test to find the IOError

test/cases/helper_cockroachdb.rb

@@ -6,6 +6,30 @@
 # Turn on debugging for the test environment
 ENV['DEBUG_COCKROACHDB_ADAPTER'] = "1"
 
+
+# DEBUG: start debugging the closed for writing message.
+def bugmsg(header, stdout)
+  bugged = ""
+  begin
+    print
+    true
+  rescue IOError
+    bugged = "💥 "
+    false
+  end
+  STDOUT.puts "🤞#{header.rjust(17)}: stdout=#{stdout.inspect} #{bugged}(at #{caller_locations(2, 1).first})"
+end
+
+trace_var :$stdout, (proc { bugmsg("$stdout=", _1) })
+
+TracePoint.trace(:a_return) do |tp|
+  next unless tp.method_id == :reopen
+  next unless tp.self == $stdout
+
+  bugmsg("$stdout#reopen",$stdout)
+end
+# DEBUG: end debugging the closed for writing message.
+
 # Load ActiveRecord test helper
 require "cases/helper"
 

test/cases/migration/foreign_key_test.rb

@@ -295,10 +295,12 @@ def test_add_foreign_key_with_prefix
         def test_add_foreign_key_with_suffix
           ActiveRecord::Base.table_name_suffix = "_s"
           migration = CreateSchoolsAndClassesMigration.new
+          Debug.say "since we are silencing we don't see the error, but somehow the suffix is not coming back"
           silence_stream($stdout) { migration.migrate(:up) }
           assert_equal 1, @connection.foreign_keys("classes_s").size
         ensure
           silence_stream($stdout) { migration.migrate(:down) }
+          Debug.say "does the code goes up till here?"
           ActiveRecord::Base.table_name_suffix = nil
         end