[INFO] fetching crate tower-opentelemetry 0.2.0-beta.1...
[INFO] documenting tower-opentelemetry-0.2.0-beta.1 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate tower-opentelemetry 0.2.0-beta.1 into /workspace/builds/worker-13/source
[INFO] validating manifest of crates.io crate tower-opentelemetry 0.2.0-beta.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 tower-opentelemetry 0.2.0-beta.1
[INFO] finished tweaking crates.io crate tower-opentelemetry 0.2.0-beta.1
[INFO] tweaked toml for crates.io crate tower-opentelemetry 0.2.0-beta.1 written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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]  Downloading crates ...
[INFO] [stderr]   Downloaded opentelemetry-semantic-conventions v0.9.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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] a118544a1fd2a03b189101cdb6fc7e455bda0d2cb13d85f0968cf42412cbd8f2
[INFO] running `Command { std: "docker" "start" "-a" "a118544a1fd2a03b189101cdb6fc7e455bda0d2cb13d85f0968cf42412cbd8f2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a118544a1fd2a03b189101cdb6fc7e455bda0d2cb13d85f0968cf42412cbd8f2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a118544a1fd2a03b189101cdb6fc7e455bda0d2cb13d85f0968cf42412cbd8f2", kill_on_drop: false }`
[INFO] [stdout] a118544a1fd2a03b189101cdb6fc7e455bda0d2cb13d85f0968cf42412cbd8f2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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] 1654dda94a6495b790875da2cbcc71df0beed98aab70351b1d9b48afad4fd2d4
[INFO] running `Command { std: "docker" "start" "-a" "1654dda94a6495b790875da2cbcc71df0beed98aab70351b1d9b48afad4fd2d4", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.95
[INFO] [stderr]    Compiling crossbeam-utils v0.8.8
[INFO] [stderr]    Compiling futures-util v0.3.21
[INFO] [stderr]    Compiling rayon-core v1.9.3
[INFO] [stderr]     Checking futures-sink v0.3.21
[INFO] [stderr]    Compiling futures-channel v0.3.21
[INFO] [stderr]     Checking either v1.6.1
[INFO] [stderr]    Compiling sysinfo v0.23.13
[INFO] [stderr]     Checking bytes v1.1.0
[INFO] [stderr]     Checking tower-layer v0.3.1
[INFO] [stderr]     Checking tower-service v0.3.1
[INFO] [stderr]    Compiling memoffset v0.6.5
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.8
[INFO] [stderr]    Compiling rayon v1.5.3
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking http v0.2.7
[INFO] [stderr]     Checking crossbeam-channel v0.5.4
[INFO] [stderr]     Checking crossbeam-deque v0.8.1
[INFO] [stderr]    Compiling futures-macro v0.3.21
[INFO] [stderr]    Compiling thiserror-impl v1.0.31
[INFO] [stderr]    Compiling pin-project-internal v1.0.10
[INFO] [stderr]    Compiling async-trait v0.1.53
[INFO] [stderr]     Checking pin-project v1.0.10
[INFO] [stderr]     Checking thiserror v1.0.31
[INFO] [stderr]     Checking futures-executor v0.3.21
[INFO] [stderr]     Checking opentelemetry v0.17.0
[INFO] [stderr]     Checking opentelemetry-semantic-conventions v0.9.0
[INFO] [stderr]  Documenting tower-opentelemetry v0.2.0-beta.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(backtrace)]
[INFO] [stdout]   |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unresolved link to `TraceLayer`
[INFO] [stdout]   --> src/lib.rs:64:24
[INFO] [stdout]    |
[INFO] [stdout] 64 |     /// Create a new [`TraceLayer`] using the given [`MakeClassifier`].
[INFO] [stdout]    |                        ^^^^^^^^^^ no item named `TraceLayer` in scope
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default
[INFO] [stdout]    = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unresolved link to `MakeClassifier`
[INFO] [stdout]   --> src/lib.rs:64:55
[INFO] [stdout]    |
[INFO] [stdout] 64 |     /// Create a new [`TraceLayer`] using the given [`MakeClassifier`].
[INFO] [stdout]    |                                                       ^^^^^^^^^^^^^^ no item named `MakeClassifier` in scope
[INFO] [stdout]    |
[INFO] [stdout]    = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `tower-opentelemetry`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name tower_opentelemetry src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=70cb68ae368423e0 -L dependency=/opt/rustwide/target/debug/deps --extern futures_util=/opt/rustwide/target/debug/deps/libfutures_util-363e6a3bbc9a83ab.rmeta --extern http=/opt/rustwide/target/debug/deps/libhttp-679a46388cba1084.rmeta --extern lazy_static=/opt/rustwide/target/debug/deps/liblazy_static-1479f2b7adeaa2b6.rmeta --extern opentelemetry=/opt/rustwide/target/debug/deps/libopentelemetry-12010b2ce3fb19a7.rmeta --extern opentelemetry_semantic_conventions=/opt/rustwide/target/debug/deps/libopentelemetry_semantic_conventions-bc38b2a5d5289eac.rmeta --extern sysinfo=/opt/rustwide/target/debug/deps/libsysinfo-f2d85edbbda87ad7.rmeta --extern tower_layer=/opt/rustwide/target/debug/deps/libtower_layer-45359bca8c554c9a.rmeta --extern tower_service=/opt/rustwide/target/debug/deps/libtower_service-3730c7375171f9fc.rmeta --cap-lints=warn --crate-version 0.2.0-beta.1` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "1654dda94a6495b790875da2cbcc71df0beed98aab70351b1d9b48afad4fd2d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1654dda94a6495b790875da2cbcc71df0beed98aab70351b1d9b48afad4fd2d4", kill_on_drop: false }`
[INFO] [stdout] 1654dda94a6495b790875da2cbcc71df0beed98aab70351b1d9b48afad4fd2d4