Fix for leaking file descriptor issue

runtime/bin/process_macos.cc

Index: runtime/bin/process_macos.cc
diff --git a/runtime/bin/process_macos.cc b/runtime/bin/process_macos.cc
index 0022a8b6cdde8c3c433058226ac12342e3851cdb..43dcc285ecf23488e701b2bf59b7f3a0adf330f3 100644
--- a/runtime/bin/process_macos.cc
+++ b/runtime/bin/process_macos.cc
@@ -532,6 +532,14 @@ int Process::Start(const char* path,
     VOID_TEMP_FAILURE_RETRY(close(read_err[1]));
     VOID_TEMP_FAILURE_RETRY(close(write_out[0]));
     VOID_TEMP_FAILURE_RETRY(close(write_out[1]));
+
+    // Since exec() failed, we're not interested in the exit code.
+    // We close the reading side of the exit code pipe here.
+    // GetProcessExitCodes will get a broken pipe error when it tries to write
+    // to the writing side of the pipe and it will ignore the error.
+    VOID_TEMP_FAILURE_RETRY(close(*exit_event));
+    *exit_event = -1;
+
     if (bytes_read == -1) {
       return errno;  // Read failed.
     } else {