[INFO] fetching crate drumbeat 0.1.1...
[INFO] documenting drumbeat-0.1.1 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate drumbeat 0.1.1 into /workspace/builds/worker-66/source
[INFO] validating manifest of crates.io crate drumbeat 0.1.1 on toolchain 1.61.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate drumbeat 0.1.1
[INFO] finished tweaking crates.io crate drumbeat 0.1.1
[INFO] tweaked toml for crates.io crate drumbeat 0.1.1 written to /workspace/builds/worker-66/source/Cargo.toml
[INFO] crate crates.io crate drumbeat 0.1.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", 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]  Downloading crates ...
[INFO] [stderr]   Downloaded libc v0.2.89
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-66/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-66/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 976574707a704c825a704d2a507100aabd2533a0368af8615047ef4265b0125e
[INFO] running `Command { std: "docker" "start" "-a" "976574707a704c825a704d2a507100aabd2533a0368af8615047ef4265b0125e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "976574707a704c825a704d2a507100aabd2533a0368af8615047ef4265b0125e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "976574707a704c825a704d2a507100aabd2533a0368af8615047ef4265b0125e", kill_on_drop: false }`
[INFO] [stdout] 976574707a704c825a704d2a507100aabd2533a0368af8615047ef4265b0125e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-66/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-66/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b0e8f6a5b91c25bfc23dcb16083d6f88516ea5c5100af81350f19df894235bce
[INFO] running `Command { std: "docker" "start" "-a" "b0e8f6a5b91c25bfc23dcb16083d6f88516ea5c5100af81350f19df894235bce", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.89
[INFO] [stderr]    Compiling getrandom v0.2.2
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]     Checking ppv-lite86 v0.2.10
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking rand_core v0.6.2
[INFO] [stderr]     Checking rand_chacha v0.3.0
[INFO] [stderr]     Checking rand v0.8.3
[INFO] [stderr]  Documenting drumbeat v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | #![feature(negative_impls)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![feature(async_closure)]
[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] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `drumbeat`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name drumbeat src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=416f08fae0651542 -L dependency=/opt/rustwide/target/debug/deps --extern lazy_static=/opt/rustwide/target/debug/deps/liblazy_static-1479f2b7adeaa2b6.rmeta --extern log=/opt/rustwide/target/debug/deps/liblog-9bc12257f57dd5ae.rmeta --extern num_cpus=/opt/rustwide/target/debug/deps/libnum_cpus-3e6c0e49aaefd7f9.rmeta --extern rand=/opt/rustwide/target/debug/deps/librand-7c10f71217971d3c.rmeta --cap-lints=warn --crate-version 0.1.1` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "b0e8f6a5b91c25bfc23dcb16083d6f88516ea5c5100af81350f19df894235bce", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b0e8f6a5b91c25bfc23dcb16083d6f88516ea5c5100af81350f19df894235bce", kill_on_drop: false }`
[INFO] [stdout] b0e8f6a5b91c25bfc23dcb16083d6f88516ea5c5100af81350f19df894235bce