[INFO] fetching crate tarpc-lib 0.7.0...
[INFO] documenting tarpc-lib-0.7.0 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate tarpc-lib 0.7.0 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate tarpc-lib 0.7.0 on toolchain 1.46.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate tarpc-lib 0.7.0
[INFO] finished tweaking crates.io crate tarpc-lib 0.7.0
[INFO] tweaked toml for crates.io crate tarpc-lib 0.7.0 written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--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-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e74ea9c6e3ef2b0a9bf5bf7404c7b9511417ed1eba5dabe26198070474e4d32e
[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" "e74ea9c6e3ef2b0a9bf5bf7404c7b9511417ed1eba5dabe26198070474e4d32e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e74ea9c6e3ef2b0a9bf5bf7404c7b9511417ed1eba5dabe26198070474e4d32e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e74ea9c6e3ef2b0a9bf5bf7404c7b9511417ed1eba5dabe26198070474e4d32e", kill_on_drop: false }`
[INFO] [stdout] e74ea9c6e3ef2b0a9bf5bf7404c7b9511417ed1eba5dabe26198070474e4d32e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", 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] ea4d73a4b677f2572c6726476d2a7eb1415016d1c6967d538587e464da92d0d8
[INFO] running `Command { std: "docker" "start" "-a" "ea4d73a4b677f2572c6726476d2a7eb1415016d1c6967d538587e464da92d0d8", kill_on_drop: false }`
[INFO] [stderr]     Checking futures-channel-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking tarpc-trace v0.3.0
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking tokio-executor v0.2.0-alpha.6
[INFO] [stderr]     Checking tokio-sync v0.2.0-alpha.6
[INFO] [stderr]     Checking futures-executor-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking futures-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking tokio-timer v0.3.0-alpha.6
[INFO] [stderr]  Documenting tarpc-lib v0.7.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:7:1
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![feature(weak_counts, non_exhaustive, trait_alias)]
[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 `tarpc-lib`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name tarpc_lib src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern fnv=/opt/rustwide/target/debug/deps/libfnv-6f83b5744b59dc2d.rmeta --extern futures=/opt/rustwide/target/debug/deps/libfutures-9bb43f0ac4d9435f.rmeta --extern humantime=/opt/rustwide/target/debug/deps/libhumantime-7341e70019fcad1d.rmeta --extern log=/opt/rustwide/target/debug/deps/liblog-958bf2a074a4960f.rmeta --extern pin_utils=/opt/rustwide/target/debug/deps/libpin_utils-f9e49bc7e7f315e9.rmeta --extern rand=/opt/rustwide/target/debug/deps/librand-9de4bdcd0d606d7b.rmeta --extern trace=/opt/rustwide/target/debug/deps/libtarpc_trace-1529f518b3ccff4c.rmeta --extern tokio_timer=/opt/rustwide/target/debug/deps/libtokio_timer-3a7c39e7b1f12928.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "ea4d73a4b677f2572c6726476d2a7eb1415016d1c6967d538587e464da92d0d8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ea4d73a4b677f2572c6726476d2a7eb1415016d1c6967d538587e464da92d0d8", kill_on_drop: false }`
[INFO] [stdout] ea4d73a4b677f2572c6726476d2a7eb1415016d1c6967d538587e464da92d0d8