From 76b27ae298e991373116596f2efb68a61919c7fd Mon Sep 17 00:00:00 2001
From: Steve Lau <stevelauc@outlook.com>
Date: Sun, 2 Feb 2025 20:14:39 +0800
Subject: [PATCH 1/2] fix: posix_spawn returns errno when on error, not -1

---
 src/spawn.rs | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/spawn.rs b/src/spawn.rs
index eeb9b7871d..bd8858a922 100644
--- a/src/spawn.rs
+++ b/src/spawn.rs
@@ -370,7 +370,7 @@ pub fn posix_spawn<SA: AsRef<CStr>, SE: AsRef<CStr>>(
 ) -> Result<Pid> {
     let mut pid = 0;
 
-    let res = unsafe {
+    let ret = unsafe {
         let args_p = to_exec_array(args);
         let env_p = to_exec_array(envp);
 
@@ -384,7 +384,10 @@ pub fn posix_spawn<SA: AsRef<CStr>, SE: AsRef<CStr>>(
         )
     };
 
-    Errno::result(res)?;
+    if ret != 0 {
+        return Err(Errno::from_raw(ret));
+    }
+
     Ok(Pid::from_raw(pid))
 }
 
@@ -399,7 +402,7 @@ pub fn posix_spawnp<SA: AsRef<CStr>, SE: AsRef<CStr>>(
 ) -> Result<Pid> {
     let mut pid = 0;
 
-    let res = unsafe {
+    let ret = unsafe {
         let args_p = to_exec_array(args);
         let env_p = to_exec_array(envp);
 
@@ -413,6 +416,9 @@ pub fn posix_spawnp<SA: AsRef<CStr>, SE: AsRef<CStr>>(
         )
     };
 
-    Errno::result(res)?;
+    if ret != 0 {
+        return Err(Errno::from_raw(ret));
+    }
+
     Ok(Pid::from_raw(pid))
 }

From 295dfef7705a63290e68d5a70dabb696993215fc Mon Sep 17 00:00:00 2001
From: Steve Lau <stevelauc@outlook.com>
Date: Sun, 2 Feb 2025 20:24:53 +0800
Subject: [PATCH 2/2] test: acquire the FORK_MTX lock in posix_spawn tests

---
 test/test_spawn.rs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/test/test_spawn.rs b/test/test_spawn.rs
index 1283c96ca8..58dfec31e6 100644
--- a/test/test_spawn.rs
+++ b/test/test_spawn.rs
@@ -1,11 +1,13 @@
-use std::ffi::CString;
-
+use super::FORK_MTX;
 use nix::spawn::{self, PosixSpawnAttr, PosixSpawnFileActions};
 use nix::sys::signal;
 use nix::sys::wait::{waitpid, WaitPidFlag, WaitStatus};
+use std::ffi::CString;
 
 #[test]
 fn spawn_true() {
+    let _guard = FORK_MTX.lock();
+
     let bin = &CString::new("true").unwrap();
     let args = &[
         CString::new("true").unwrap(),
@@ -32,6 +34,8 @@ fn spawn_true() {
 
 #[test]
 fn spawn_sleep() {
+    let _guard = FORK_MTX.lock();
+
     let bin = &CString::new("sleep").unwrap();
     let args = &[CString::new("sleep").unwrap(), CString::new("30").unwrap()];
     let vars: &[CString] = &[];