Remove "runtime" hidden feature of rustix, replace with safe-fork

Cargo.toml

@@ -16,12 +16,13 @@ tokio = { version = "1", features = ["full"] }
 tokio-stream = "0.1"
 async-stream = "0.3"
 udev = "0.8"
-rustix = { version = "0.38", features = ["fs", "stdio", "process", "thread", "runtime", "pipe"] }
+rustix = { version = "0.38", features = ["fs", "stdio", "process", "thread", "pipe"] }
 bitflags = "2"
 once_cell = "1"
 humantime = "2"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
+safe-fork = "0.1.1"
 aya = { git = "https://github.com/aya-rs/aya.git" }
 
 [build-dependencies]

src/main.rs

@@ -23,8 +23,7 @@ use runc::cli::{CreateOptions, GlobalOptions};
 use runc::Container;
 use rustix::fd::OwnedFd;
 use rustix::pipe::PipeFlags;
-use rustix::process::{Signal, WaitOptions};
-use rustix::runtime::Fork;
+use rustix::process::Signal;
 use tokio_stream::StreamExt;
 
 #[derive(Clone)]
@@ -225,21 +224,16 @@ fn do_main() -> Result<()> {
     // or the child process closing it.
     let (parent, child) = rustix::pipe::pipe_with(PipeFlags::CLOEXEC)?;
     // SAFETY: forking is safe because we are single-threaded now.
-    match unsafe { rustix::runtime::fork()? } {
-        Fork::Child(_) => {
+    match safe_fork::fork()? {
+        None => {
             drop(parent);
             tokio::runtime::Runtime::new()?.block_on(create(args.global, create_options, child))?;
         }
-        Fork::Parent(pid) => {
+        Some(pid) => {
             drop(child);
             if rustix::io::read(parent, &mut [0])? == 0 {
                 // In this case, the child process exited before notifying us.
-                std::process::exit(
-                    rustix::process::waitpid(Some(pid), WaitOptions::empty())?
-                        .unwrap()
-                        .exit_status()
-                        .unwrap_or(1) as _,
-                );
+                std::process::exit(pid.join()?.code().unwrap_or(1) as _);
             }
         }
     }