class RSpec::Support::StdErrSplitter

def write(line)

TypeError: $stderr must have write method, RSpec::StdErrSplitter given
To work around JRuby error: 
def write(line)
  return if line =~ %r{^\S+/gems/\S+:\d+: warning:} # http://rubular.com/r/kqeUIZOfPG
  # Ruby 2.7.0 warnings from keyword arguments span multiple lines, extend check above
  # to look for the next line.
  return if @last_line =~ %r{^\S+/gems/\S+:\d+: warning:} &&
            line =~ %r{warning: The called method .* is defined here}
  # Ruby 2.7.0 complains about hashes used in place of keyword arguments
  # Aruba 0.14.2 uses this internally triggering that here
  return if line =~ %r{lib/ruby/2\.7\.0/fileutils\.rb:622: warning:}
  @orig_stderr.write(line)
  @output_tracker.write(line)
ensure
  @last_line = line
end