[INFO] fetching crate yamlate 0.1.1...
[INFO] documenting yamlate-0.1.1 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate yamlate 0.1.1 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate yamlate 0.1.1 on toolchain beta-2020-08-29
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate yamlate 0.1.1
[INFO] finished tweaking crates.io crate yamlate 0.1.1
[INFO] tweaked toml for crates.io crate yamlate 0.1.1 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "+beta-2020-08-29" "metadata" "--no-deps" "--format-version=1", 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] 25a5e62e596528b8e6c3a37c55720a115a2a4a74e99c5395dfe62fb07afbdd30
[INFO] running `Command { std: "docker" "start" "-a" "25a5e62e596528b8e6c3a37c55720a115a2a4a74e99c5395dfe62fb07afbdd30", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "25a5e62e596528b8e6c3a37c55720a115a2a4a74e99c5395dfe62fb07afbdd30", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "25a5e62e596528b8e6c3a37c55720a115a2a4a74e99c5395dfe62fb07afbdd30", kill_on_drop: false }`
[INFO] [stdout] 25a5e62e596528b8e6c3a37c55720a115a2a4a74e99c5395dfe62fb07afbdd30
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 440b066b845deb659d4540c13e34c43634a3c552f107d85a12fb07c31d106527
[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" "440b066b845deb659d4540c13e34c43634a3c552f107d85a12fb07c31d106527", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]     Checking num-integer v0.1.43
[INFO] [stderr]     Checking num-complex v0.3.0
[INFO] [stderr]     Checking num-bigint v0.3.0
[INFO] [stderr]     Checking num-iter v0.1.41
[INFO] [stderr]     Checking num-rational v0.3.0
[INFO] [stderr]     Checking num v0.3.0
[INFO] [stderr]  Documenting yamlate v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(custom_attribute)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: removed in favor of `#![register_tool]` and `#![register_attr]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(custom_attribute)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0557.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `yamlate`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type dylib --crate-name yamlate 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 lazy_static=/opt/rustwide/target/debug/deps/liblazy_static-db88f49d9e5662e7.rmeta --extern libc=/opt/rustwide/target/debug/deps/liblibc-b01e5f49cd1b74e8.rmeta --extern num=/opt/rustwide/target/debug/deps/libnum-f4a5c9b7cc783c95.rmeta --extern yaml_rust=/opt/rustwide/target/debug/deps/libyaml_rust-477942c49c77f6fc.rmeta --cap-lints=warn --crate-version 0.1.1` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "440b066b845deb659d4540c13e34c43634a3c552f107d85a12fb07c31d106527", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "440b066b845deb659d4540c13e34c43634a3c552f107d85a12fb07c31d106527", kill_on_drop: false }`
[INFO] [stdout] 440b066b845deb659d4540c13e34c43634a3c552f107d85a12fb07c31d106527