macos: avoid posix_spawnp() cwd bug (libuv#3597)

macOS 10.15 has a bug where configuring the working directory with
posix_spawn_file_actions_addchdir_np() makes posix_spawnp() fail with
ENOENT even though the executable is spawned successfully.

Co-authored-by: Ben Noordhuis <[email protected]>

src/unix/process.c

@@ -671,27 +671,25 @@ static int uv__spawn_resolve_and_spawn(const uv_process_options_t* options,
  if (options->env != NULL)
  env = options->env;
 
- /* If options->file contains a slash, posix_spawn/posix_spawnp behave
- * the same, and don't involve PATH resolution at all. Otherwise, if
- * options->file does not include a slash, but no custom environment is
- * to be used, the environment used for path resolution as well for the
- * child process is that of the parent process, so posix_spawnp is the
- * way to go. */
- if (strchr(options->file, '/') != NULL || options->env == NULL) {
+ /* If options->file contains a slash, posix_spawn/posix_spawnp should behave
+ * the same, and do not involve PATH resolution at all. The libc
+ * `posix_spawnp` provided by Apple is buggy (since 10.15), so we now emulate it
+ * here, per https://github.com/libuv/libuv/pull/3583. */
+ if (strchr(options->file, '/') != NULL) {
  do
- err = posix_spawnp(pid, options->file, actions, attrs, options->args, env);
+ err = posix_spawn(pid, options->file, actions, attrs, options->args, env);
  while (err == EINTR);
  return err;
  }
 
  /* Look for the definition of PATH in the provided env */
- path = uv__spawn_find_path_in_env(options->env);
+ path = uv__spawn_find_path_in_env(env);
 
  /* The following resolution logic (execvpe emulation) is copied from
  * https://git.musl-libc.org/cgit/musl/tree/src/process/execvp.c
  * and adapted to work for our specific usage */
 
- /* If no path was provided in options->env, use the default value
+ /* If no path was provided in env, use the default value
  * to look for the executable */
  if (path == NULL)
  path = _PATH_DEFPATH;

test/test-list.h

@@ -321,6 +321,7 @@ TEST_DECLARE (spawn_inherit_streams)
 TEST_DECLARE (spawn_quoted_path)
 TEST_DECLARE (spawn_tcp_server)
 TEST_DECLARE (spawn_exercise_sigchld_issue)
+TEST_DECLARE (spawn_relative_path)
 TEST_DECLARE (fs_poll)
 TEST_DECLARE (fs_poll_getpath)
 TEST_DECLARE (fs_poll_close_request)
@@ -956,6 +957,7 @@ TASK_LIST_START
  TEST_ENTRY (spawn_quoted_path)
  TEST_ENTRY (spawn_tcp_server)
  TEST_ENTRY (spawn_exercise_sigchld_issue)
+ TEST_ENTRY (spawn_relative_path)
  TEST_ENTRY (fs_poll)
  TEST_ENTRY (fs_poll_getpath)
  TEST_ENTRY (fs_poll_close_request)

test/test-spawn.c

@@ -1981,3 +1981,37 @@ void spawn_stdin_stdout(void) {
  }
 }
 #endif /* !_WIN32 */
+
+TEST_IMPL(spawn_relative_path) {
+ char* sep;
+
+ init_process_options("spawn_helper1", exit_cb);
+
+ exepath_size = sizeof(exepath) - 2;
+ ASSERT_EQ(0, uv_exepath(exepath, &exepath_size));
+ exepath[exepath_size] = '\0';
+
+ /* Poor man's basename(3). */
+ sep = strrchr(exepath, '/');
+ if (sep == NULL)
+ sep = strrchr(exepath, '\\');
+ ASSERT_NOT_NULL(sep);
+
+ /* Split into dirname and basename and make basename relative. */
+ memmove(sep + 2, sep, 1 + strlen(sep));
+ sep[0] = '\0';
+ sep[1] = '.';
+ sep[2] = '/';
+
+ options.cwd = exepath;
+ options.file = options.args[0] = sep + 1;
+
+ ASSERT_EQ(0, uv_spawn(uv_default_loop(), &process, &options));
+ ASSERT_EQ(0, uv_run(uv_default_loop(), UV_RUN_DEFAULT));
+
+ ASSERT_EQ(1, exit_cb_called);
+ ASSERT_EQ(1, close_cb_called);
+
+ MAKE_VALGRIND_HAPPY();
+ return 0;
+}