[INFO] fetching crate anchors 0.6.0...
[INFO] documenting anchors-0.6.0 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate anchors 0.6.0 into /workspace/builds/worker-70/source
[INFO] validating manifest of crates.io crate anchors 0.6.0 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 anchors 0.6.0
[INFO] finished tweaking crates.io crate anchors 0.6.0
[INFO] tweaked toml for crates.io crate anchors 0.6.0 written to /workspace/builds/worker-70/source/Cargo.toml
[INFO] crate crates.io crate anchors 0.6.0 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]  Downloading crates ...
[INFO] [stderr]   Downloaded byteorder v1.4.2
[INFO] [stderr]   Downloaded serde v1.0.123
[INFO] [stderr]   Downloaded rand_xoshiro v0.4.0
[INFO] [stderr]   Downloaded serde_derive v1.0.123
[INFO] [stderr]   Downloaded arena-graph v0.1.0
[INFO] [stderr]   Downloaded im v15.0.0
[INFO] [stderr]   Downloaded serde_json v1.0.63
[INFO] [stderr]   Downloaded tinytemplate v1.2.0
[INFO] [stderr]   Downloaded sized-chunks v0.6.4
[INFO] [stderr]   Downloaded plotters v0.3.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-70/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-70/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] ea56af0d489c00cfb1ebc9b06546f46363c0700b7dd89053afc8c289599412ea
[INFO] running `Command { std: "docker" "start" "-a" "ea56af0d489c00cfb1ebc9b06546f46363c0700b7dd89053afc8c289599412ea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ea56af0d489c00cfb1ebc9b06546f46363c0700b7dd89053afc8c289599412ea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ea56af0d489c00cfb1ebc9b06546f46363c0700b7dd89053afc8c289599412ea", kill_on_drop: false }`
[INFO] [stdout] ea56af0d489c00cfb1ebc9b06546f46363c0700b7dd89053afc8c289599412ea
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-70/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-70/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] f88f9f22a028c5ee5edf26d9037a6494d83541e6b2061af510dfdfc0b894562c
[INFO] running `Command { std: "docker" "start" "-a" "f88f9f22a028c5ee5edf26d9037a6494d83541e6b2061af510dfdfc0b894562c", kill_on_drop: false }`
[INFO] [stderr]    Compiling typenum v1.12.0
[INFO] [stderr]    Compiling version_check v0.9.2
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking typed-arena v2.0.1
[INFO] [stderr]     Checking rand_xoshiro v0.4.0
[INFO] [stderr]     Checking arena-graph v0.1.0
[INFO] [stderr]    Compiling im v15.0.0
[INFO] [stderr]     Checking bitmaps v2.1.0
[INFO] [stderr]     Checking sized-chunks v0.6.4
[INFO] [stderr]  Documenting anchors v0.6.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(negative_impls)]
[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 `anchors`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name anchors src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=aac92163a856a6cc -L dependency=/opt/rustwide/target/debug/deps --extern arena_graph=/opt/rustwide/target/debug/deps/libarena_graph-133b6ccb01e12105.rmeta --extern im=/opt/rustwide/target/debug/deps/libim-b74cce9f79392d6b.rmeta --extern typed_arena=/opt/rustwide/target/debug/deps/libtyped_arena-98b69d4343ee48c9.rmeta --cap-lints=warn --crate-version 0.6.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "f88f9f22a028c5ee5edf26d9037a6494d83541e6b2061af510dfdfc0b894562c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f88f9f22a028c5ee5edf26d9037a6494d83541e6b2061af510dfdfc0b894562c", kill_on_drop: false }`
[INFO] [stdout] f88f9f22a028c5ee5edf26d9037a6494d83541e6b2061af510dfdfc0b894562c