I don't understand the advantage of this library over bare `libsystemd-sys`

[m-kuzmin]

I started with trying to add support for connecting to containers, but I've found way too many issues just in this code I was going to put into an /examples/ file:

#![warn(rust_2018_idioms)]

use clap::Parser;
use utf8_cstr::Utf8CStr;

#[derive(Parser)]
struct Args {
    #[args(short = 'M', long)]
    machine: String,

    service: String,
}

#[cfg(feature = "bus")]
fn main() -> anyhow::Result<()> {
    let Args { machine, service } = Args::parse();

    // the function I was going to add
    let mut bus = systemd::bus::Bus::open_system_machine(&machine)?;

    let mut method_call = bus.new_method_call(
        // ⚠️ Null-terminated strings? I don't want to deal with that, all my code uses &str.
        // ⚠️ `?` couldn't convert the error: `str: std::error::Error` is not satisfied
        //    omg! the errors are strings...
        systemd::bus::BusName::from_bytes(b"org.freedesktop.systemd1\0")?,
        systemd::bus::ObjectPath::from_bytes(b"/org/freedesktop/systemd1\0")?,
        systemd::bus::InterfaceName::from_bytes(b"org.freedesktop.systemd1.Manager\0")?,
        systemd::bus::MemberName::from_bytes(b"StartUnit\0")?,
    )?;

    // args
    method_call.append(Utf8CStr::from_bytes(b"foo.service\0")?)?;
    method_call.append(Utf8CStr::from_bytes(b"fail\0")?)?;

    let res = method_call.call(0)?;

    eprintln!("done, result={:?}", *res);

    Ok(())
}

#[cfg(not(feature = "bus"))]
fn main() {
    println!("bus disabled");
}

I genuinely don't understand what the point of this crate is because it solves the unsafe problem, but then it doesn't go all the way! This is what I was expecting:

let bus = Bus::open_system_machine(&machine)?;
bus.start_unit(&unit)?;

Okay, maybe not that simplified, but this is just really not acceptable. I'm basically 50/50 deciding if I just learn unsafe Rust, or rewrite all the pain points of this crate in a fork.

I'm not sure what kind of response I'm expecting because on the one hand, I need a library that fits my needs, but on the other hand I may not understand the point of this crate.