End of Life Ruby 3.0 has reached end of life and gets no more fixes. Switch to Ruby 4.0 →

instance method

OptionParser#separator

separator(string)

# File tmp/rubies/ruby-3.0.5/lib/optparse.rb, line 1571
def separator(string)
  top.append(string, nil, nil)
end

Add separator in summary.

See also #search #summarize #remove #terminate also in 4.1 · 4.0 · 3.4 · 3.3 · 3.2 · 3.1