[INFO] fetching crate ct-utils 0.0.1...
[INFO] documenting ct-utils-0.0.1 against beta-2022-05-20 for beta-1.62-rustdoc-1
[INFO] extracting crate ct-utils 0.0.1 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate ct-utils 0.0.1 on toolchain beta-2022-05-20
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2022-05-20" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate ct-utils 0.0.1
[INFO] finished tweaking crates.io crate ct-utils 0.0.1
[INFO] tweaked toml for crates.io crate ct-utils 0.0.1 written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2022-05-20" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2022-05-20" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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" "+beta-2022-05-20" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 6dd92165da0b3d2a549b1bbc56e2fa43f1d62e6c8bb50967a3aef4bd428be684
[INFO] running `Command { std: "docker" "start" "-a" "6dd92165da0b3d2a549b1bbc56e2fa43f1d62e6c8bb50967a3aef4bd428be684", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6dd92165da0b3d2a549b1bbc56e2fa43f1d62e6c8bb50967a3aef4bd428be684", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6dd92165da0b3d2a549b1bbc56e2fa43f1d62e6c8bb50967a3aef4bd428be684", kill_on_drop: false }`
[INFO] [stdout] 6dd92165da0b3d2a549b1bbc56e2fa43f1d62e6c8bb50967a3aef4bd428be684
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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" "+beta-2022-05-20" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 8df207d3f84d9a50d105e1ff7177ee2f1c3db65a238c5039d359bf19ce13132f
[INFO] running `Command { std: "docker" "start" "-a" "8df207d3f84d9a50d105e1ff7177ee2f1c3db65a238c5039d359bf19ce13132f", kill_on_drop: false }`
[INFO] [stderr]  Documenting ct-utils v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(specialization)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(specialization)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]   = help: consider using `min_specialization` instead, which is more stable and complete
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `ct-utils`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name ct_utils src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=ce9b85751902864a -L dependency=/opt/rustwide/target/debug/deps --extern typenum=/opt/rustwide/target/debug/deps/libtypenum-ce4092128de0337b.rmeta --cap-lints=warn --crate-version 0.0.1` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "8df207d3f84d9a50d105e1ff7177ee2f1c3db65a238c5039d359bf19ce13132f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8df207d3f84d9a50d105e1ff7177ee2f1c3db65a238c5039d359bf19ce13132f", kill_on_drop: false }`
[INFO] [stdout] 8df207d3f84d9a50d105e1ff7177ee2f1c3db65a238c5039d359bf19ce13132f