[INFO] fetching crate lark-debug-with 0.1.0...
[INFO] documenting lark-debug-with-0.1.0 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate lark-debug-with 0.1.0 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate lark-debug-with 0.1.0 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 lark-debug-with 0.1.0
[INFO] finished tweaking crates.io crate lark-debug-with 0.1.0
[INFO] tweaked toml for crates.io crate lark-debug-with 0.1.0 written to /workspace/builds/worker-0/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-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] [stdout] 5f7b41ff6b86c67d39dfd1f2d354cf6d474a02569e5561ae1737f5dae09f8b0c
[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" "5f7b41ff6b86c67d39dfd1f2d354cf6d474a02569e5561ae1737f5dae09f8b0c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5f7b41ff6b86c67d39dfd1f2d354cf6d474a02569e5561ae1737f5dae09f8b0c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5f7b41ff6b86c67d39dfd1f2d354cf6d474a02569e5561ae1737f5dae09f8b0c", kill_on_drop: false }`
[INFO] [stdout] 5f7b41ff6b86c67d39dfd1f2d354cf6d474a02569e5561ae1737f5dae09f8b0c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] fc0edc0b07777d86f0d3224cc49982a79ef5cfd482d47d5fc5344923f6298914
[INFO] running `Command { std: "docker" "start" "-a" "fc0edc0b07777d86f0d3224cc49982a79ef5cfd482d47d5fc5344923f6298914", kill_on_drop: false }`
[INFO] [stderr]  Documenting lark-debug-with v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![feature(box_patterns)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:7:1
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![feature(never_type)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:8:1
[INFO] [stdout]   |
[INFO] [stdout] 8 | #![feature(in_band_lifetimes)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | #![feature(specialization)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 5 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 `lark-debug-with`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name lark_debug_with 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 indexmap=/opt/rustwide/target/debug/deps/libindexmap-1a7a9a0db5c92fc6.rmeta --cap-lints=warn --crate-version 0.1.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "fc0edc0b07777d86f0d3224cc49982a79ef5cfd482d47d5fc5344923f6298914", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fc0edc0b07777d86f0d3224cc49982a79ef5cfd482d47d5fc5344923f6298914", kill_on_drop: false }`
[INFO] [stdout] fc0edc0b07777d86f0d3224cc49982a79ef5cfd482d47d5fc5344923f6298914