[INFO] fetching crate null-terminated 0.3.14...
[INFO] documenting null-terminated-0.3.14 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate null-terminated 0.3.14 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate null-terminated 0.3.14 on toolchain beta-2020-08-29
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate null-terminated 0.3.14
[INFO] finished tweaking crates.io crate null-terminated 0.3.14
[INFO] tweaked toml for crates.io crate null-terminated 0.3.14 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate crates.io crate null-terminated 0.3.14 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded utf v0.1.5
[INFO] [stderr]   Downloaded unreachable v1.0.0
[INFO] [stderr]   Downloaded quickcheck_macros v0.8.0
[INFO] [stderr]   Downloaded quickcheck v0.8.5
[INFO] [stderr]   Downloaded system-call v0.1.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-08-29" "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] c9ed6737b50f8322f645b578f22ae602778de09f69a7c0e5eebf5391908a8e9d
[INFO] running `Command { std: "docker" "start" "-a" "c9ed6737b50f8322f645b578f22ae602778de09f69a7c0e5eebf5391908a8e9d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c9ed6737b50f8322f645b578f22ae602778de09f69a7c0e5eebf5391908a8e9d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c9ed6737b50f8322f645b578f22ae602778de09f69a7c0e5eebf5391908a8e9d", kill_on_drop: false }`
[INFO] [stdout] c9ed6737b50f8322f645b578f22ae602778de09f69a7c0e5eebf5391908a8e9d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 81c8b7b39df2617f68a279f4d2bed8fabfadb5f7ad25bfc59f99408bd16c502f
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "81c8b7b39df2617f68a279f4d2bed8fabfadb5f7ad25bfc59f99408bd16c502f", kill_on_drop: false }`
[INFO] [stderr]     Checking utf v0.1.5
[INFO] [stderr]     Checking unreachable v1.0.0
[INFO] [stderr]  Documenting null-terminated v0.3.14 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:25:1
[INFO] [stdout]    |
[INFO] [stdout] 25 | #![feature(cfg_doctest)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:26:1
[INFO] [stdout]    |
[INFO] [stdout] 26 | #![feature(const_fn)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:27:1
[INFO] [stdout]    |
[INFO] [stdout] 27 | #![feature(const_raw_ptr_deref)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:28:1
[INFO] [stdout]    |
[INFO] [stdout] 28 | #![feature(extern_types)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 5 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 `null-terminated`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name null_terminated src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --cfg 'feature="utf"' --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern unreachable=/opt/rustwide/target/debug/deps/libunreachable-d6ace0a9f649a31a.rmeta --extern utf=/opt/rustwide/target/debug/deps/libutf-b2369a45e20361cf.rmeta --cap-lints=warn --crate-version 0.3.14` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "81c8b7b39df2617f68a279f4d2bed8fabfadb5f7ad25bfc59f99408bd16c502f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "81c8b7b39df2617f68a279f4d2bed8fabfadb5f7ad25bfc59f99408bd16c502f", kill_on_drop: false }`
[INFO] [stdout] 81c8b7b39df2617f68a279f4d2bed8fabfadb5f7ad25bfc59f99408bd16c502f