Recently CPython's conf.py replaced self-closing tags with simpler, HTML5 ones. It broke EPUB builds as those are not XHTML-compatible.

Could sphinxext-opengraph rewrite custom meta tags to self-closing for EPUB builder?

Alternatives: (1) could sphinxext-opengraph disable custom meta tags for EPUB builder (or allow it through config)? Or: (2) could sphinxext-opengraph disable adding all tags to the layout for EPUB builder (or allow disabling it for EPUB builder through config)?