FileUtils#ln_sr

# File tmp/rubies/ruby-4.0.0/lib/fileutils.rb, line 733
def ln_sr(src, dest, target_directory: true, force: nil, noop: nil, verbose: nil)
  cmd = "ln -s#{force ? 'f' : ''}#{target_directory ? '' : 'T'}" if verbose
  fu_each_src_dest0(src, dest, target_directory) do |s,d|
    if target_directory
      parent = File.dirname(d)
      destdirs = fu_split_path(parent)
      real_ddirs = fu_split_path(File.realpath(parent))
    else
      destdirs ||= fu_split_path(dest)
      real_ddirs ||= fu_split_path(File.realdirpath(dest))
    end
    srcdirs = fu_split_path(s)
    i = fu_common_components(srcdirs, destdirs)
    n = destdirs.size - i
    n -= 1 unless target_directory
    link1 = fu_clean_components(*Array.new([n, 0].max, '..'), *srcdirs[i..-1])
    begin
      real_sdirs = fu_split_path(File.realdirpath(s)) rescue nil
    rescue
    else
      i = fu_common_components(real_sdirs, real_ddirs)
      n = real_ddirs.size - i
      n -= 1 unless target_directory
      link2 = fu_clean_components(*Array.new([n, 0].max, '..'), *real_sdirs[i..-1])
      link1 = link2 if link1.size > link2.size
    end
    s = File.join(link1)
    fu_output_message [cmd, s, d].flatten.join(' ') if verbose
    next if noop
    remove_file d, true if force
    File.symlink s, d
  end
end