Gem::BasicSpecification#lib_dirs

# File tmp/rubies/ruby-4.1.0-preview1/lib/rubygems/basic_specification.rb, line 360
def lib_dirs
  if raw_require_paths
    if raw_require_paths.size > 1
      "{#{raw_require_paths.join(",")}}"
    else
      raw_require_paths.first
    end
  else
    "lib" # default value for require_paths for bundler/inline
  end
end