core-error 0.0.1-rc4

# rustc version
rustc 1.43.0-nightly (7cdbc87a4 2020-03-14)# docs.rs version
docsrs 0.6.0 (3ababaf 2020-03-14)# build log
[INFO] running `"docker" "create" "-v" "/home/cratesfyi/workspace/builds/core-error-0.0.1-rc4/target:/opt/rustwide/target:rw,Z" "-v" "/home/cratesfyi/workspace/builds/core-error-0.0.1-rc4/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 -20200314-1.43.0-nightly-7cdbc87a4 --static-root-path / --extern-html-root-url version_check=https://docs.rs/version_check/0.9.1" "-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"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 074311a5a26d29dbfab0ffe0337ce9e7ea6a3b295a4169a93f4845b47efd7de6
[INFO] running `"docker" "start" "-a" "074311a5a26d29dbfab0ffe0337ce9e7ea6a3b295a4169a93f4845b47efd7de6"`
[INFO] [stderr]    Compiling version_check v0.9.1
[INFO] [stderr]    Compiling core-error v0.0.1-rc4 (/opt/rustwide/workdir)
[INFO] [stderr]  Documenting core-error v0.0.1-rc4 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.65s
[INFO] running `"docker" "inspect" "074311a5a26d29dbfab0ffe0337ce9e7ea6a3b295a4169a93f4845b47efd7de6"`
[INFO] running `"docker" "rm" "-f" "074311a5a26d29dbfab0ffe0337ce9e7ea6a3b295a4169a93f4845b47efd7de6"`
[INFO] [stdout] 074311a5a26d29dbfab0ffe0337ce9e7ea6a3b295a4169a93f4845b47efd7de6