[INFO] fetching crate fifo 0.2.0...
[INFO] documenting fifo-0.2.0 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate fifo 0.2.0 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate fifo 0.2.0 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 fifo 0.2.0
[INFO] finished tweaking crates.io crate fifo 0.2.0
[INFO] tweaked toml for crates.io crate fifo 0.2.0 written to /workspace/builds/worker-3/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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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] 751df9bde9911f4493fca0815fd26b3673e2057f8d116c5bc2b54e26c0f57244
[INFO] running `Command { std: "docker" "start" "-a" "751df9bde9911f4493fca0815fd26b3673e2057f8d116c5bc2b54e26c0f57244", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "751df9bde9911f4493fca0815fd26b3673e2057f8d116c5bc2b54e26c0f57244", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "751df9bde9911f4493fca0815fd26b3673e2057f8d116c5bc2b54e26c0f57244", kill_on_drop: false }`
[INFO] [stdout] 751df9bde9911f4493fca0815fd26b3673e2057f8d116c5bc2b54e26c0f57244
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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] 84efb8c08a489846d5299047c4dfc5805e760655ecd104909ef96c98c1796fc3
[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" "84efb8c08a489846d5299047c4dfc5805e760655ecd104909ef96c98c1796fc3", kill_on_drop: false }`
[INFO] [stderr]  Documenting fifo v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0432]: unresolved import `alloc::heap`
[INFO] [stdout]   --> src/lib.rs:30:5
[INFO] [stdout]    |
[INFO] [stdout] 30 | use alloc::heap;
[INFO] [stdout]    |     ^^^^^^^^^^^ no `heap` in the root
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:21:1
[INFO] [stdout]    |
[INFO] [stdout] 21 | #![feature(alloc, heap_api)]
[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:22:1
[INFO] [stdout]    |
[INFO] [stdout] 22 | #![feature(optin_builtin_traits)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: negative trait bounds are not yet fully implemented; use marker types for now
[INFO] [stdout]    --> src/lib.rs:118:6
[INFO] [stdout]     |
[INFO] [stdout] 118 | impl !Sync for Sender {}
[INFO] [stdout]     |      ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: see issue #68318 <https://github.com/rust-lang/rust/issues/68318> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: negative trait bounds are not yet fully implemented; use marker types for now
[INFO] [stdout]    --> src/lib.rs:119:6
[INFO] [stdout]     |
[INFO] [stdout] 119 | impl !Sync for Receiver {}
[INFO] [stdout]     |      ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: see issue #68318 <https://github.com/rust-lang/rust/issues/68318> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 6 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0432, E0554, E0658.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `fifo`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name fifo 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 --cap-lints=warn --crate-version 0.2.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "84efb8c08a489846d5299047c4dfc5805e760655ecd104909ef96c98c1796fc3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "84efb8c08a489846d5299047c4dfc5805e760655ecd104909ef96c98c1796fc3", kill_on_drop: false }`
[INFO] [stdout] 84efb8c08a489846d5299047c4dfc5805e760655ecd104909ef96c98c1796fc3