Octopressで最後に編集した記事だけをgenerate ref: http://qiita.com/gam0022/items/7b5a6e4492c90583706f

Rakefile

# usage rake generate_only[my-post]
# thanks to http://rcmdnk.github.io/blog/2013/12/06/blog-octopress-rake/
desc "Generate only the specified post (much faster)"
task :generate_only, :filename do |t, args|
  if args.filename
    filename = args.filename
  else
    filename = Dir.glob("#{source_dir}/#{posts_dir}/*.#{new_post_ext}").sort_by{|f| File.mtime(f)}.last
  end
  puts "## Test build for #{filename}"
  puts "## Stashing other posts"
  Rake::Task[:isolate].invoke(filename)
  Rake::Task[:generate].execute
  puts "## Restoring stashed posts"
  Rake::Task[:integrate].execute
end
task go: :generate_only