hostname 0.3.1

# rustc version
rustc 1.43.0-nightly (6d69caba1 2020-02-27)# docs.rs version
docsrs 0.6.0 (7de24ca 2020-02-23)# build log
[INFO] running `"docker" "create" "-v" "/home/cratesfyi/workspace/builds/hostname-0.3.1/target:/opt/rustwide/target:rw,Z" "-v" "/home/cratesfyi/workspace/builds/hostname-0.3.1/source:/opt/rustwide/workdir:ro,Z" "-v" "/home/cratesfyi/workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/home/cratesfyi/workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1001" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "RUSTFLAGS=" "-e" "RUSTDOCFLAGS=-Z unstable-options --resource-suffix -20200227-1.43.0-nightly-6d69caba1 --static-root-path / --extern-html-root-url libc=https://docs.rs/libc/0.2.66 --extern-html-root-url match_cfg=https://docs.rs/match_cfg/0.1.0 --extern-html-root-url version_sync=https://docs.rs/version-sync/0.8.1 --extern-html-root-url winapi=https://docs.rs/winapi/0.3.8 --cfg docsrs" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "3221225472" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+nightly" "doc" "--lib" "--no-deps" "--features" "set"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] a6a6de41c0c539483435ad4c28777c89a6842ffa743054136634b6dfc4b81751
[INFO] running `"docker" "start" "-a" "a6a6de41c0c539483435ad4c28777c89a6842ffa743054136634b6dfc4b81751"`
[INFO] [stderr]    Compiling libc v0.2.66
[INFO] [stderr]     Checking match_cfg v0.1.0
[INFO] [stderr]  Documenting hostname v0.3.1 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0658]: `#[doc(cfg)]` is experimental
[INFO] [stderr]    --> src/lib.rs:142:20
[INFO] [stderr]     |
[INFO] [stderr] 142 | #[cfg_attr(docsrs, doc(cfg(feature = "set")))]
[INFO] [stderr]     |                    ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: see issue #43781 <https://github.com/rust-lang/rust/issues/43781> for more information
[INFO] [stderr]     = help: add `#![feature(doc_cfg)]` to the crate attributes to enable
[INFO] [stderr] 
[INFO] [stderr] error: Compilation failed, aborting rustdoc
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0658`.
[INFO] [stderr] error: Could not document `hostname`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name hostname src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --cfg 'feature="set"' --error-format=json --json=diagnostic-rendered-ansi -L dependency=/opt/rustwide/target/debug/deps --extern libc=/opt/rustwide/target/debug/deps/liblibc-5de0ecbb0f7d5664.rmeta --extern match_cfg=/opt/rustwide/target/debug/deps/libmatch_cfg-5fd87eb4895c2797.rmeta -Z unstable-options --resource-suffix -20200227-1.43.0-nightly-6d69caba1 --static-root-path / --extern-html-root-url 'libc=https://docs.rs/libc/0.2.66' --extern-html-root-url 'match_cfg=https://docs.rs/match_cfg/0.1.0' --extern-html-root-url 'version_sync=https://docs.rs/version-sync/0.8.1' --extern-html-root-url 'winapi=https://docs.rs/winapi/0.3.8' --cfg docsrs` (exit code: 1)
[INFO] running `"docker" "inspect" "a6a6de41c0c539483435ad4c28777c89a6842ffa743054136634b6dfc4b81751"`
[INFO] running `"docker" "rm" "-f" "a6a6de41c0c539483435ad4c28777c89a6842ffa743054136634b6dfc4b81751"`
[INFO] [stdout] a6a6de41c0c539483435ad4c28777c89a6842ffa743054136634b6dfc4b81751