In addition to @LostKobrakai’s insight, the messages from ex_money are most likely not directly translatable since the test message already embeds the invalid content. This was a poor design choice by me for error handling (true across all the ex_cldr-related libs) based upon my misunderstanding of exception handling back many years when I started all this.

I think you may need to pattern match on the exception module in the {:error, {module, message}} tuple and provide your own translatable messages using @LostKobrakai’s suggestion.

I will work out a way to make this more straight forward for the next release of ex_money but I’ve not thought of a good non-breaking strategy yet. Suggestions welcome.

You can create .pot files manually. E.g. all the ecto errors are available for translation because phoenix generates a .pot file for it. Nothing in ecto itself knows about gettext.