[INFO] fetching crate canonical 0.7.1...
[INFO] documenting canonical-0.7.1 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate canonical 0.7.1 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate canonical 0.7.1 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 canonical 0.7.1
[INFO] finished tweaking crates.io crate canonical 0.7.1
[INFO] tweaked toml for crates.io crate canonical 0.7.1 written to /workspace/builds/worker-0/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] [stderr]     Blocking waiting for file lock on package cache
[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 canonical_derive v0.7.0
[INFO] [stderr]   Downloaded canonical_fuzz v0.7.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] c8cbe3a6f665541c11e5e6f2d890e6451db2b228216d260254514fae22354f22
[INFO] running `Command { std: "docker" "start" "-a" "c8cbe3a6f665541c11e5e6f2d890e6451db2b228216d260254514fae22354f22", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c8cbe3a6f665541c11e5e6f2d890e6451db2b228216d260254514fae22354f22", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c8cbe3a6f665541c11e5e6f2d890e6451db2b228216d260254514fae22354f22", kill_on_drop: false }`
[INFO] [stdout] c8cbe3a6f665541c11e5e6f2d890e6451db2b228216d260254514fae22354f22
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] 294428e8df020088e3e4340cb1476aedfa23ce7041d05c342c2c3d792d502ed7
[INFO] running `Command { std: "docker" "start" "-a" "294428e8df020088e3e4340cb1476aedfa23ce7041d05c342c2c3d792d502ed7", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.1.0
[INFO] [stderr]    Compiling libc v0.2.126
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]    Compiling parking_lot_core v0.9.3
[INFO] [stderr]     Checking smallvec v1.8.0
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]     Checking nodrop v0.1.14
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]     Checking constant_time_eq v0.1.5
[INFO] [stderr]     Checking byteorder v1.4.3
[INFO] [stderr]     Checking arrayref v0.3.6
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking array-init v2.0.0
[INFO] [stderr]     Checking dusk-varint v0.1.0
[INFO] [stderr]     Checking arbitrary v1.1.0
[INFO] [stderr]    Compiling lock_api v0.4.7
[INFO] [stderr]     Checking blake2b_simd v0.3.1
[INFO] [stderr]     Checking parking_lot v0.12.0
[INFO] [stderr]  Documenting canonical v0.7.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:16:1
[INFO] [stdout]    |
[INFO] [stdout] 16 | #![feature(never_type)]
[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 `canonical`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name canonical src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=b282063c2ec297ad -L dependency=/opt/rustwide/target/debug/deps --extern arbitrary=/opt/rustwide/target/debug/deps/libarbitrary-dedb26c148782ffd.rmeta --extern array_init=/opt/rustwide/target/debug/deps/libarray_init-289bf2c828644f3a.rmeta --extern blake2b_simd=/opt/rustwide/target/debug/deps/libblake2b_simd-d8ea1de2e6a9c5ab.rmeta --extern cfg_if=/opt/rustwide/target/debug/deps/libcfg_if-dcce77079dd8fe1e.rmeta --extern dusk_varint=/opt/rustwide/target/debug/deps/libdusk_varint-f7d62df9f49e3220.rmeta --extern lazy_static=/opt/rustwide/target/debug/deps/liblazy_static-1479f2b7adeaa2b6.rmeta --extern parking_lot=/opt/rustwide/target/debug/deps/libparking_lot-22c0cb714e7839b6.rmeta --cap-lints=warn --crate-version 0.7.1` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "294428e8df020088e3e4340cb1476aedfa23ce7041d05c342c2c3d792d502ed7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "294428e8df020088e3e4340cb1476aedfa23ce7041d05c342c2c3d792d502ed7", kill_on_drop: false }`
[INFO] [stdout] 294428e8df020088e3e4340cb1476aedfa23ce7041d05c342c2c3d792d502ed7