Magical wait to get rid of deadlock on macOS

1 files changed, 4 insertions, 0 deletions

diff --git a/test/ruby/test_process.rb b/test/ruby/test_process.rb
index 5787f2dbe2..f180b6368d 100644
--- a/test/ruby/test_process.rb
+++ b/test/ruby/test_process.rb
@@ -715,6 +715,10 @@ class TestProcess < Test::Unit::TestCase
         sleep 0.2 # wait for the child to stop at opening "fifo"
         Process.kill(:USR1, io.pid)
         assert_equal("trap\n", io.readpartial(8))
+        sleep 0.2 # wait for the child to return to opening "fifo".
+        # On arm64-darwin22, often deadlocks while the child is
+        # opening "fifo".  Not sure to where "ok" line being written
+        # at the next has gone.
         File.write("fifo", "ok\n")
         assert_equal("ok\n", io.read)
       }