feat: Add support for Haiku OS

Haiku does not support pipe_with at all, so just fall back to pipe().

.github/workflows/ci.yml

@@ -68,6 +68,9 @@ jobs:
       - name: Check selected Tier 3 targets
         if: startsWith(matrix.rust, 'nightly') && matrix.os == 'ubuntu-latest'
         run: cargo check -Z build-std --target=riscv32imc-esp-espidf
+      - name: Check haiku
+        if: startsWith(matrix.rust, 'nightly') && matrix.os == 'ubuntu-latest'
+        run: cargo check -Z build-std --target x86_64-unknown-haiku
 
   cross:
     runs-on: ${{ matrix.os }}

src/poll.rs

@@ -447,7 +447,9 @@ mod notify {
     use rustix::fd::{AsFd, AsRawFd, BorrowedFd, OwnedFd, RawFd};
     use rustix::fs::{fcntl_getfl, fcntl_setfl, OFlags};
     use rustix::io::{fcntl_getfd, fcntl_setfd, read, write, FdFlags};
-    use rustix::pipe::{pipe, pipe_with, PipeFlags};
+    #[cfg(not(target_os = "haiku"))]
+    use rustix::pipe::pipe_with;
+    use rustix::pipe::{pipe, PipeFlags};
 
     /// A notification pipe.
     ///
@@ -468,12 +470,18 @@ mod notify {
     impl Notify {
         /// Creates a new notification pipe.
         pub(super) fn new() -> io::Result<Self> {
-            let (read_pipe, write_pipe) = pipe_with(PipeFlags::CLOEXEC).or_else(|_| {
+            let fallback_pipe = |_| {
                 let (read_pipe, write_pipe) = pipe()?;
                 fcntl_setfd(&read_pipe, fcntl_getfd(&read_pipe)? | FdFlags::CLOEXEC)?;
                 fcntl_setfd(&write_pipe, fcntl_getfd(&write_pipe)? | FdFlags::CLOEXEC)?;
                 io::Result::Ok((read_pipe, write_pipe))
-            })?;
+            };
+
+            #[cfg(not(target_os = "haiku"))]
+            let (read_pipe, write_pipe) = pipe_with(PipeFlags::CLOEXEC).or_else(fallback_pipe)?;
+
+            #[cfg(target_os = "haiku")]
+            let (read_pipe, write_pipe) = fallback_pipe(PipeFlags::CLOEXEC)?;
 
             // Put the reading side into non-blocking mode.
             fcntl_setfl(&read_pipe, fcntl_getfl(&read_pipe)? | OFlags::NONBLOCK)?;