I am facing a convoluted issue with respect to deploying AMP and HTML pages for multiple languages.
The thing is I got both AMP and HTML pages working by adding render-image.amp.html along with render-image.html under _default > _markup and changing <img> to <amp-img> in render-image.amp.html which works great.
Now for the multilingual part:
What Iβm doing is using my index.html and single.html to fix my layouts and then using i18n to change languages wherever necessary as opposed to creating separate index.fr.html and single.fr.html.
It works great when I just have one language. Both AMP and HTML versions render as necessary.
However when I introduce another language eg fr, the default (en)index and single pages (both AMP and HTML) render properly, but for the fr version, only the render-image.html is read.
I tried creating render-image.fr.amp.html and render-image.fr.html, but it seems that these are not used at all for creating the AMP and the HTML pages respectively.
I was able to reproduce the problem with version v0.80. It was fixed a couple of weeks ago. You can either wait until v.082 is released, or build Hugo from source.
I wasnβt able to reproduce the problem earlier today because I built from source after this fix was committed. I apologize for the confusion.