking serde_json v1.0.64
[INFO] [stderr]     Checking toml v0.5.8
[INFO] [stderr]     Checking csv v1.1.6
[INFO] [stderr]     Checking drone-config v0.14.0
[INFO] [stderr]     Checking handlebars v3.5.4
[INFO] [stderr]     Checking prettytable-rs v0.8.0
[INFO] [stderr]     Checking drone v0.14.0 (/opt/rustwide/workdir)
[INFO] [stderr]  Documenting drone v0.14.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:28:1
[INFO] [stdout]    |
[INFO] [stdout] 28 | #![feature(bool_to_option)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:29:1
[INFO] [stdout]    |
[INFO] [stdout] 29 | #![feature(exhaustive_patterns)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:30:1
[INFO] [stdout]    |
[INFO] [stdout] 30 | #![feature(generator_trait)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:31:1
[INFO] [stdout]    |
[INFO] [stdout] 31 | #![feature(generators)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:32:1
[INFO] [stdout]    |
[INFO] [stdout] 32 | #![feature(never_type)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 6 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 `drone`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name drone 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 inflector=/opt/rustwide/target/debug/deps/libinflector-a888a13d3cd06e62.rmeta --extern ansi_term=/opt/rustwide/target/debug/deps/libansi_term-fd7abddf7181542f.rmeta --extern anyhow=/opt/rustwide/target/debug/deps/libanyhow-ed234740686b5bee.rmeta --extern drone_config=/opt/rustwide/target/debug/deps/libdrone_config-8300257b620bd086.rmeta --extern env_logger=/opt/rustwide/target/debug/deps/libenv_logger-220ad004a88d9786.rmeta --extern handlebars=/opt/rustwide/target/debug/deps/libhandlebars-3c86c44cc7daa8ae.rmeta --extern libc=/opt/rustwide/target/debug/deps/liblibc-e788abd605eda087.rmeta --extern log=/opt/rustwide/target/debug/deps/liblog-f8abb66ffc16068c.rmeta --extern prettytable=/opt/rustwide/target/debug/deps/libprettytable-f31f3f3e0535e566.rmeta --extern regex=/opt/rustwide/target/debug/deps/libregex-6792f3d5f7a30912.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-606330f362a4d5f7.rmeta --extern serde_json=/opt/rustwide/target/debug/deps/libserde_json-c3d7b386ccf22528.rmeta --extern signal_hook=/opt/rustwide/target/debug/deps/libsignal_hook-9ed098852e2a6f72.rmeta --extern structopt=/opt/rustwide/target/debug/deps/libstructopt-8aa870acef4c8bce.rmeta --extern tempfile=/opt/rustwide/target/debug/deps/libtempfile-189822ae6710191e.rmeta --extern thiserror=/opt/rustwide/target/debug/deps/libthiserror-613928fc3282f808.rmeta --extern toml=/opt/rustwide/target/debug/deps/libtoml-da54df4ae32e181c.rmeta --extern walkdir=/opt/rustwide/target/debug/deps/libwalkdir-c0fe0581f7b315ac.rmeta --cap-lints=warn --crate-version 0.14.0` (exit status: 1)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:28:1
[INFO] [stdout]    |
[INFO] [stdout] 28 | #![feature(bool_to_option)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:29:1
[INFO] [stdout]    |
[INFO] [stdout] 29 | #![feature(exhaustive_patterns)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:30:1
[INFO] [stdout]    |
[INFO] [stdout] 30 | #![feature(generator_trait)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:31:1
[INFO] [stdout]    |
[INFO] [stdout] 31 | #![feature(generators)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:32:1
[INFO] [stdout]    |
[INFO] [stdout] 32 | #![feature(never_type)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 5 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "e0d671a8e224b9b833253ca1f8f02bc0ead688452d87256313f2d5e61ae30861", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e0d671a8e224b9b833253ca1f8f02bc0ead688452d87256313f2d5e61ae30861", kill_on_drop: false }`
[INFO] [stdout] e0d671a8e224b9b833253ca1f8f02bc0ead688452d87256313f2d5e61ae30861
