Problem: “hugo server” has error “Error: from config: failed to resolve output format "headers" from site config”

Solution:

sudo rm -rf $TMPDIR/hugo_cache/

https://wowchemy.com/docs/hugo-tutorials/troubleshooting/#error-failed-to-resolve-output-format

https://mickaellalande.github.io/post/tutorial/how-to-create-an-academic-github-page-with-hugo/