[INFO] fetching crate sp-ipld 0.2.0...
[INFO] documenting sp-ipld-0.2.0 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate sp-ipld 0.2.0 into /workspace/builds/worker-36/source
[INFO] validating manifest of crates.io crate sp-ipld 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 sp-ipld 0.2.0
[INFO] finished tweaking crates.io crate sp-ipld 0.2.0
[INFO] tweaked toml for crates.io crate sp-ipld 0.2.0 written to /workspace/builds/worker-36/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]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded sp-multihash v0.2.0
[INFO] [stderr]   Downloaded sp-cid v0.2.0
[INFO] [stderr]   Downloaded bytecursor v0.1.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-36/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-36/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] 2fe3bef6fa41aebc06cc3dd01aa2998be6c98be3f7304f6c313d02acb4bebc5f
[INFO] running `Command { std: "docker" "start" "-a" "2fe3bef6fa41aebc06cc3dd01aa2998be6c98be3f7304f6c313d02acb4bebc5f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2fe3bef6fa41aebc06cc3dd01aa2998be6c98be3f7304f6c313d02acb4bebc5f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2fe3bef6fa41aebc06cc3dd01aa2998be6c98be3f7304f6c313d02acb4bebc5f", kill_on_drop: false }`
[INFO] [stdout] 2fe3bef6fa41aebc06cc3dd01aa2998be6c98be3f7304f6c313d02acb4bebc5f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-36/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-36/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] b2872176df94ea925145639e054a2022e1803809c3dfdd6ba467002f77a829ed
[INFO] running `Command { std: "docker" "start" "-a" "b2872176df94ea925145639e054a2022e1803809c3dfdd6ba467002f77a829ed", kill_on_drop: false }`
[INFO] [stderr]    Compiling version_check v0.9.4
[INFO] [stderr]    Compiling proc-macro2 v1.0.39
[INFO] [stderr]    Compiling unicode-ident v1.0.0
[INFO] [stderr]    Compiling syn v1.0.95
[INFO] [stderr]    Compiling typenum v1.15.0
[INFO] [stderr]    Compiling serde v1.0.137
[INFO] [stderr]    Compiling cc v1.0.73
[INFO] [stderr]     Checking arrayvec v0.5.2
[INFO] [stderr]     Checking constant_time_eq v0.1.5
[INFO] [stderr]     Checking block-padding v0.2.1
[INFO] [stderr]     Checking arrayref v0.3.6
[INFO] [stderr]     Checking subtle v2.4.1
[INFO] [stderr]    Compiling unicode-xid v0.2.3
[INFO] [stderr]    Compiling data-encoding v2.3.2
[INFO] [stderr]     Checking opaque-debug v0.3.0
[INFO] [stderr]     Checking keccak v0.1.2
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking cpufeatures v0.2.2
[INFO] [stderr]     Checking sp-std v3.0.0
[INFO] [stderr]     Checking unsigned-varint v0.7.1
[INFO] [stderr]    Compiling serde_json v1.0.81
[INFO] [stderr]     Checking base-x v0.2.10
[INFO] [stderr]     Checking ryu v1.0.10
[INFO] [stderr]     Checking itoa v1.0.2
[INFO] [stderr]     Checking base64 v0.13.0
[INFO] [stderr]     Checking byteorder v1.4.3
[INFO] [stderr]     Checking bytecursor v0.1.2
[INFO] [stderr]    Compiling generic-array v0.14.5
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]     Checking blake2b_simd v0.5.11
[INFO] [stderr]     Checking blake2s_simd v0.5.11
[INFO] [stderr]    Compiling quote v1.0.18
[INFO] [stderr]    Compiling blake3 v0.3.8
[INFO] [stderr]     Checking digest v0.9.0
[INFO] [stderr]     Checking block-buffer v0.9.0
[INFO] [stderr]     Checking crypto-mac v0.8.0
[INFO] [stderr]     Checking sha3 v0.9.1
[INFO] [stderr]     Checking sha2 v0.9.9
[INFO] [stderr]    Compiling toml v0.5.9
[INFO] [stderr]    Compiling synstructure v0.12.6
[INFO] [stderr]    Compiling thiserror-impl v1.0.31
[INFO] [stderr]    Compiling data-encoding-macro-internal v0.1.10
[INFO] [stderr]     Checking data-encoding-macro v0.1.12
[INFO] [stderr]     Checking multibase v0.9.1
[INFO] [stderr]    Compiling thiserror v1.0.31
[INFO] [stderr]    Compiling proc-macro-crate v1.1.3
[INFO] [stderr]    Compiling sp-multihash-derive v0.2.0
[INFO] [stderr]     Checking sp-multihash v0.2.0
[INFO] [stderr]     Checking sp-cid v0.2.0
[INFO] [stderr]  Documenting sp-ipld 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:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(map_first_last)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `sp-ipld`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name sp_ipld src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="base64"' --cfg 'feature="byteorder"' --cfg 'feature="dag-cbor"' --cfg 'feature="dag-json"' --cfg 'feature="default"' --cfg 'feature="multibase"' --cfg 'feature="serde"' --cfg 'feature="sp-multihash"' --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=072fb859f8d14f55 -L dependency=/opt/rustwide/target/debug/deps --extern base64=/opt/rustwide/target/debug/deps/libbase64-8bcb81a96746c276.rmeta --extern bytecursor=/opt/rustwide/target/debug/deps/libbytecursor-0bd88f4e2c492303.rmeta --extern byteorder=/opt/rustwide/target/debug/deps/libbyteorder-abfed71c265ad58b.rmeta --extern multibase=/opt/rustwide/target/debug/deps/libmultibase-da4ca8b5174af8e2.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-20578e47c3244b08.rmeta --extern serde_json=/opt/rustwide/target/debug/deps/libserde_json-23b57d0e398ee659.rmeta --extern sp_cid=/opt/rustwide/target/debug/deps/libsp_cid-59ecaef9f9115e47.rmeta --extern sp_multihash=/opt/rustwide/target/debug/deps/libsp_multihash-6a03600f92fb6026.rmeta --extern unsigned_varint=/opt/rustwide/target/debug/deps/libunsigned_varint-c944d9574b842f2c.rmeta --cap-lints=warn --crate-version 0.2.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "b2872176df94ea925145639e054a2022e1803809c3dfdd6ba467002f77a829ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b2872176df94ea925145639e054a2022e1803809c3dfdd6ba467002f77a829ed", kill_on_drop: false }`
[INFO] [stdout] b2872176df94ea925145639e054a2022e1803809c3dfdd6ba467002f77a829ed