I18n inside of printf returns empty string

Is this a bug or a feature I mis-understand?

(printf $messageslug "opensearch" (i18n "dnb-opensearch-error-url") $config.hookLink)

Leads to no error, but the i18n part creates an empty string. Having the translated string instead directly in the call will result in it of course turning up in the printf-output.

Does i18n return something special and not a string? ($messageslug is "%s: %s (%s)")

Unable to reproduce.

git clone --single-branch -b hugo-forum-topic-33589 https://github.com/jmooring/hugo-testing hugo-forum-topic-33589
cd hugo-forum-topic-33589
hugo server

It turns out I didn’t mount the i18n folder of a module that had the translation :face_with_head_bandage: and the CLI was telling me so the whole time.