[INFO] fetching crate diff_fmt 0.1.0...
[INFO] documenting diff_fmt-0.1.0 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate diff_fmt 0.1.0 into /workspace/builds/worker-54/source
[INFO] validating manifest of crates.io crate diff_fmt 0.1.0 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] removed /workspace/builds/worker-54/source/rust-toolchain
[INFO] started tweaking crates.io crate diff_fmt 0.1.0
[INFO] finished tweaking crates.io crate diff_fmt 0.1.0
[INFO] tweaked toml for crates.io crate diff_fmt 0.1.0 written to /workspace/builds/worker-54/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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/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] 51a56b218cc77e466d611b6463153f266af10e899c68a857679870ed42779100
[INFO] running `Command { std: "docker" "start" "-a" "51a56b218cc77e466d611b6463153f266af10e899c68a857679870ed42779100", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "51a56b218cc77e466d611b6463153f266af10e899c68a857679870ed42779100", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "51a56b218cc77e466d611b6463153f266af10e899c68a857679870ed42779100", kill_on_drop: false }`
[INFO] [stdout] 51a56b218cc77e466d611b6463153f266af10e899c68a857679870ed42779100
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/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] 7cfdab0f7d716f40f74acfb5906a38fa454362b56d4e61cf668c9b2a1760d9a0
[INFO] running `Command { std: "docker" "start" "-a" "7cfdab0f7d716f40f74acfb5906a38fa454362b56d4e61cf668c9b2a1760d9a0", kill_on_drop: false }`
[INFO] [stderr]     Checking numtoa v0.1.0
[INFO] [stderr]     Checking termion v1.5.6
[INFO] [stderr]  Documenting diff_fmt v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:17:1
[INFO] [stdout]    |
[INFO] [stdout] 17 | #![feature(prelude_import)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:18:1
[INFO] [stdout]    |
[INFO] [stdout] 18 | #![feature(print_internals)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:19:1
[INFO] [stdout]    |
[INFO] [stdout] 19 | #![feature(fmt_internals)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 4 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not document `diff_fmt`
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name diff_fmt src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=21595935e5fca1de -L dependency=/opt/rustwide/target/debug/deps --extern termion=/opt/rustwide/target/debug/deps/libtermion-ccf6d9e10480801d.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "7cfdab0f7d716f40f74acfb5906a38fa454362b56d4e61cf668c9b2a1760d9a0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7cfdab0f7d716f40f74acfb5906a38fa454362b56d4e61cf668c9b2a1760d9a0", kill_on_drop: false }`
[INFO] [stdout] 7cfdab0f7d716f40f74acfb5906a38fa454362b56d4e61cf668c9b2a1760d9a0