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If you have already built various versions and you don't want to recreate them, then don't do the delete step in the earlier example. Retain the website. Each version is in the website's /version folder. Also, each version that was built and pre-update is in the docs/build_version_doc/<fork-username> folder. You can also run the one-off site build using make html. Copy your newly created versions of the site into aptly named subfolders within the the docs/build_version_doc/<fork-username> folder. Then rerun update_all_version.sh with the versions you want to appear in the dropdown list. Take that output and serve it, or even make a new directory in /var/www/html/versions and copy it in there, so you can run many flavors of the site at will.