[INFO] fetching crate perf_monitor 0.2.0...
[INFO] documenting perf_monitor-0.2.0 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate perf_monitor 0.2.0 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate perf_monitor 0.2.0 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 perf_monitor 0.2.0
[INFO] finished tweaking crates.io crate perf_monitor 0.2.0
[INFO] tweaked toml for crates.io crate perf_monitor 0.2.0 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate crates.io crate perf_monitor 0.2.0 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 thread_local v1.1.2
[INFO] [stderr]   Downloaded clang-sys v1.1.1
[INFO] [stderr]   Downloaded bindgen v0.55.1
[INFO] [stderr]   Downloaded lpfs v0.2.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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] 6397ed17548624cffc8b9cebfb25b7e013ed147bdfca2cb3808da1b7eef7047c
[INFO] running `Command { std: "docker" "start" "-a" "6397ed17548624cffc8b9cebfb25b7e013ed147bdfca2cb3808da1b7eef7047c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6397ed17548624cffc8b9cebfb25b7e013ed147bdfca2cb3808da1b7eef7047c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6397ed17548624cffc8b9cebfb25b7e013ed147bdfca2cb3808da1b7eef7047c", kill_on_drop: false }`
[INFO] [stdout] 6397ed17548624cffc8b9cebfb25b7e013ed147bdfca2cb3808da1b7eef7047c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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] a38616854ed71f1c3c74809e870291761ee9ce71e3d12450c4577b3999c77ec3
[INFO] running `Command { std: "docker" "start" "-a" "a38616854ed71f1c3c74809e870291761ee9ce71e3d12450c4577b3999c77ec3", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.85
[INFO] [stderr]    Compiling memchr v2.3.4
[INFO] [stderr]    Compiling version_check v0.9.3
[INFO] [stderr]    Compiling once_cell v1.5.2
[INFO] [stderr]    Compiling unicode-width v0.1.8
[INFO] [stderr]    Compiling quick-error v1.2.3
[INFO] [stderr]    Compiling regex-syntax v0.6.22
[INFO] [stderr]    Compiling bindgen v0.55.1
[INFO] [stderr]    Compiling termcolor v1.1.2
[INFO] [stderr]    Compiling vec_map v0.8.2
[INFO] [stderr]    Compiling syn v1.0.60
[INFO] [stderr]    Compiling ansi_term v0.11.0
[INFO] [stderr]    Compiling strsim v0.8.0
[INFO] [stderr]    Compiling shlex v0.1.1
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]    Compiling cc v1.0.66
[INFO] [stderr]     Checking futures v0.1.30
[INFO] [stderr]     Checking lpfs v0.2.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling clang-sys v1.1.1
[INFO] [stderr]    Compiling libloading v0.7.0
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]     Checking lock_api v0.3.4
[INFO] [stderr]    Compiling humantime v1.3.0
[INFO] [stderr]    Compiling textwrap v0.11.0
[INFO] [stderr]    Compiling thread_local v1.1.2
[INFO] [stderr]    Compiling nom v5.1.2
[INFO] [stderr]    Compiling quote v1.0.8
[INFO] [stderr]    Compiling aho-corasick v0.7.15
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling which v3.1.1
[INFO] [stderr]     Checking parking_lot_core v0.7.2
[INFO] [stderr]     Checking errno v0.2.7
[INFO] [stderr]    Compiling clap v2.33.3
[INFO] [stderr]     Checking parking_lot v0.10.2
[INFO] [stderr]    Compiling regex v1.4.3
[INFO] [stderr]    Compiling cexpr v0.4.0
[INFO] [stderr]    Compiling thiserror-impl v1.0.23
[INFO] [stderr]    Compiling env_logger v0.7.1
[INFO] [stderr]     Checking thiserror v1.0.23
[INFO] [stderr]    Compiling perf_monitor v0.2.0 (/opt/rustwide/workdir)
[INFO] [stderr]  Documenting perf_monitor v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:6:18
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![cfg_attr(doc, feature(doc_cfg))]
[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 `perf_monitor`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name perf_monitor src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=93cf0c35d8dfb18a -L dependency=/opt/rustwide/target/debug/deps --extern errno=/opt/rustwide/target/debug/deps/liberrno-41e3de38f3947f49.rmeta --extern futures=/opt/rustwide/target/debug/deps/libfutures-8c1446d8ad1d17e8.rmeta --extern libc=/opt/rustwide/target/debug/deps/liblibc-2da7ed421d69107e.rmeta --extern lpfs=/opt/rustwide/target/debug/deps/liblpfs-f3af14dfacffd50a.rmeta --extern parking_lot=/opt/rustwide/target/debug/deps/libparking_lot-e4751408b3ca85c5.rmeta --extern thiserror=/opt/rustwide/target/debug/deps/libthiserror-de096b353d1a8356.rmeta --cap-lints=warn --crate-version 0.2.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "a38616854ed71f1c3c74809e870291761ee9ce71e3d12450c4577b3999c77ec3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a38616854ed71f1c3c74809e870291761ee9ce71e3d12450c4577b3999c77ec3", kill_on_drop: false }`
[INFO] [stdout] a38616854ed71f1c3c74809e870291761ee9ce71e3d12450c4577b3999c77ec3