[INFO] fetching crate teatree 0.0.4...
[INFO] documenting teatree-0.0.4 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate teatree 0.0.4 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate teatree 0.0.4 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 teatree 0.0.4
[INFO] finished tweaking crates.io crate teatree 0.0.4
[INFO] tweaked toml for crates.io crate teatree 0.0.4 written to /workspace/builds/worker-9/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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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] b5acc9f391e9fb38caf92269f6dfc160ebb06df18776f84444659933acf8ef05
[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" "b5acc9f391e9fb38caf92269f6dfc160ebb06df18776f84444659933acf8ef05", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b5acc9f391e9fb38caf92269f6dfc160ebb06df18776f84444659933acf8ef05", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b5acc9f391e9fb38caf92269f6dfc160ebb06df18776f84444659933acf8ef05", kill_on_drop: false }`
[INFO] [stdout] b5acc9f391e9fb38caf92269f6dfc160ebb06df18776f84444659933acf8ef05
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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] [stdout] 6f04a5f3deab39b8599f908df1098b5fac791f551a27ce01bfa1b8a0d47650bd
[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" "6f04a5f3deab39b8599f908df1098b5fac791f551a27ce01bfa1b8a0d47650bd", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking fxhash v0.2.1
[INFO] [stderr]     Checking base64 v0.10.1
[INFO] [stderr]     Checking crossbeam-epoch v0.7.2
[INFO] [stderr]     Checking bytes v0.4.12
[INFO] [stderr]     Checking sha3 v0.7.3
[INFO] [stderr]     Checking zeroize v1.1.0
[INFO] [stderr]     Checking hashbrown v0.3.1
[INFO] [stderr]     Checking serde_urlencoded v0.6.1
[INFO] [stderr]     Checking bincode v1.3.1
[INFO] [stderr]     Checking ed25519 v1.0.1
[INFO] [stderr]     Checking serde_bytes v0.11.5
[INFO] [stderr]     Checking curve25519-dalek v3.0.0
[INFO] [stderr]     Checking tokio-io v0.1.13
[INFO] [stderr]     Checking http v0.1.21
[INFO] [stderr]     Checking string v0.2.1
[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 pagecache v0.17.0
[INFO] [stderr]     Checking actix-codec v0.1.2
[INFO] [stderr]     Checking ed25519-dalek v1.0.0
[INFO] [stderr]     Checking actix-utils v0.4.7
[INFO] [stderr]     Checking tokio-tcp v0.1.4
[INFO] [stderr]     Checking tokio-udp v0.1.6
[INFO] [stderr]     Checking actix-rt v0.2.6
[INFO] [stderr]     Checking tokio-uds v0.2.7
[INFO] [stderr]     Checking actix-server-config v0.1.2
[INFO] [stderr]     Checking trust-dns-proto v0.7.4
[INFO] [stderr]     Checking tokio v0.1.22
[INFO] [stderr]     Checking h2 v0.1.26
[INFO] [stderr]     Checking jsonrpc-parse v0.1.2
[INFO] [stderr]     Checking trust-dns-resolver v0.11.1
[INFO] [stderr]     Checking sled v0.24.1
[INFO] [stderr]     Checking actix-connect v0.2.5
[INFO] [stderr]     Checking actix-http v0.2.11
[INFO] [stderr]     Checking actix v0.8.3
[INFO] [stderr]  Documenting teatree v0.0.4 (/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(vec_drain_as_slice)]
[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 `teatree`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name teatree 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 actix=/opt/rustwide/target/debug/deps/libactix-8f72f63ea9a6ae1f.rmeta --extern actix_derive=/opt/rustwide/target/debug/deps/libactix_derive-e192d722a2a1d938.so --extern bincode=/opt/rustwide/target/debug/deps/libbincode-870f32e9e4909d28.rmeta --extern byteorder=/opt/rustwide/target/debug/deps/libbyteorder-af30f867a78f5aec.rmeta --extern bytes=/opt/rustwide/target/debug/deps/libbytes-497dd1f2a861a24f.rmeta --extern dirs=/opt/rustwide/target/debug/deps/libdirs-7e64f6dca7ea7b5c.rmeta --extern ed25519_dalek=/opt/rustwide/target/debug/deps/libed25519_dalek-642d7aabee39acfe.rmeta --extern failure=/opt/rustwide/target/debug/deps/libfailure-d9fcd1e065ee1e23.rmeta --extern futures=/opt/rustwide/target/debug/deps/libfutures-29a973654112bb9d.rmeta --extern jsonrpc_parse=/opt/rustwide/target/debug/deps/libjsonrpc_parse-7cdd4d7ffa77ad8c.rmeta --extern rand=/opt/rustwide/target/debug/deps/librand-9b356e0eb33fe2d1.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-cf2a7db764a470fc.rmeta --extern serde_derive=/opt/rustwide/target/debug/deps/libserde_derive-3af9a6345491720f.so --extern serde_json=/opt/rustwide/target/debug/deps/libserde_json-00b105e50b749454.rmeta --extern sha3=/opt/rustwide/target/debug/deps/libsha3-011059795bbe3597.rmeta --extern sled=/opt/rustwide/target/debug/deps/libsled-90c74102b5b1570e.rmeta --extern tokio=/opt/rustwide/target/debug/deps/libtokio-d01bcda763bfd3db.rmeta --extern toml=/opt/rustwide/target/debug/deps/libtoml-e384bfc0f0cd205c.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "6f04a5f3deab39b8599f908df1098b5fac791f551a27ce01bfa1b8a0d47650bd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6f04a5f3deab39b8599f908df1098b5fac791f551a27ce01bfa1b8a0d47650bd", kill_on_drop: false }`
[INFO] [stdout] 6f04a5f3deab39b8599f908df1098b5fac791f551a27ce01bfa1b8a0d47650bd