[INFO] fetching crate eng-wasm 0.1.7...
[INFO] documenting eng-wasm-0.1.7 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate eng-wasm 0.1.7 into /workspace/builds/worker-63/source
[INFO] validating manifest of crates.io crate eng-wasm 0.1.7 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 eng-wasm 0.1.7
[INFO] finished tweaking crates.io crate eng-wasm 0.1.7
[INFO] tweaked toml for crates.io crate eng-wasm 0.1.7 written to /workspace/builds/worker-63/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]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-63/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-63/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] 025f936b98c2cb13e71ed8c1a8ca47630d4b4c99a5791da8c0a0600f3d9c7483
[INFO] running `Command { std: "docker" "start" "-a" "025f936b98c2cb13e71ed8c1a8ca47630d4b4c99a5791da8c0a0600f3d9c7483", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "025f936b98c2cb13e71ed8c1a8ca47630d4b4c99a5791da8c0a0600f3d9c7483", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "025f936b98c2cb13e71ed8c1a8ca47630d4b4c99a5791da8c0a0600f3d9c7483", kill_on_drop: false }`
[INFO] [stdout] 025f936b98c2cb13e71ed8c1a8ca47630d4b4c99a5791da8c0a0600f3d9c7483
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-63/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-63/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] dbaee0b1ff2bf46038c8a11e795dbbac35968b16209043b387142035dce8fc81
[INFO] running `Command { std: "docker" "start" "-a" "dbaee0b1ff2bf46038c8a11e795dbbac35968b16209043b387142035dce8fc81", kill_on_drop: false }`
[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 serde_derive v1.0.137
[INFO] [stderr]    Compiling serde v1.0.137
[INFO] [stderr]    Compiling crunchy v0.2.2
[INFO] [stderr]     Checking rustc-hex v2.1.0
[INFO] [stderr]    Compiling serde_json v1.0.81
[INFO] [stderr]     Checking static_assertions v0.2.5
[INFO] [stderr]     Checking byteorder v1.4.3
[INFO] [stderr]     Checking itoa v1.0.2
[INFO] [stderr]     Checking ryu v1.0.10
[INFO] [stderr]     Checking fixed-hash v0.3.2
[INFO] [stderr]     Checking uint v0.6.1
[INFO] [stderr]    Compiling quote v1.0.18
[INFO] [stderr]     Checking eng-pwasm-abi v0.3.2
[INFO] [stderr]  Documenting eng-wasm v0.1.7 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(slice_concat_trait)]
[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 `eng-wasm`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name eng_wasm src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=a2db95ff372c628f -L dependency=/opt/rustwide/target/debug/deps --extern eng_pwasm_abi=/opt/rustwide/target/debug/deps/libeng_pwasm_abi-1ad98d25e88707b9.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-100e02e707928638.rmeta --extern serde_json=/opt/rustwide/target/debug/deps/libserde_json-d98489a7573185e5.rmeta --cap-lints=warn --crate-version 0.1.7` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "dbaee0b1ff2bf46038c8a11e795dbbac35968b16209043b387142035dce8fc81", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dbaee0b1ff2bf46038c8a11e795dbbac35968b16209043b387142035dce8fc81", kill_on_drop: false }`
[INFO] [stdout] dbaee0b1ff2bf46038c8a11e795dbbac35968b16209043b387142035dce8fc81