[INFO] fetching crate kapiti 0.0.1...
[INFO] documenting kapiti-0.0.1 against 1.54.0 for beta-1.55-rustdoc-1
[INFO] extracting crate kapiti 0.0.1 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate kapiti 0.0.1 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 kapiti 0.0.1
[INFO] finished tweaking crates.io crate kapiti 0.0.1
[INFO] tweaked toml for crates.io crate kapiti 0.0.1 written to /workspace/builds/worker-5/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-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] f26a6b3c4e90f1a62534c63b705c098994bddc12d5af15e98cd1bf7e012e82a9
[INFO] running `Command { std: "docker" "start" "-a" "f26a6b3c4e90f1a62534c63b705c098994bddc12d5af15e98cd1bf7e012e82a9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f26a6b3c4e90f1a62534c63b705c098994bddc12d5af15e98cd1bf7e012e82a9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f26a6b3c4e90f1a62534c63b705c098994bddc12d5af15e98cd1bf7e012e82a9", kill_on_drop: false }`
[INFO] [stdout] f26a6b3c4e90f1a62534c63b705c098994bddc12d5af15e98cd1bf7e012e82a9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] f8ad933b76b6949fc2bbf12cb0bb869b6f7bc1028595392c7965514d447abfe3
[INFO] running `Command { std: "docker" "start" "-a" "f8ad933b76b6949fc2bbf12cb0bb869b6f7bc1028595392c7965514d447abfe3", kill_on_drop: false }`
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.17
[INFO] [stderr]     Checking tokio-executor v0.2.0-alpha.1
[INFO] [stderr]    Compiling protobuf v2.25.0
[INFO] [stderr]    Compiling bytes v1.0.1
[INFO] [stderr]    Compiling regex-automata v0.1.10
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling itoa v0.4.7
[INFO] [stderr]     Checking crossbeam-utils v0.6.6
[INFO] [stderr]     Checking tracing-core v0.1.18
[INFO] [stderr]     Checking mio v0.6.23
[INFO] [stderr]    Compiling csv-core v0.1.10
[INFO] [stderr]    Compiling serde v1.0.127
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.17
[INFO] [stderr]     Checking tokio-io v0.2.0-alpha.1
[INFO] [stderr]     Checking crossbeam-queue v0.1.2
[INFO] [stderr]     Checking crossbeam-channel v0.3.9
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.17
[INFO] [stderr]     Checking tokio-codec v0.2.0-alpha.1
[INFO] [stderr]     Checking mio-uds v0.6.8
[INFO] [stderr]     Checking tokio-current-thread v0.2.0-alpha.1
[INFO] [stderr]     Checking tokio-sync v0.2.0-alpha.1
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/tokio-sync-0.2.0-alpha.1/src/lib.rs:10:1
[INFO] [stdout]    |
[INFO] [stdout] 10 | #![feature(async_await)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]    |
[INFO] [stdout]    = help: the feature `async_await` has been stable since 1.39.0 and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `tokio-sync`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "f8ad933b76b6949fc2bbf12cb0bb869b6f7bc1028595392c7965514d447abfe3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f8ad933b76b6949fc2bbf12cb0bb869b6f7bc1028595392c7965514d447abfe3", kill_on_drop: false }`
[INFO] [stdout] f8ad933b76b6949fc2bbf12cb0bb869b6f7bc1028595392c7965514d447abfe3
