[INFO] fetching crate fb_futures_ext 0.1.2...
[INFO] documenting fb_futures_ext-0.1.2 against 1.54.0 for beta-1.55-rustdoc-1
[INFO] extracting crate fb_futures_ext 0.1.2 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate fb_futures_ext 0.1.2 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 fb_futures_ext 0.1.2
[INFO] finished tweaking crates.io crate fb_futures_ext 0.1.2
[INFO] tweaked toml for crates.io crate fb_futures_ext 0.1.2 written to /workspace/builds/worker-0/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] 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] 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" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d138a658bb5690b299ae846eaa29505ac3564d36fd5153fa9024bc927599fbcb
[INFO] running `Command { std: "docker" "start" "-a" "d138a658bb5690b299ae846eaa29505ac3564d36fd5153fa9024bc927599fbcb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d138a658bb5690b299ae846eaa29505ac3564d36fd5153fa9024bc927599fbcb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d138a658bb5690b299ae846eaa29505ac3564d36fd5153fa9024bc927599fbcb", kill_on_drop: false }`
[INFO] [stdout] d138a658bb5690b299ae846eaa29505ac3564d36fd5153fa9024bc927599fbcb
[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" "+1.54.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d8764b37b795dfb744f57823f98f96c58c63defc7f1e78df0d299166135b40db
[INFO] running `Command { std: "docker" "start" "-a" "d8764b37b795dfb744f57823f98f96c58c63defc7f1e78df0d299166135b40db", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.127
[INFO] [stderr]     Checking bytes v0.4.12
[INFO] [stderr]     Checking tokio-io v0.1.13
[INFO] [stderr]     Checking tokio-reactor v0.1.12
[INFO] [stderr]     Checking tokio-codec v0.1.2
[INFO] [stderr]     Checking tokio-fs v0.1.7
[INFO] [stderr]     Checking tokio-uds v0.2.7
[INFO] [stderr]     Checking tokio-tcp v0.1.4
[INFO] [stderr]     Checking tokio-udp v0.1.6
[INFO] [stderr]     Checking tokio v0.1.22
[INFO] [stderr]  Documenting fb_futures_ext v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:11:1
[INFO] [stdout]    |
[INFO] [stdout] 11 | #![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 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 `fb_futures_ext`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name futures_ext 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 anyhow=/opt/rustwide/target/debug/deps/libanyhow-c71486e08dde7454.rmeta --extern bytes_old=/opt/rustwide/target/debug/deps/libbytes-6c9de2868f2a3815.rmeta --extern futures=/opt/rustwide/target/debug/deps/libfutures-533cf53875604e8f.rmeta --extern tokio=/opt/rustwide/target/debug/deps/libtokio-57a4ce277cfada61.rmeta --extern tokio_io=/opt/rustwide/target/debug/deps/libtokio_io-191ea2f132c788d3.rmeta --extern tokio_threadpool=/opt/rustwide/target/debug/deps/libtokio_threadpool-49b748afefec2b44.rmeta --cap-lints=warn --crate-version 0.1.2` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "d8764b37b795dfb744f57823f98f96c58c63defc7f1e78df0d299166135b40db", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d8764b37b795dfb744f57823f98f96c58c63defc7f1e78df0d299166135b40db", kill_on_drop: false }`
[INFO] [stdout] d8764b37b795dfb744f57823f98f96c58c63defc7f1e78df0d299166135b40db
