[INFO] fetching crate byml 0.1.0...
[INFO] documenting byml-0.1.0 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate byml 0.1.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate byml 0.1.0 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 byml 0.1.0
[INFO] finished tweaking crates.io crate byml 0.1.0
[INFO] tweaked toml for crates.io crate byml 0.1.0 written to /workspace/builds/worker-4/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-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] 910d8eef0562fad5d8f84193ef855150e409e3d74cd85404589c90dd9d3ad218
[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" "910d8eef0562fad5d8f84193ef855150e409e3d74cd85404589c90dd9d3ad218", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "910d8eef0562fad5d8f84193ef855150e409e3d74cd85404589c90dd9d3ad218", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "910d8eef0562fad5d8f84193ef855150e409e3d74cd85404589c90dd9d3ad218", kill_on_drop: false }`
[INFO] [stdout] 910d8eef0562fad5d8f84193ef855150e409e3d74cd85404589c90dd9d3ad218
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] 605b815bcd86cfa63211dd306d02bd1a7894250e7610f95b06f7a35c2575a732
[INFO] running `Command { std: "docker" "start" "-a" "605b815bcd86cfa63211dd306d02bd1a7894250e7610f95b06f7a35c2575a732", kill_on_drop: false }`
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]     Checking nodrop v0.1.14
[INFO] [stderr]    Compiling paste-impl v0.1.18
[INFO] [stderr]    Compiling binread_derive v1.1.0
[INFO] [stderr]    Compiling binwrite_derive v0.2.1
[INFO] [stderr]     Checking parse_int v0.4.0
[INFO] [stderr]     Checking paste v0.1.18
[INFO] [stderr]     Checking yaz0 v0.1.2
[INFO] [stderr]     Checking binwrite v0.2.1
[INFO] [stderr]     Checking binread v1.1.1
[INFO] [stderr]  Documenting byml v0.1.0 (/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(seek_convenience)]
[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 `byml`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name byml 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 base64=/opt/rustwide/target/debug/deps/libbase64-776a35e3368273cb.rmeta --extern binread=/opt/rustwide/target/debug/deps/libbinread-9f0d94e86ca33038.rmeta --extern binwrite=/opt/rustwide/target/debug/deps/libbinwrite-2a8d6a0b3ab0eed0.rmeta --extern byteorder=/opt/rustwide/target/debug/deps/libbyteorder-cdbbc07100f440a1.rmeta --extern indexmap=/opt/rustwide/target/debug/deps/libindexmap-a0b6c0739e0c898d.rmeta --extern parse_int=/opt/rustwide/target/debug/deps/libparse_int-533cab6ab11d4239.rmeta --extern yaz0=/opt/rustwide/target/debug/deps/libyaz0-021dc842df3e9ef6.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "605b815bcd86cfa63211dd306d02bd1a7894250e7610f95b06f7a35c2575a732", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "605b815bcd86cfa63211dd306d02bd1a7894250e7610f95b06f7a35c2575a732", kill_on_drop: false }`
[INFO] [stdout] 605b815bcd86cfa63211dd306d02bd1a7894250e7610f95b06f7a35c2575a732