oping 0.4.0

# rustc version
rustc 1.46.0-nightly (449e8eaa2 2020-06-10)
# docs.rs version
docsrs 0.6.0 (5b2fdf4 2020-06-19)

# build log
[INFO] running `Command { std: "docker" "create" "-v" "/home/cratesfyi/workspace/builds/oping-0.4.0/target:/opt/rustwide/target:rw,Z" "-v" "/home/cratesfyi/workspace/builds/oping-0.4.0/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 -20200610-1.46.0-nightly-449e8eaa2 --static-root-path / --cap-lints warn --extern-html-root-url libc=https://docs.rs/libc/0.2.71 --extern-html-root-url cc=https://docs.rs/cc/1.0.54 --extern-html-root-url pkg_config=https://docs.rs/pkg-config/0.3.17" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "3221225472" "--cpus" "2" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+nightly-2020-06-11" "doc" "--lib" "--no-deps" "-j2", kill_on_drop: false }`
[INFO] [stdout] d79096c36eabdc37b4b790d64274826d8e94ddbfc56f0ce83a1ac122a69b1a6c
[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" "d79096c36eabdc37b4b790d64274826d8e94ddbfc56f0ce83a1ac122a69b1a6c", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.71
[INFO] [stderr]    Compiling cc v1.0.54
[INFO] [stderr]    Compiling pkg-config v0.3.17
[INFO] [stderr]    Compiling oping v0.4.0 (/opt/rustwide/workdir)
[INFO] [stderr] error: failed to run custom build command for `oping v0.4.0 (/opt/rustwide/workdir)`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/target/debug/build/oping-9aed8cfc4ff65e16/build-script-build` (exit code: 101)
[INFO] [stderr] --- stderr
[INFO] [stderr] Could not find liboping on your system! This Rust crate
[INFO] [stderr] requires the C library liboping to be installed (it is
[INFO] [stderr] simply a wrapper around this library). Please install
[INFO] [stderr] liboping from https://noping.cc/ or your system's package
[INFO] [stderr] manager, and ensure that `pkg-config` can provide its build
[INFO] [stderr] flags. If build issues persist, please do not open an issue
[INFO] [stderr] without first ensuring that `pkg-config --libs liboping`
[INFO] [stderr] returns something reasonable.
[INFO] [stderr] thread 'main' panicked at 'Could not find liboping via pkg-config: Failure { command: "\"pkg-config\" \"--libs\" \"--cflags\" \"liboping\" \"liboping >= 1.10.0\"", output: Output { status: ExitStatus(ExitStatus(256)), stdout: "", stderr: "Package liboping was not found in the pkg-config search path.\nPerhaps you should add the directory containing `liboping.pc\'\nto the PKG_CONFIG_PATH environment variable\nNo package \'liboping\' found\nPackage liboping was not found in the pkg-config search path.\nPerhaps you should add the directory containing `liboping.pc\'\nto the PKG_CONFIG_PATH environment variable\nNo package \'liboping\' found\n" } }
[INFO] [stderr] PKG_CONFIG_SYSROOT_DIR=', build.rs:26:9
[INFO] [stderr] note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
[INFO] [stderr] 
[INFO] running `Command { std: "docker" "inspect" "d79096c36eabdc37b4b790d64274826d8e94ddbfc56f0ce83a1ac122a69b1a6c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d79096c36eabdc37b4b790d64274826d8e94ddbfc56f0ce83a1ac122a69b1a6c", kill_on_drop: false }`
[INFO] [stdout] d79096c36eabdc37b4b790d64274826d8e94ddbfc56f0ce83a1ac122a69b1a6c